Time for an introduction

[VIDAL BABBOON]

Hi Guys,

Loving the forum and some of the projects that are also on here, i was pointed in the direction of this site for an issue i was having with my ES bushes.
This has now been resolved but not in the way i would have liked, and i have had to go with another make of bush.

Im beginning to find my way around and it's nice to see how you guys do things over the pond, you can never be a member of to many sites when owning an S-Body so i will be in the background mainly having a nose over the tech threads ;)

Anyway i drive a 99 S14 (UK 200sx S14-A)

I have had the car for long enough to forget how long it's been ! and this is my second S-Body.

Things were never planned to go as far as they have done but due to the information and parts that are available for these cars it has gotten a little out of hand.

Im currently trying to keep everything in check and resist further temptation, this is in a vain attempt to keep the car on the road for long enough to actually drive and enjoy it.

Anyway spec and pics time.

ENGINE & TRANSMISSION

Walbro skyline 34GTR fuel pump
Greddy VSPL front mount Inter-cooler
Custom oil catch can
Apexi AVCR Boost controller set to open loop
Blitz Nur-Spec cat back system
Blitz sonic power intake with custom pipe work
Brian Crower 272 duration 12.5mm lift cams
NGK 8 Plugs
Dano de-cat pipe
DB power Custom turbo elbow
Japspeed twin super low down pipe
Race logic Traction control
Race logic Launch control
Race logic Full throttle shift
OBX Short shift kit
DB power Top mount manifold
Greddy EGT Gauge
EGT Tech Temp probe
Apexi Power FC ECU + Hand commander (Custom split install)
Nismo Radiator cap
Nismo oil cap
Battery relocated to Boot
Screen wash bottle relocated to boot
Greddy inlet manifold Matched
Teflon braided turbo hoses
Nismo engine mounts
Nismo gearbox mount
Forge Actuator running heavy duty spring.
Cosworth 1.1mm metal head gasket
ARP head bolts
FSE Free flow over size billet fuel filter
HKS twin plate clutch(GD Max Pro)
HKS twin plate flywheel
Heavy duty bearing and carrier
Large capacity Alloy Racing Radiator
Twin 11" Kenlowe fans in custom shroud
Revotec controller
888 Silicone coolant hoses
Alloy ancillary pulleys
Tomei rocker arm stoppers
Oil cooler and filter relocation kit
Sard 850ltr/min Fuel injectors
Garret 2871 (.86) Hybrid Turbo
Z32 Air flow meter + Tomei loom
Eagle H beam rods
ARP rod bolts
Weisco Pistons matched and cc'd
Decked block for maximum piston protrusion
Ported head
Head Sqish re worked to alter compression ratio
Line honed top and bottom end
ARP Main bolts
ACL Race bearings
Brian Crower double valve springs and titanium retainers
Brian Crower inlet valves (1.0mm oversize)
Brian Crower exhaust valves (1.0mm oversize)
S15 helical Diff in S14 case
Silkolene fully synthetic 5w40 race oil
Silkolene fully synthetic syn25 box oil

SUSPENSION

Cusco carbon front upper brace
Apex front lower brace
Apex 6/4 coil-overs
SRB camber arms
SRB rear toe arms
Apex rear upper brace
Driftworks sub-frame bushes
SPL front toe arms
Polly bushes all round
AVIA Geometry setup
Apex rear lower brace
Up rated drop links all round
Apex traction arms

BRAKES

Goodridge braided hoses
3G 310mm kit with alloy bells
Cusco master cylinder stopper
RB25 Rear brakes
DOT 4 Super brake fluid
DS2500 Front pads
DS2500 Rear pads

WHEELS & TYRES

Rota GTR's
Front - 8.5 x 18 et25 with 225/40 Kumho 712's
Rear - 9.5 x 18 et30 with 265/35 Kumho MX's
Kyokugen light weight wheel nuts
Flush fitting valves
Arches rolled to accommodate rears

BODYWORK

Ganador electric mirrors
JDM rear bumper
Rear bumper aprons
JDM Skirts
S15 Full front end conversion
Glass-fibre front wings
S15 carbon hood
HID headlights
Carbon boot lid
BMW M3 boot lip spoiler
S15 Garage Defend Carbon cooling panel
Carbon fiber front under-tray
S14-A front splitter modified to fit

