Road Race setup/ Track pics

[WhiteGLX]

the head checked out good....no problems, still flush, and no cracks anywhere, waiting on HG and some other seals before reassembly, then everything goes back together this weekend hopefully.

[WhiteGLX]

engine is up and running, with only mild adjustment to the ignition timing after startup, turns out im getting pretty good and timing, almost spot on without timing light, i was at 16* BTDC instead of 15*.

brake ducting starts tomorrow, and the old suspension goes on until i can afford a set of Stance coilovers, a week or two prolly.

[WhiteGLX]

Brake ducting done yesterday. I used 2" Scat tubing from aircraft spruce with high temp rating. I attached it to he back of my dust shield with a pinched 2" piece of tubing. The front attaches to my bash-bar for the most strait on opening for best air flow. I will post pictures later when i get a chance.

[WhiteGLX]

[Paul2x]

Very cool, i'm currently working on a simular set-up

looks good! =)

[racepar1]

I think you should build a radiator/intercooler duct and incorporate the brake ducts into that. I plan on doing that for my car whenever I get the time and motivation to repair/install the front bumper cover that I have had sitting around for like 4 months. I keep putting it off because I have to devise a mounting system for the bumper that will mount it very solid, as it is an aftermarket fiberglass bumper, and incorporate some mounting points for the front splitter/diffuser (which I also have to build myself). And then on top of that I have to build the radiator and brake ducts and leave a provosion for an oil cooler duct in the future. And yes I know that I'm slightly nuts for undertaking this project, but it's not my fault I was born that way! LOL!

PS: Paul what happened with the event you were talking about putting together?

[WhiteGLX]

i will be making ducting eventually, but its not priority. The brake ducts need something better up front bu ti had very limited options so current location it is until i switch to a different front end or until i move my oil cooler.

[steve shadows]

Originally Posted by WhiteGLX

I need to do this...like very badly haha before the next track day

[WhiteGLX]

it wasnt too bad on labor time. I spent more time trying to figure out where up front to mount the tubes than anything else.

[racepar1]

Originally Posted by steve shadows

I need to do this...like very badly haha before the next track day

Ya steve 400hp + no brake ducts = Lots of fade and most likely smoke as well! If you can afford it you should just get the kognition ducts. They actually duct the air through the vents in the center of the rotor, which is more effective.

[WhiteGLX]

i saw those available for Z32 and 350z i think. I have mine setup pointing right towards the center cavity behind the hub.

[racepar1]

Ya Your set-up isn't bad at all, but the kognition ducts are just a bit more effective. Since I took my dust shields off years ago my only option is kognition or I have to custom make something myself. With all the other crap I have to make I think I'll just go with kognition.

[steve shadows]

Does anyone else think that in the Japanese car racing circles there is over use of spring rate? I mean I see this all the time, too much spring, and anything other than a slick.

I mean most chasis that are not half backs or fully cages - chasis prepared are not going to bend well to stiff spring rates.

I guess I need to try the NT01s out in a nice width before I go down in springs rates or go back to GC (but Koni this time) with less spring.

[bungl3]

Originally Posted by steve shadows

Does anyone else think that in the Japanese car racing circles there is over use of spring rate? I mean I see this all the time, too much spring, and anything other than a slick.

I mean most chasis that are not half backs or fully cages - chasis prepared are not going to bend well to stiff spring rates.

I guess I need to try the NT01s out in a nice width before I go down in springs rates or go back to GC (but Koni this time) with less spring.

i agree with that......in the uk i see people going for stiffer springs all the time (often with very poor dampening) and then backing off their uprated arb's to near standard settings

im not heavily clued up on suspension set ups yet but to me that seems wrong?

[racepar1]

Originally Posted by steve shadows

Does anyone else think that in the Japanese car racing circles there is over use of spring rate? I mean I see this all the time, too much spring, and anything other than a slick.

I mean most chasis that are not half backs or fully cages - chasis prepared are not going to bend well to stiff spring rates.

I guess I need to try the NT01s out in a nice width before I go down in springs rates or go back to GC (but Koni this time) with less spring.

I totally agree. I think the ideal spring rate for an s-13 is 9-10kg in the front and 5-7kg in the back. I am running 9 and 7 right now, but I wanna try dropping my rear spring rate to 6 and maybe after that up the front to 10. I'm not looking for a huge change, just trying to fiddle with the balance of the car slightly. I won't change anything untill I get my hankook r-compounds though. R-compounds for $0.00! Raffles RULE!

[mmdb]

Concerning softer spring rates: According to Paul van Valkenburgh's book "Race Car Engineering & Mechanics", for a grip setup, you want to run the softest spring possible. Here's a quote from the book, "The essential criteria for springs, with respect to race car handling, is that they be as soft as possible, without allowing bottoming, and that they be relatively well balanced from front to rear." The author later goes on to explaining the effects of bottoming out a chassis.

In my experience when I dropped my spring rates from 11kg/9kg fr/rear respectively (recommended by a well known differential company) to 9kg and 6kg. With the prior (11kg/9kg) the car was definitely on edge through cornering (transient & steady state), resulting snap oversteer on corner exit and decrease in cornering power. When I switched to the latter (9kg/6kg) the rear planted much more smoothly on corner exit, more cornering power, and made the car feel less "darty".

Moreover, I'm currently having suspension made by ast (ast-usa.com), also known as Aragosta in Japan. I gave them specifications of how my car handles, weight distribution, power, tires used, and they recommended that I run 5.5kg front and rear. Although a bit surprising from the norm of seeing 2kg difference front and rear (ie 8kg/6kg f/r), it's reasonable from what I stated prior.

