PDA

View Full Version : 1/4 mile runs...a bit disappointed! What gives?



owensmat
11-09-2009, 08:11 AM
Hey guys,
Took my 08 GT to the track. Had expectations, but not too high....didn't even meet those. Wondering whats going on here. Hurts my feelings a bit when guys on here with only a tune and 100 shot are kickin my ass! LOL. Seriously though? I was hopin for a 12.2-12.3, with I felt was a quite reasonable expectation. Weather was great. 65 and sunny.
Here's a bit about my car performance wise, then I'll list my times. I'll try to post a pic of the slip, but last time I tried to post a pic I fumbled it up?? Lemme know whatcha thinks goin on here? BTW: The runs were on aftermarket 20s with Nitto street tires. That has some amount to do with it, but still, checkout my 60ft....the tires don't seem to be the problem. Thanks!

08 G8 GT, procharged (approx. 9psi), 65lb fast injectors, BAP, 3200 stall, Kooks 1 7/8 LT High Flow Cats, X-pipe and stock GT muffs.

60 ft: 1.7579
1/8 ET: 8.0136
1/8 MPH: 86.92
1/4 ET: 12.5267
1/4 MPH: 108.18

GRRRR8
11-09-2009, 08:27 AM
Whats your A/F on the big end? If I had to guess you are running out of fuel.

The 60ft is good enough/ About what others are running that are going faster.

How much RWHP are you putting down?

MGM GT
11-09-2009, 08:37 AM
Yeah something is wrong there... your running slower then I am with boltons but you have a better 60'. Your MPH is wayyy low, somethings going on in the big end. Could be fuel, belt slip, tire spin, slow 3-4 shift...

Who tuned it?

I can't read that slip at all... haha.

fiveoh
11-09-2009, 08:49 AM
My guess is tune. You posted in the other thread about the CEL that you have NOT had it dyno tuned just a base street tune put in. Take it in and get it dyno tuned by a good tuner and get some before and after tune numbers.

owensmat
11-09-2009, 08:52 AM
Sorry about the slip being illegible. I crumbled it up after my run, to throw it in the garbage. LOL. Thats why I wrote the times out too, in case it was illegible. I'm not sure what the A/F is on top, as I'm still waiting for a final finishing tune (long story there), but I do have a BAP and was told by the tuner that I'm gettin plenty of fuel now. Waiting on the final numbers too, but am supposed to be around 450-460rwhp? I didn't have much spin out of the hole, but I chirped 2-4th, but only slightly. The car felt good going down the track. Smooth, steady and strong. The numbers just didn't look good, given my car and the mods, etc.

fiveoh
11-09-2009, 08:56 AM
There is no way you are making 450rwhp and trapping 108. More like 350rwhp. Are you going to put it on a dyno?

owensmat
11-09-2009, 09:07 AM
long story with the dyno. Short version goes like this. Initial dyno tune with one pull on the dyno indicated likely bad gas, but still showed 420rwhp. Brought it back with fresh gas and had the Kooks installed, but the dyno computer broke before the car could be tuned. I needed the car back, for various reasons, so the tuner then ran it on the dyno, but tuned it with a laptop and he felt that it was very close to what he would expect from the dyno. Now, I'm waiting on the dyno to get fixed to get it squared up. Still though, if it was showing 420 with bad gas, we were expecting around 460 with fresh gas and the new Kooks installed. I don't know. So, not really sure about the numbers or the tune. I'll have to wait and see. I do know this though, there was a before/after difference from the kooks. I noticed stronger low and mid range power and a more steady powerband, but maybe not quite as strong on top?? NOt sure if that helps?

familycaronROIDS!
11-09-2009, 09:55 AM
What state are you in?? Go to a tuner with a good rep who knows what he is doing..

Damm I trapped 107 with my mods and bad weather DA3050....

G8GXP4now
11-09-2009, 09:57 AM
The runs were on aftermarket 20s with Nitto street tires.

How heavy are the aftermarket tires?
Are the Nitto's drag radials?

Patrick G
11-09-2009, 10:14 AM
long story with the dyno. Short version goes like this. Initial dyno tune with one pull on the dyno indicated likely bad gas, but still showed 420rwhp. Brought it back with fresh gas and had the Kooks installed, but the dyno computer broke before the car could be tuned. I needed the car back, for various reasons, so the tuner then ran it on the dyno, but tuned it with a laptop and he felt that it was very close to what he would expect from the dyno. Now, I'm waiting on the dyno to get fixed to get it squared up. Still though, if it was showing 420 with bad gas, we were expecting around 460 with fresh gas and the new Kooks installed. I don't know. So, not really sure about the numbers or the tune. I'll have to wait and see. I do know this though, there was a before/after difference from the kooks. I noticed stronger low and mid range power and a more steady powerband, but maybe not quite as strong on top?? NOt sure if that helps?As mentioned, you are either getting major belt slippage or your tune is way off. Agreed that your mph shows you are putting out around 350rwhp on the big end of the track.

-Ray-
11-09-2009, 11:17 AM
Lets hope it isn't too lean. Even at the 1/8 mile you seem slower than others with your HP and 60 foots.

NYG8GT
11-09-2009, 11:47 AM
Another blower car running only 1mph faster than me up top. I want to race both these guys on the highway before they get their tunes fixed lol :p

owensmat
11-09-2009, 12:22 PM
The tuner and shop is very reputable and well known (don't wanna put any possible negativity out there about them) Its gotta be the tune, or maybe a belt slip that was suggested? The tune needs to be finished up on the dyno, once it gets fixed. The belt checks out fine though? The tires are Nitto 555 street tires 255/35/20, with KMC Strike wheels. The rims are probably a bit heavy and while that could make a difference, it shouldn't make that much of a diference; I wouldn't think.