INTERIOR

Autometer dual pillar pod mount
Autometer 52mm boost gauge
Autometer 52mm oil temp gauge
Autometer 52mm oil pressure gauge
Autometer 52mm water temp gauge
Nismo shift knob
Custom PFC Hand commander install
Dual carbon gauge plate
Driver & Passenger K-sport Fixed Buckets
K-sport 6 point driver harness
6 point passenger harness
Full MSA Fire extinguisher kit
Fabricage 6 point safety cage
OMP deep dish wheel
K-Sport snap off wheel spacer

http://i198.photobucket.com/albums/aa96/VIDAL_BABBOON/Llandow%20track%20day/3333.jpg

http://i198.photobucket.com/albums/aa96/VIDAL_BABBOON/RANDOM/DSC09239copy.jpg

http://i198.photobucket.com/albums/aa96/VIDAL_BABBOON/RANDOM/DSC_1281.jpg

I need to update my shots as these are a bit old now but i like them :)

Thanks for looking guys

PS:Feel free to have a nose around on my Photobucket account as there are many more pictures on there.

[WilloW]

Welcome to NRR! My favorite shade for an S-chassis.

[Your Mom]

theres some cool **** on that car. the wheels kill me thou, p45r or something, the fronts look horrible.

Dyno?
Videos?

[veilside180sx]

Welcome to NRR=)

[stewiefied]

Nice stuff! But yeah the front wheels look awkward with the cool looking ones in the rear. The whole S-body thing reminded me of muscle cars lol. I've only heard them referred to as s-chassis.

[DuckyD]

Rooting around your Photobucket :D

http://i198.photobucket.com/albums/aa96/VIDAL_BABBOON/RANDOM/6666.jpg

http://i198.photobucket.com/albums/aa96/VIDAL_BABBOON/RANDOM/TONYGENGINEBAYSR20DET.jpg

[VIDAL BABBOON]

The BMW with the SR20DET blacktop fitted is my engine builders daily!

I don't have any recent Dyno videos and the only recent chart was from a day when i was only using it to identify a few issues i had (it made 326BHP @ The rear wheels using 1.0 BAR of boost) with very limited traction so the Torque figure is all over the shop.

Im currently running 1.4 BAR :)


I will have some video In a few weeks as im off to the Nurburgring in Germany Next Wednesday for my Yearly holiday and have some new camera kit to test out.

I take it the wheels are not going down too well... they go round don't weigh much and hold the black rubber things on just fine :)
They are the same wheel though it's just the offset and width have been selected to ensure the rear has a wider stance to aid the geometry of the car.

[DuckyD]

I take it the wheels are not going down too well... they go round don't weigh much and hold the black rubber things on just fine :)

They're just hating. These guys must have been spending too much time on Zilvia or something :D I like it.
Got a question for you, the 160mph gauge clusters you guys have over there... you could find me one?

[Tower240sx]

They're just hating. These guys must have been spending too much time on Zilvia or something :D I like it.


I like it too...silly Zilvia fan boys...go eat a JDM Popsicle :cool:

[WilloW]

... im off to the Nurburgring in Germany...
This is me being jealous. :)

[Def]

Nice looking car.

Still a bit perplexed why the UK guys like K-Sport stuff so much, must just be a marketing thing.

BTW - do you really run Ferodo DS2500's on track? I would regularly nuke those things on my stock E36 M3 in a few laps. Only ran them because I was tight on money and got them cheap from a buddy who was the national Ferodo distributor.

[VIDAL BABBOON]

They're just hating. These guys must have been spending too much time on Zilvia or something :D I like it.
Got a question for you, the 160mph gauge clusters you guys have over there... you could find me one?

S14 or S14-A ?

This is me being jealous. :)

:) it has advantages living in the UK

Nice looking car.

Still a bit perplexed why the UK guys like K-Sport stuff so much, must just be a marketing thing.

BTW - do you really run Ferodo DS2500's on track? I would regularly nuke those things on my stock E36 M3 in a few laps. Only ran them because I was tight on money and got them cheap from a buddy who was the national Ferodo distributor.

