QLD QLD Brisbane northside dyno day part 4 - 5/09/09

In my experience its more exhasut leaks that will effect the reading. On my car the probe was in the rear muffler and the AFR came us almost exactly the same as the theoretical AFR's.


My car also ran lower than last time but raising the VCT point did increase the mid range and smooth the curve out but did limit the top end a bit, gonna try reducing it next tiem and overlay the graph's

Ive said before that i think this particular dyno reads low but id rather that than have it reading falsly high.

 

Definately has more in it, it has been set to what I wanted to ensure it makes the power safely and will last quite a while. On the road the power is alot, but its manners are very nice other than a slight cam lope at very light throttle. On a quick pull with no exhaust, straight out of the dumps it went to just under 550 at the same 18psi, the 28rs's should do 25psi and the engine will go to 8000rpm but it is set more to last and be able to drive rahter than an aggressive all out tune.

 

So you got rid of that big dip in your curve? VTC will affect the top end but not by much. Like we all know, dyno figures dont mean much in the real world, just a good reference for tuning.

 

the 1J soarer that was there would be good competition, 385horse i think. sounded very strong too. Its alot of power for the street.

Hey Drokk, we both have a problem we need to fix though, left hand front splash guard rubbing on the tyre!!!!!

 

yeah it did, i bumped it right up to 5900, which really smoothed it out and it feels alot quicker on the street than before but now the number reads lower. Im reluctant to re tune it since it drives so well.....

 

Yes, very annoying. Only put the 18's on last night, today was the first time I had noticed it.

 

I was also down on power only making 298.9hp. However this was to be expected as I am now running an NA diff so on the graph I have less HP but more torque.

I got 1300 lb of tractive effort

Anyone know how to convert that into something usable, like foot pounds or newton meter?

 

i think sandeep recently found a good convertor

 

The formula is:
T = (TE x r)/(1000 x R)

Where:
T= Motor torque in kg/millimetres
TE = Tractive Effort in N
R = Overall gear reduction including both axle and transmission
r = Rolling radius of loaded driving tyre in millimetres

So in my case

T=?
TE=5772N. (1lb of force = 4.44 Newton)
R=4.03 x 1.00
r=320mm

T=(5772x320)/(1000x4.03x1.0)
=1847040/4030
=458.3

So by this equation I have 458 Nm of torque at the engine at its peak.
Stock torque is 379 Nm.

Can anyone confirm this method of conversion?

 

The resulting figure looks about right. Everything in between is jibberish to me.

 

Pity i couldnt make it

was driving home from work friday night and all of a sudden no forward force when i put the foot down, first thought ive killed another CV joint grr
anyways make a phone call sat morning and i could possibly get a second hand one to get mobile for a short period so i goto remove the shaft to take to the workshop, and low and behold the CV was fine but all the bolts had come undone and out, tightened them back up and away she was going, also noticed some canvas showing on one of the tyres so by the time i got 2 new tyres fitted on the back it was 11am. pity i didnt check it earlier. I'll defently be at the next one im very keen to see what the 944 is putting out.

oh sticky she is running about 12-13psi now so watch out

 

sounds good mate

 

You'll be top of the list for the next one mate

 

heres my pics from the day, based on the weather in the morning i just took the pocket camera and it was auto so the pics are shithouse. underexposed, overexposed out of focus, i know. lol

 

lol do u have a drag car? they usually run around 2000hp give or take, but the most power they can pull from the engin is 7000hp, on methanol+nos, but they have a 10-15plate clutch to to help kill most of that power. and only 1gear...... great fun but expensive to run. 200thousand dollars for 4runs down the strip.

 

what wheels were on it when being tuned? I know of cars that have dropped or picked up HP on dynos with a wheel change.

Either way yours sounded great on the rollers, get some more klms into it and lean ont he tune a bit more and enjoy it.

Niall, might scrape in for the next one will be good to get a final figure out of the ls1 before the stroker ls2 goes in

 

yeah would be good ot get some back to back figures on their new dyno