awilson40

Here are some before and after Gtech Graphs. One is HP the other is a 0-60. These are under the same conditions, same road and several runs were performed with very repeatable results. The 0-60 wasnt overly hard with no wheelspin or slipping the clutch. Other than the items in the sig I have gutted the cat and am just kissing 16psi falling off to 12-13 at redline.
The lower readings are with stock chips and a reliaboost kissing 13 psi falling to 10 at redline.

awilson40

Heres, the HP graph.

streckfu's

5.2 seems quick for 233hp. Could there be other factors?

I have 250rwhp and my best is about 5.6/7 with a good launch.

jsonnen

I think upgrading to a Tial wastegate or similiar would be a big improvement up top.The stock wastegate isn't holding the boost as good as a aftermarket could. just my 0.02 cents.

rcatherton

The chart shows the car is doing 4 mph at the start and the shift points are up on the higher H.P. run.

awilson40

You're right... I went back and checked...I had the roll out set to 12 inches cuz I seldom stress the car with launches. I should have set the roll out at zero,my bad. The roll out time is .47 seconds, so thats a 'true' 0-60 of 5.7.
And you have to remember that above 60mph air resistance really makes the HP reading show lower than on a dyno. And the shift points are higher cuz the chips raised the rev limiter.
But is great as a before and after.

streckfu's

That's more like it. Nice.

awilson40

I just checked with G-Tech and 5.2 sec is the true 0-60. The software includes the rollout time for time calculations and after looking at the plots I see that it does.
Cool.

streckfu's

Wow. That's fast for you hp. Outstanding.

944Willie

I have not had the weather (dry) to test my car with my G-Tech Pro. I want to do a test with my stock PD's, stock rubber size. Then I am switching to my new 17" Fikse with S-03's, 245 & 265. It will be nice to get dry weather. It would be too much to ask for weather above 50 degrees.

Tony

Rear end squat, the down fall accuracy wise of accelerometers. The tipping aft of the device induces a false acceleration.

BoostGuy951

Tony you are correct. A stiffer suspension will show your Gtech results to go down.

Although, 0-60 is all about traction.

I ran a 4.55 0-60 on the GTech with these mods:

- Gutted Stock cat and muffler
- APE Chips @ 19 psi
- Beru Plugs and Magnecore wires
-LBE

But these Traction factors:

- Cup Clutch
- 10" Nitto 555R's
- LSD Tranny
- Gear Changes were .15 seconds from the time the clutch was depressed to the time is was let out and engaged.

Although the average was about 4.7. I consider myself pretty damn good at launching. That 4.55 time I slipped the clutch just enough to keep it just at the limit of adhesion for the initial launch. I was running 10 Inch back rubber that would hook up very well if you knew how to feather it. The 1/4 time on that run was 13.1. The Gtech has been dead on with every one of my friends to use it. My car was the only one to get a surprisingly good time.

awilson40

The Gtech Pro- Comp is a 3 axis accelerometer and is suppose to be much more accurate. I have been very impressed with the repeatability. Every upgrade I have done I was able to see incremental improvements.
I do several runs on the same road in opposite directions and I will only see 10 HP and 10 TQ variances.
Sometime I want to head to a dyno and compare.
When stock I was doing good to get 0-60 in 6.8 sec.
The day I did these runs I did 3 , each trying a harder launch
I did a 5.6. a 5.4 then this 5.2

Robby

Sorry I missed this thread... Is that wheel HP OR Flywheel? Streckfu mentioned the correlation b/t time & HP- the stock Turbo S rana 5.5 & it had 247/258 flywheel- I DO think the Turbo S's seem to show better on the dyno compared tpo normal turbo's- I mean that the dif b/t the two cars seems to be more pronounced on the dynos than the factory flywheel ratings would show- anyway, I ran a 6.1 w/my turbo S & a 1/4 opf 14.6 @ 101.9 w/a regular G-tech- I'm aware there are many variables w/those things, but, my G-Tech has proven to be VERY accurate- although the speeds at the 1/4 tend to be a little high, BUT, they say that's b/c the G-Tech shows the actual speed, whereas the tracks take an average of the last 100ft or something like that(?). Anyway, on my ONE run, I gave it a really gentle launch & shifted very carefully, so, I'm very convinced the car could run a 5.5/14.2 bone stock like the magazine's showed. The cars really need a good bit of wheel spin to keep from bogging down & wasting time- of course, TOO MUCH wheel spin will slow you down, but, I've found that spinning close to half way through 1st is about right, but, it's controlled spinning- an extra 100HP would probably make this an excersise in futitlity though- would probably just burn the tires off too much & get nowhere- I've noticed that w/stock HP levels, the cars will really throw your *** into the seat & keep going hard, even while spinning- the LSD is on 40% lock, which is a lot for a street car- many BMW's of the era were on 20%.

Anyone ever check their BRAKING distances? I would love to hear a few of those- I'm going to check mine again w/new tires & 17" wheels, as soon as I get my susp sorted out.... I was getting ~122ft, from 60mph, & was not very happy w/that...

awilson40

Its rear wheel but it also includes wind and road drag.
I found a site which calculated HP losses at various speeds
taking into account the CD and frontal area.
here is a .jpg with that loss drawn in on the Gtech graph
showing aprox RWHP without aero losses.