How heavy are the M3's though ;)

I have run the 2500's at the Nurburgring with no issues, and done countless track days also.

It's the current pad of choice with the track day lads on the sxoc in the UK.

There are a few that are trying the Performance Friction and have been very pleased with them (apart from the huge amount of dust) and then others that like the the Project MU stuff but it's very hard to come by in the UK.

I managed to get hold of a set of project pads (Type HC) and i hated them. Within a few corners they were cooked then it took a few more corners to get them back, it was not an option.

K-sport:

I guess it's the seats and belts you are talking about ?

The price was the reason for them ;) £250 for both seats and harnesses both unused.

My first choice was a nice pair of OMP seats but these were 8 times the price i payed for the K-Sports.

Oh and the snap off boss/spacer was a gift from K-Sport :)

[Def]

My E36 M3 weighed 3120 without a spare in it, so not too far off. Besides, braking requirements on track are dictated by power, not weight, and it was only making 220 rwhp.

No idea how you guys get by with street pads on track, I had to step up to a Hawk DTC-60 to keep the brakes in check. Rotors turn blue/purple and get visible stress cracks after just a few sessions on track(Z32 rotors), so they're obviously getting hot enough to not be happy with a street pad. The DTC-60s will cover the side of the car in dust pretty quickly, and barely respond when cold, so not a street pad at all. Even had my Axxis Ultimates(about the same as Ferodo DS2500s) in the rear finally start giving up the ghost as I picked up speed. Going to step up to some Hawk HP+.

For Performance Friction, try the PF01s out, I hear they're amazing, but a little pricey. They're a real track pad though.

[Def]

On the K-Sport harnesses - that's still pretty $$$, but I understand things are more expensive there. I got a set of FIA tagged G-Force 6 point camlocks for $135 shipped. That's probably about 80 pounds or something like that.

[juggernaut]

Great car....and clearly you've invested some $$$ going by your parts list.

I've also used the DS2500 pad with success at the track when my s15 was mildly modified.

My local track was tightish so speeds only peaked at 200klm's + (125mph+) though. Admittedly, the stock rotors were junk after 7 laps the first time I used these pads. So I swapped the rotors out for some DBA 4000 6x6 wiper slots on the front only and they've been fine ever since. Rears are still fine.

FWIW, the current IPRA (improved production car racing) record at my local circuit (reset earlier this year) is held by an s14 (34mm? restrictor on top mount 2871R turbo) - using the DS3000 pads and the Arizona Z brake package. Not a bad effort since its up against some 6 litre LS2 beasts with AP brake upgrades.

[VIDAL BABBOON]

My E36 M3 weighed 3120 without a spare in it, so not too far off. Besides, braking requirements on track are dictated by power, not weight, and it was only making 220 rwhp.

No idea how you guys get by with street pads on track, I had to step up to a Hawk DTC-60 to keep the brakes in check. Rotors turn blue/purple and get visible stress cracks after just a few sessions on track(Z32 rotors), so they're obviously getting hot enough to not be happy with a street pad. The DTC-60s will cover the side of the car in dust pretty quickly, and barely respond when cold, so not a street pad at all. Even had my Axxis Ultimates(about the same as Ferodo DS2500s) in the rear finally start giving up the ghost as I picked up speed. Going to step up to some Hawk HP+.

For Performance Friction, try the PF01s out, I hear they're amazing, but a little pricey. They're a real track pad though.


Are your DS2500's different to ours in the uk ?

http://www.ferodoracing.com/it/car_racing/ds_2500.htm

Yup the E36 M3 are 3219 lb

The UK 200sx is 2787 lb

A considerable difference even in standard form!

Braking is dictated by power not weight! im not sure you are correct there?

http://www.driverstechnology.co.uk/brakes-discs-pads-calipers.htm

With the same vehicle apply the following

Accelerate to 100MPH with 1000BHP and brake
Accelerate to 100MPH with 100BHP and brake

Now the kinetic energy in both instances will be identical will it not ?

Now on the flip side

Same vehicle with the same power in both instances

Accelerate to 100MPH with a weight of 5000lbs and brake
Accelerate to 100MPH with a weight of 1000lbs and brake

The vehicle with the lower weight will generate less kinetic energy ;)

I could well be wrong though as im no expert on brakes :no:


Great car....and clearly you've invested some $$$ going by your parts list.

