I have an issue that perhaps some of you may have experiance in.

Supposedly my car is making around 500rwhp according to my local rotary mechanics dyno. Its a roller dyno, dyno dynamics i think.

My question is would a 500hp car not spin the wheels in 3rd from 60mph when you gun it?

I have goodyear eagle F1 255 tires and they spin through 1st an 2nd. My suspension is Tein Flex and fully corner weighted and setup up by a professional racing suspension guy.

So am I not wheel spining due to a good suspension setup and tires or am I not realy making 500rwhp as the dyno says.

A friend of mine had the same turbo setup making 430rwhp and was able to spin the wheels from 3rd at 60mph, of course not instantly as the turbo has to spool up. He has 245 tires and greddy suspension but not fully setup.

Im very interested to know if any of you have wheel spin issues like this.

 

i would think it all has to do with how the turbo 'hits' when i had a half bridge with a t66 in my car i could get wheelspin in third by just flooring it and waiting for the power to hit. that set up only made 450 whp but the power came on like a light switch. at the same time i've driven fd's with 500 whp that can only spin tires by powershifting into a gear. theres lots of 500whp cars that will not spin tires from a roll in third. our motors simply dont make the kind of torque to do that stuff regularly. if you posted a dyno sheet it would be easier to see whats going on.

so to summarise, yes its very possible that you are making 500 whp at some point in your rpm range and not able to spin tires simply by flooring the gas at 2000 rpm in third gear.

 

Thats great, its good to know there are people with lots of experiance out there.
Thanks so much. I will post a pic of the graph later on when I get home.

 

I made 512 rwhp and can't break the tires loose in any gears by just hitting the gas. Stock suspension.

 

You telling me if you lay into it in 2nd gear it does not spin at the top of the gear? You must be runing those et streets daily!

 

Haha Na im sure he will loose traction. I think he was just meaning in different situations.

I loose traction in the low down like 1st an 2nd but after hooking 3rd it grips and goes.

 

Ok heres the graph.

Its in KW but 440KW = 588HP

I dont know what the dip in the graph is, perhaps the ignition or something.
We were runing 7 and 9 plugs with water injection but they soon died on the track the day after the dyno tune. I have some HKS race plugs now.

I will see if I can get it back on the dyno and see if the new plugs make a difference.

 

Delslow made 531 on a dynapak(reads lower than the dynojet's) and he had no traction problem at all, 20 mph roll in 1st gear, solid hook up. But then again, it was a 17 year old suspension, HAHAHA.

Jackson

 

Thats right no wheel spin at any rpm in any gear.

Nope, run Khumo Ecsta MXs, 255 40R 17 on that street.

 

no wheelspin in lower gears is probably just a combo of slow spoolup/good grip.. not enough boost in 1st or 2nd to make them spin. im only making a little over 300rwhp with fairly quick spoolup, and it will spin in 1st and 2nd.. but this is with 205 tires, tein suspension

 

I make all 22 psi in first and have verified with data logs.

 

You either have a pretty **** tune in that car or there was a bad tach signal when you were dynoing. Try plotting that same graph with wheel speed as your x axis and see if the graph cleans up...

 

No tune is very good. 11.3 AFR throughout the rev range. As I said we had stock plugs in and that was the last run. On my other sheet with all the graphs on it there were no dips like that.

I still want to put it back on just to make sure its all good. I drive around on 15psi 90% of the time as I drive the car often to work.

 

I have another question. Do all of you still use the stock gearbox and diff?
The guy I refered to earlier that could spin his wheels in 3rd said he broke his gear box and diff because of the power.

I have thrashed mine around a track a number of times now and its still fine. I use redline oil in the box and diff.

 

Transmission is fine, you need to get a new diff though. Either a S4TII diff or a Kaaz.

 

drag radials and 18x10's

 

Or a cusco or mazdaspeed or 03/04 cobra, lots of choices out there.

 

Traction control?

 

Nope.

 

Ok, here's what you do. Get in third, gas up until you're at or above 5k. Then gently apply the brakes with your left foot *while* accelerating to WOT. Keep applying the brakes so you don't speed up. Let to boost build 'till it's maxed out. Then let off the brakes and HOLD ON.
It's called pedal braking. Your using the brakes to pre-load the engine before releasing that energy into the driveline.

 

The normal term for it around here, is "brake boosting," and i'm pretty sure everyone that has made any highway pulls if familiar with it.


Actually, brake boosting is about the only time i'll start spinning while i'm moving and not banging a gear. Hold the brake at about 6k rpms in 2nd and hit 22 psi and it will start smoking the rear tires while not accelerating.