LS14Winter

It wasnt ideal weather for the track (martin US131), but i wanted to see how it runs out. Before i got inline i spectated and saw what i thought some fast cars turning 14s... so that changed my expectations some.

First pass
2.1 60'
14.7@101mph
missed 2nd gear

Second pass
2.2 60' launched at 3k and bogged really bad
13.8@104.9

actually pretty happy with that considering how slow others were running. No power shifting, bad launch -- im pretty sure if i drove it hard and got a 1.9 60' id be a real low 13 at maybe 106. I dont like to beat on my car so i decided not to make any more passes.

I was shifting at 6500, but every shift drops me out of my optima power band. damn long gearing...

For point of reference, my 2000 trans am with intake, full exhaust, cam did 14.1@101mph at this track. then a few weeks later at mid michigan ran 12.8@110mph.

svede1212

iTrader: (3)

Hi. Where you from? I go down there once in a while. Mid-Michigan has always been a faster track for me but it's twice as far away (been towed home twice from there ). Even with the heat your traps are extremely low for your listed HP. I was trapping 113-115 at that HP level and 104-105 stock. Heat will kill a few MPH but shouldn't that much. I'm waiting for it to cool down a bit before I head out there again.

joeyagls1

Not bad man. I like to see other GTO's numbers. I am going to Norwalk to test my set up. Hoping for good weather and good hook up. As for beating on it, I have feelings for my car and feel bad for it when I gun it, but its an addiction for me. Good looking GTO.

joeyagls1

There is a race for newer model ls cars in Norwalk, Ohio in september. Got a trailer and truck or something should try going, really nice track. I know your from michigan so not to far, but still a drive away.

impulsegoat

iTrader: (4)

That's where i run. I'm fortunate to live within 20 minutes of the track. It's supposedly one of the best tracks in the nation. Very good track prep and gives every driver a great chance at hooking up. Maybe we could get a group of gto guys together to go that day. Would be cool to meet up with some of the fellow gto members.

Glenn B

iTrader: (5)

I think your times will get better with more practice. I used to run my car quite often at the track and my first 4 outings or so were way below my expectations.
I stayed with it and as my driving got better my times dropped.
Couple of the things that helped me the most were finding a good launch RPM and using a good tire that works for your driving style.
Keep your clutch bled regularly too if you are an M6.
No matter what your times are its just good to get out there and have fun!

LS14Winter

I would agree with you -- i expected a higher trap speed, but maybe it makes sense. My GTO actually reminds me a lot of my 09 ZX-6r Ninja.

The ninja is blistering fast once the tach passes 11,000 rpms... .but getting it to 11,000+ takes some time. My GTO and ninja share two things in common. Peaky up top power band and super long gearing. This makes launching really hard because i either spin to much or bog really bad. I know the track is stickier then the street but i was shocked that i really didnt get ANY wheel spin launching at 3,000 rpms. car fell right on its face, then here i am at 3000 rpm making around 200hp instead of 390.

I was shifting at 6500, im not sure where the tach falls after that , but my peak power is around 6300-6400... so im guessing it falls to around 5k ? where im making 360hp or less.

The car weighed 3850 with me in it, 00 trans am was 3750. removed spare tire, 1/4 of gas

Glenn B

iTrader: (5)

I recently put 3.91 gears in my 05 and they really woke the car up.
I agree with you that the gearing in the GTOs from the factory is a bit long- or at least optimized for a lighter vehicle.
Just an idea,

joeyagls1

Your so lucky IMPULSE damn, Im 3 hours away from norwalk. Yeah, my dad races NHRA and goes to race after race, his favorite is Norwalk. It is a good track and sounds like it well made far is rubber laid down and hooking up good. That be cool to meet up, I am putting my car in the trailer for the race, but I can post things up on the race if anybody is interested, I know to drag race its 85, but free test and tune + dyno first come first serve, just let me know I will link you a form.

joeyagls1

3.91 gears are the best, I was told that is perfect for the GTO if you between 400-550hp, 4.10 gears are pointless. I like to have them in my rear i just have 3.46

LS14Winter

How are the 3.91 on the highway? i really like the stock gearing for trips and so on. about 1800 rpm in 6th at 70mph. makes the car quiet and im getting 24mpg+ highway.

My GTO is a daily driver first, so i am really hesitant to swap anything that makes it less friendly daily driver

svede1212

iTrader: (3)

I guess it may show that torque is more important than peak HP. These LS1s have very strong torque down low before they start getting messed with. I know that now when I look at a dyno graph I look a lot more at the torque. HP is just a derived number from measured torque. Torque is what pushes you back in the seat (acceleration). A flat torque "curve" will feel like the same push back in the seat through the whole band.

Something just doesn't sound right with your car. You might have had a happy dyno. You should be trapping 6-8 MPH faster. The cam selection with your heads may be giving you a good peak HP but poor torque curve? The exhaust affects lower RPM torque too a bit if you've changed that. I have 3.91 gears now and they are fun on the street but I don't think they make a big difference at the track outside of having to shift a lot quicker.

409CISecondGen

iTrader: (2)

I trapped 105 after mods. 106 before. Damn GTO wheel hop + 235's.

402GOAT

iTrader: (2)

torque is what launches you out of the hole but a nice healthy hp number is what takes over on the big end of the track.

LS14Winter

Could be a happy dyno.

I am looking at the sheet right now. 360tq from 3000rpm to about 4500 where it goes up to 370ish. at 5252 it starts to head down. by 6200rpm its at 325-330tq

edit. Also on the dyno graph, it looks like when i shift into 4th gear im making about 310hp. I dont start making 390hp until 132mph (4th gear) I think gears would make a big difference to keep me in my "peak power" Would be ideal if my 4th gear ended at like 116mph instead of 135

svede1212

iTrader: (3)

I'm just saying that because I've seen quite a few time slips from different GTOs and know around where a given HP will trap. Frankly trap speeds (with DA) say way more than a dyno number. My first dyno was a happy dyno and read about 50 HP too high. Your peak HP isn't the place you accelerate the fastest. Peak torque is where you are. You'd like to shift near peak HP and drop down to at or just below peak torque. Peak HP is usually near the top and your car's acceleration is starting to slow down there (your torque line in trailing down). When you look at a dyno graph your acceleration rate follows the torque curve. Like I said HP isn't ever measured but is a derived number. The dyno measures torgue through acceleration. The formula is HP= (RPMxTQ)/5252. If you do the math and move things around you'll see why TQ and HP always cross at 5252 RPM.

joeyagls1

Yeah, the RPM launch I been practicing on the street at lights, I can get it up to 1800 till I move. I had drag radials last time when stock now I have slicks Hoosiers on weld stars. So I know I have to pick up there. I was nervous at first but after third pass I was good.

joeyagls1

Thats right haha, nice to have both.