I've also used the DS2500 pad with success at the track when my s15 was mildly modified.

My local track was tightish so speeds only peaked at 200klm's + (125mph+) though. Admittedly, the stock rotors were junk after 7 laps the first time I used these pads. So I swapped the rotors out for some DBA 4000 6x6 wiper slots on the front only and they've been fine ever since. Rears are still fine.

FWIW, the current IPRA (improved production car racing) record at my local circuit (reset earlier this year) is held by an s14 (34mm? restrictor on top mount 2871R turbo) - using the DS3000 pads and the Arizona Z brake package. Not a bad effort since its up against some 6 litre LS2 beasts with AP brake upgrades.


I have been told that the 3000's have such a high metal content that it will eat alloy wheels? the local rally lads tend to use them on the impreza and Evo's and the sparks that come from them are crazy !

The stock disks are simply too small, a very common conversion in the UK is the skyline R33 front disk or there are many companies that offer a 310 or 315mm conversion kit at reasonable costs.
The rear brakes are mostly taken from the Skyline R33 or 300ZX and the 350z is starting to become more common too.

[juggernaut]

Can't say I've noticed any sparks coming from the 3000's at the night meetings. Other cars certainly do have though.....its as if there is no pad left Lol.

Yeah I got some GTR R33 Brembo's at home to fit. I'm not sure to go with these now or the Arizona brake upgrade.

[Def]

Are your DS2500's different to ours in the uk ?

They're the same AFAIK. Definitely a streetable pad that can take very light track duty.


Braking is dictated by power not weight! im not sure you are correct there?

http://www.driverstechnology.co.uk/brakes-discs-pads-calipers.htm

With the same vehicle apply the following

Accelerate to 100MPH with 1000BHP and brake
Accelerate to 100MPH with 100BHP and brake

Now the kinetic energy in both instances will be identical will it not ?

Now on the flip side

Same vehicle with the same power in both instances

Accelerate to 100MPH with a weight of 5000lbs and brake
Accelerate to 100MPH with a weight of 1000lbs and brake

The vehicle with the lower weight will generate less kinetic energy ;)

kinetic energy = 1/2*m*v^2, that is correct. I wasn't talking about street braking requirements though, but requirements on track.

You can view a lap on a track as a closed loop system. You've got engine power as the input, and braking as the big kinetic energy "loss" - there are other minor losses, but they can be ignored since they are so minor compared to the braking heat energy created.

So you look at things, and weight isn't an energy input. So braking requirements dictated by engine power, not weight. Otherwise 1300 lb F1 cars would get by with essentially street pads instead of high $$$ carbon/carbon brakes.

Weight might affect some things like how fast a car gets around a track, but if the engine is making X average horsepower per lap, then the brakes are going to have to take that energy away every lap.




I have been told that the 3000's have such a high metal content that it will eat alloy wheels? the local rally lads tend to use them on the impreza and Evo's and the sparks that come from them are crazy !

DS3000s are pretty rotor aggressive when cold from what I hear(the sparks you see), but I don't think they have that high of a heat range. Most people go with more aggressive Hawk or PFC pads here.

[WorkInProgressK]

Def: So you look at things, and weight isn't an energy input.

But it is the flywheel. What saves up the energy from the motor.

So having bigger motor just means you need less time to go fast.

If we take two different objects with different at the same speed, as Vidal said, the one with the biggest will stop the furdest. But if we take the same vehicule, both accelerate the same amount of time, then the one that goes the fastest will stop the furthest. Weight is the flywheel

And F1 uses high$$$ carbon because they need to stop on a dime and have the Super-R-comp to do it. Having an F1 car on street pads is like trying to stop our 240sx from 300km/h to 0 with hp+. Straight into the sand if your lucky.

[Def]

I'm not really sure what you're saying, but you really didn't address my main point of during a lap around the track, engine HP in roughly equals braking heat energy since kinetic energy sums to zero.