Hope I helped!

[a_ahmed]

Aceinhole is running 600lbs/inch (10.7kg/mm) front and 450lbs/inch (8kg/mm) rear. Front whiteline swaybar with heim-jointed endlinks set to stiffest setting, no rear swaybar. He has koni 8611 front, koni 8610 rear, this is on an s14 with an hlsd.

I will be getting the same... 600lbs/inch 6" front, 450lbs/inch 6" rear, except koni 8611 front and rear, and well i have stock swaybars (rear hicas swaybar). Also ebay/bings style endlinks lol with the theromplastic shit removed for whiteline polyurethane lol... will see how this works for me... I just bought an hlsd too.. i am so frickin excited to try it on the track... i guestimate finish time on my car end of may If I get everything in time...

I guess this may be more suitable for autox and softer springs may be more suitable for road racing... but i will find out soon enough. Can always change springs.. but in the end it may also be the dampers themselves and how well suited they are to the car's sprung and unsprung weight.. reason why i went with the double adjustable koni 8611 in the rear as well to toy with it...

[WhiteGLX]

As far as i know for road racing, Alot of ITA 240sx racers used to run about 650lb front and 450lb rear. These were actual race cars not HPDE people with minimal track experience. usually they ran Koni yellows and GC camber plates.

i personally plan to run about a 7k F and 5k R. Which should be stiff, btu not enough to force the chassis into an oversteer situation at cornerexit.

[bungl3]

whats the theory behind no rear sway bar?

i assume as youre running a hlsd you want both wheels in contact at all times and so the rear sway bar hinders traction by slightly lifting the inside wheel?

[racepar1]

The car just seems to bite better without the rear sway. At the autocross at the performance nissan meet I was basically sliding the whole course. After I dis-connected the rear sway the rear just had more grip. I was still sliding, but it was much more controllable and less sliding total. I believe that it is related to the massive amounts of anti-squat designed into the rear suspension of the s-13's that causes it. It basically binds the rear suspension to prevent squat, which in turn transfers less weight to the rear tires. Removing the rear sway bar allows more weight transfer to the outside tire, which helps it bite better.

[bungl3]

aaahh i see, but wont that induce more understeer leading into the corners?

sorry for the quizzing but no one over here even talks about disconecting the rear arb.......tbh no one discusses suspension set ups at all.....its like one big secret

[racepar1]

I didn't really notice any additional corner entry understeer, but it was a very small course so I can't really give a definite judgement there. I should be going to a real track on the 11th of next month so I coulld answer this question better then.

[bungl3]

cool beans cheers bud

need to borrow someones 13 i think and have a play

[WhiteGLX]

this is all true, the no-rear sway theory is an old school ITA cheater method to getting more grip and holding more exit speed. I have been preaching the no rear-sway or stock rear and more front sway for quite some time on here, most people usually think i am bonkers, but it works.

[Rexbo]

Originally Posted by WhiteGLX

this is all true, the no-rear sway theory is an old school ITA cheater method to getting more grip and holding more exit speed. I have been preaching the no rear-sway or stock rear and more front sway for quite some time on here, most people usually think i am bonkers, but it works.

It very much works! On larger high speed courses like Buttonwillow and Laguna Seca it leads to much more planted rear ends through corners, but it can lead to some off-throttle understeer on smaller courses like Streets of Willow. It also helps heaps over broken pavement with traction!

[eye-5]

I have done much tuning with FWD cars. I am just starting on RWD with my 240. I have no rear sway currently and have massive oversteer problems at the moment. I'm gonna start with a bigger front sway then go from there. The car came with crappy Tein Basic coilovers at 6k front 6k rear spring rates. The funny thing about them is they feel much better than a set of the Tein Flexs I had on another car. The Flexs were just massively over dampened. These seem appropriate so far.

[racepar1]

Originally Posted by eye-5

I have done much tuning with FWD cars. I am just starting on RWD with my 240. I have no rear sway currently and have massive oversteer problems at the moment. I'm gonna start with a bigger front sway then go from there. The car came with crappy Tein Basic coilovers at 6k front 6k rear spring rates. The funny thing about them is they feel much better than a set of the Tein Flexs I had on another car. The Flexs were just massively over dampened. These seem appropriate so far.

Toe in the rear 1/16, big front sway bar, stiffer front springs, etc... Flexes overdampened!!!??? Are you smoking something? My flexes seem just a bit underdampened at the track as the car is just slightly bouncy over the "whoopty doos" in turn 8 at big willow.

[eye-5]

My flexes were for an Acura RSX Type S so they were probably different for that application. They were way overdampend. I had to run the fronts all the way soft, un hook the front swaybar and they still wouldn't keep the tires on the ground. I switched to buddy club RSDs and they were 100 times better.

Thanks for the tuning advice! New coilovers arent in the budget till next year so big front bar and alignment it is.

[WhiteGLX]

Originally Posted by racepar1

Toe in the rear 1/16, big front sway bar, stiffer front springs, etc... Flexes overdampened!!!??? Are you smoking something? My flexes seem just a bit underdampened at the track as the car is just slightly bouncy over the "whoopty doos" in turn 8 at big willow.

you love the toe-in so much.

[mmdb]

Here's a good article written by Sports Compact Car dealing with increasing lateral grip on a skid pad via suspension spring rates, differential, dampening, and sway bars. The article also states how the car behaved after installed a torsen type differential from Quaife which I found to be most interesting part. I usually wouldn't throw the differential in the equation of how to determine what's causing understeer/oversteer.

Article Here