[Matt93SE]

Another way to think of it is that with 300hp, your car will be going 150mph at the end of the front straight. same car with 150hp will be doing 110mph at the end of the straight. Since both cars have to enter the corner at 80mph There's a 40mph difference in speed and a huge jump in kinetic energy that must be dissipated to make up the difference.


rough numbers here...
2600lb car, 110mph, EK= 1.43MJ
2600lb car, 150mph, EK= 2.65MJ
2600lb car, 80mph, EK= 0.75MJ

The car with 300hp has to burn off 1.9MJ in heat to the brakes while the car with 150hp only had to dissipate 0.7MJ.


Example #2.

A 300hp car that weighs 2600lb may be doing 150mph at the end of the straight, but another car with same engine that weighs 3400lb will be doing about 130mph at the end of the straight. (assume they both have same corner entry speed due to tires/aero/whatever. this makes the math simpler)
They both have roughly the same kinetic energy since the increase in weight directly affected the speed. Thus they can both get away with the same brake package.

3400lb, 130mph, EK= 2.60MJ
2600lb, 150mph, EK= 2.65MJ

This is eliminating a lot of variables here, but you get the point. The track doesn't change, the mass doesn't change (much), the tires don't change, thus the only variable is engine output affecting the velocity (kinetic energy).

def and I have gone round and round about this in the past. unfortunately he's right on that aspect.
The other end of that story though is that I've had MUCH better luck with brakes on the track than he has. not exactly sure why, but all of my cars have been perfectly happy with DS2500s and rotors last for years.

[VIDAL BABBOON]

It sure does seem like there is some sense in the higher powered cars + braking thing, and there does seem to have already been an in depth discussion on the matter.

So perhaps it's best left at that lol

I know one thing. I am going to be doing some research on this now as i hate having doubt in my mind.

[Matt93SE]

The most recent setup for me is Wilwood Dynalite + Hawk HT-10 + 2-pc R32 rotors. voila.
Hell, they barely get up to temp!

[Your Mom]

Another way to think of it is that with 300hp, your car will be going 150mph at the end of the front straight. same car with 150hp will be doing 110mph at the end of the straight. Since both cars have to enter the corner at 80mph There's a 40mph difference in speed and a huge jump in kinetic energy that must be dissipated to make up the difference.


rough numbers here...
2600lb car, 110mph, EK= 1.43MJ
2600lb car, 150mph, EK= 2.65MJ
2600lb car, 80mph, EK= 0.75MJ

The car with 300hp has to burn off 1.9MJ in heat to the brakes while the car with 150hp only had to dissipate 0.7MJ.


Example #2.

A 300hp car that weighs 2600lb may be doing 150mph at the end of the straight, but another car with same engine that weighs 3400lb will be doing about 130mph at the end of the straight. (assume they both have same corner entry speed due to tires/aero/whatever. this makes the math simpler)
They both have roughly the same kinetic energy since the increase in weight directly affected the speed. Thus they can both get away with the same brake package.

3400lb, 130mph, EK= 2.60MJ
2600lb, 150mph, EK= 2.65MJ

This is eliminating a lot of variables here, but you get the point. The track doesn't change, the mass doesn't change (much), the tires don't change, thus the only variable is engine output affecting the velocity (kinetic energy).

def and I have gone round and round about this in the past. unfortunately he's right on that aspect.
The other end of that story though is that I've had MUCH better luck with brakes on the track than he has. not exactly sure why, but all of my cars have been perfectly happy with DS2500s and rotors last for years.

maybe i've missed the math before but it makes sense now, why couldn't def explain it like that years ago? or did he?

[Jonty]

I can see your point Def, but it's speed and mass that are the important factors, not bhp per say- as VB said lots of us guys in the UK use other Nissan brake systems on the 200sx, which are a perfect example of that it is mass that is critical to performance, not bhp outright; using R33 brakes all round on my S14 I arrive at corners at the same speed as most guys in R33 GTRs that I've seen on track, yet whilst I can do 30min sessions on slicks without a squeak their brakes don't last more than 10 mins and usually have to end up with big AP 6 pots and 356mm disks or similar to get sensible track life.

I will agree with you on the subject of K-Sport though; I don't like the look of their designs as they don't look that well optimised and in particular the brake kits they produce seem to be chasing numbers i.e 10pot callipers, 400mm discs or whatever... I prefer to have a solid R33 GTR brake package that provides all the power the tyres can take and save several lbs on each corner.

Mr Babboon it's good to see a fellow brit over here, I love being able to find info that is geared up towards real track performance instead of people putting snow-plough bodykits on their 200s isn't it?!

[stewiefied]

I was always under that impression also, but these guys are pretty smart and their arguments make a lot of sense. Def pointed out that on a track, power is the input. Weight has some effect on how fast you will be traveling at the end of a straight, but it's just not as significant as the cars horsepower. Then, to further set it off, Matt explained (and showed the math to prove it) how speed difference has a bigger effect amount of kinetic energy that has to be turned into heat by the brakes. The two cars traveling at almost the same speed, with a huge weight difference, had almost the same amount of energy at the end of a straight. The cars with equal weight and traveling at different speeds had a huge gap in energy.

[Jonty]

I was always under that impression also, but these guys are pretty smart and their arguments make a lot of sense. Def pointed out that on a track, power is the input. Weight has some effect on how fast you will be traveling at the end of a straight, but it's just not as significant as the cars horsepower. Then, to further set it off, Matt explained (and showed the math to prove it) how speed difference has a bigger effect amount of kinetic energy that has to be turned into heat by the brakes. The two cars traveling at almost the same speed, with a huge weight difference, had almost the same amount of energy at the end of a straight. The cars with equal weight and traveling at different speeds had a huge gap in energy.

I understand the logic of the argument, but the error is in confusing engine power output with work; work = power x time ...this is the energy that must be dissipated. Imagine 2 cars going down a runway with a lower powered car given a 'run-up' so they arrive at an identical braking point at identical speed- the same amount of work will have been done by both cars, so the same braking effort is required.

I've just spent my last week building a brake test rig for bicycle brake components that uses a flywheel to simulate the kinetic energy of a rider at 18mph, and the power that I use to accelerate the flywheel is completely irrelevant to my testing results. (www.gocycle.com for our product, EU market only at the moment unfortunately, but I'm sure you agree it looks trick :))

...anyway, I've only just arrived so don't want to start off upsetting people- I just like the fact that we're discussing these questions rather than getting excited about gold anodised calipers :D


VB sorry for the above hi-jack, it's cool to see an S15 geared up for track use...my brother and I are rather jelous of you as the S15 is by far and away the nicest looking S-body, but we just couldn't afford the initial outlay- you're a luck chap!

[V1A]

I think what is often overlooked in this argument is that it only applies to the TRACK. Like def said, you have to look at the track as a closed loop system, and when you do, it makes perfect sense. If you use the math that matt provided and imagine both cars on the same track, entering and exiting the same turns on the same line, there is little to argue against. At least I think so.

I think that the biggest difference in braking requirement between drivers of similar cars stems from differences in braking technique. That’s why people have to find a setup that works for them.

[Def]

Yes, you guys are completely missing that I'm talking about the TRACK. I didn't come up with some new formula to disprove kinetic energy theory that's been used for hundreds of years.

As for my brake woes, I've never tracked a car with less than 200 rwhp, and my E36 M3 was about 220 rwhp. The car was fine on little tracks like Little Talladega, but Road Atlanta the car was hitting a hair over 125 mpg on the back straight, and T10A is about 40-45 mph at the apex. At about 3500 lbs with two passengers that's a huge amount of brake energy for streetable pads to deal with. I never knew of anybody that actually drove the track reasonably fast and got by with street pads except maybe E30 318s or similar cars. I touched the brakes 4 other times besides the back straight in a lap, so it's not like there are many braking zones, but they tend to be big.

Speaking of Road Atlanta, I would have loved to drive it without the T10A/B chincane in there. I imagine I'd probably crap my pants heading up to the bridge at 135+ and getting your braking done before dropping down the hill to T12.

[Jonty]

Weight might affect some things like how fast a car gets around a track, but if the engine is making X average horsepower per lap, then the brakes are going to have to take that energy away every lap.

dude looking at your first post here we're on a similar line of thought- you say 'X average horsepower per lap' which is essentially "X horsepower for Y seconds", or Work... so if we're going to call it Work rather than Power then I'm in agreement that that is the energy input :)

Nevertheless saying mass isn't a factor in a track environment I'd still disagree with; rearranging Ek=0.5*m*v^2 to isolate v you get v = (2*Ek/m)^0.5 ...so to maintain a given average v you must keep Ek and m in proportion.

written in prose that says a lighter car with less bhp can set the same lap time as a heavier car with more bhp... and the crux of this discussion that the lighter car will be easier on it's brakes as there was less energy to disspiate.

Maybe we can get a separate thread going about this since several people are interested? It's cool to share ideas like these, but I don't want to clutter VB's thread any further... As he said earlier:

So perhaps it's best left at that lol

Cheers,
Jonty

[Def]

dude looking at your first post here we're on a similar line of thought- you say 'X average horsepower per lap' which is essentially "X horsepower for Y seconds", or Work... so if we're going to call it Work rather than Power then I'm in agreement that that is the energy input :)

Yes, work is energy over time. I was just setting the boundary conditions as being that of one lap, so if you assume it's a closed system with energy in provided by the engine, and energy out simplified down to the brakes since the other losses are so small in comparison. So yes, you can define total work done in a lap if you know some details.


Nevertheless saying mass isn't a factor in a track environment I'd still disagree with; rearranging Ek=0.5*m*v^2 to isolate v you get v = (2*Ek/m)^0.5 ...so to maintain a given average v you must keep Ek and m in proportion.

written in prose that says a lighter car with less bhp can set the same lap time as a heavier car with more bhp... and the crux of this discussion that the lighter car will be easier on it's brakes as there was less energy to disspiate.



I never said weight wasn't a factor. Forgive me for being blunt, but I'm not that slow.

Yes, a lower weight car can turn a similar laptime to a heavier one with less power since their cornering speeds won't vary by a great amount, and the lighter one will need less power to get the same acceleration on the straights. That's why I never said laptimes are a good predictor of brake requirements, as you can run the about the same laptime with a hypothetic 2000 lb 150 HP car as a 4000 lb 300 HP car. The 300 HP car is going to punish its brakes about twice as hard as the 150 HP car. Keep in mind a 2000 lb 300 HP car would have similar braking requirements and peak brake temps with the same brake equipment as the 4000 lb 300 HP car. The 2000 lb car is just going to be going around the track much faster.


Get what I'm saying now? Braking requirements ~= Engine Power output *ON A TRACK*. That's all.

[VIDAL BABBOON]

Man this is a cool thread.

Like my fellow Brit mentioned it's nice to find a forum where there is more track orientated info available and less of the pretty paint and wide arch mess going on.

Oh and the Nurburgring was fantastic :) met 2 guys from Cali over there and they were about to go out in a brand new M3 ! no prior experience of the track lol

Hope they managed to have a good time and keep it on the black stuff!

I have some links for pictures that were taken and some video footage that i will put up shortly.

The car was fantastic although i had a few issues but nothing serious (one being i was only able to push 1.3 bar of boost) i was getting used to the new rear sub-frame/brakes/diff/suspension geometry setup so no mind blowing laps yet all were 10 Min's ish.

I now have the confidence in the car to really give it some next visit (perhaps September this year) and you will see that caution was the order of the day during this visit lol, i did have to drive home in the car so bending it was not an option ;)

http://www.nordschleifenbilder.de/go/albums/uploads/nordschleife/autos/2010-04-29/IMG_1586_J.jpg
http://www.nordschleifenbilder.de/go/albums/uploads/nordschleife/autos/2010-04-29/IMG_2157_d.jpg

http://nurburgring-photos.fotopic.net/p64580010.html

http://nurburgring-photos.fotopic.net/p64579654.html

I need to edit the video's but will get them up ASAP :)

Nick

[Matt93SE]

I think the connecting issue that Jonty is missing is the closed-loop system. i.e. the track. You have finite lengths of straights so that your point about a longer runup to the same speeds is taken away.

If you consider two cars with varying weights on a straight, infinite length road, then yeah, the heavier car will have more kinetic energy and thus harder stop since the straightline speeds are goign to be nearly the same. (Assume both cars have identical aero, same HP, and differing weights. the final speed will be limited by power, not weight or aero.)
This is a great simplification, but it should illustrate the point.

To further your example with the R33 and the 200SX, how fast are each of you going at the end of the straight? how much power does your car- that's easy on brakes- have compared to the R33s that are eating brakes alive?
What are your end-of-straight speeds and your turn-in speeds compared to those cars?
How much power do each of you put down?

The R33 may weigh 1000lb more, but that means in order to run the same speeds as your car, they must be putting down a lot more power to do it. thus power is the main variable in the equation.

[V1A]

The other thing, which I hinted at in my earlier post, is that driving technique is going to be a part of this equation too. If 2 people, one more experienced than the other, drive the same car on the same track, there will almost certainly be a difference in brake temps.

A more experienced driver is more likely to brake later and faster, deep in the braking zone. Less heat is generated when doing so. A less experienced driver is more likely to get on the brakes early, and brake over a longer distance, increasing brake temps.

[VIDAL BABBOON]

Video of my first lap on the 30th.

http://www.youtube.com/watch?v=4yvPmDvDa9w

Temp on the the 29th was 31 degrees and the track was very nice, then the temp dropped overnight and it was quite cold on the 30th making the track completely different to drive!

The tyres took far longer to get to temp and all in it was a challenge, but made for a good time all the same.

Im no full on race driver and have only ever done a hand full of laps of the Nurburgring so i still have much to learn.

Anyway enjoy and i have one more to come.

[VIDAL BABBOON]

Lap two from the 30th

http://www.youtube.com/watch?v=431VikqCODE

[VIDAL BABBOON]

Well i have been busy with the car over the last year and some things have changed.

Car has also been on the rolling road for a heath check and power run, it was then noticed the BC cam on the exhaust side is a big issue for my build.
This was passed onto my builder who got in contact with his connections, Between them they have made me a cam that is suited to my engine.
Things have stalled a little on this due to my builder having family issues, But as soon as it's done it will be back on the rollers to prove the modification.

I finally found the limit of the brakes during a track-day. So threw caution to the wind and went for massive overkill by fitting some 356mm 8 pot fronts with Performance friction PF01 pads, And i fitted the R33 GTS rear brake set-up.
I have used this in anger and as yet i have not found the limit, stopping power is immense to what i previously had

I was also having oil loss issues and this was eventually found to be an oversize valve guide or two, The head was removed and new phosphor bronze guides were made and installed along with a fresh set of seals.

While this was all going on i decided to top mount my turbo, Mainly to make working in the engine bay easier (Why i didn't do this at the start is beyond me as it's so much easier to work on the engine now and much faster too) This also improved spool and allowed for tighter boost control.

Then I began to have coil pack issues and the easy option was taken, fitted a new set of splitfire coils and controller.

I don't have any up to date shots of the car at present BUT I will get some ASAP

I do have one of the engine bay though

http://i198.photobucket.com/albums/aa96/VIDAL_BABBOON/Engine%20build%202007/Engine%20bay%20refresh/a3.jpg

Will also scan in the Rolling road results, But at sensible boost it was 345BHP@wheels and that's exactly where I wanted it to be at the start of the build. However with more boost it's a handful lol

Sure there is far more work than that but will add in as i go from now on ;) Still plenty more to do....

[VIDAL BABBOON]

Well here is the latest rolling road graph, Notice the late spool as a result of the incompatibility of the cam.

http://i198.photobucket.com/albums/aa96/VIDAL_BABBOON/Engine%20build%202007/img003.jpg

OK I'm really Happy with the general result. But due to the late spool, Drive-ability has been affected slightly.
On track I'm having to change down in places that I should just be able to reduce the revs and keep in gear.

Once the new cam and pulley has been fitted, It's off to be remapped to make full use of this and other upgrades that have been installed over the last 12 months, then off for another session on the rolling road.

My latest issue is tyres ! I'm using Hankoook RS2's and having a hard time getting them up to temp, More so in the wet as the side-walls are solid even with much reduced pressures.

After asking the right people. I'm not the only one to have issues with the RS2's.... So I'm going to switch to Federal 595RS-R's. Others are having good results with them in both wet and dry conditions.

If this fails then I'm back to the old faithful Toyo 888's. But these are fast becoming a rich man's tyre, I'm certainly not rich enough for the amount I can get through!