Iron Indian

I have a 2005 GTO. It's a full weight, full interior, A/C, 6 point Chrome moly cage car. In street/track trim it weighs 4,030 lbs with me (250 lbs) behind the wheel. I've been a PB of 10.52 @ 129 w/ 1.50 60ft. Been running Nitrous for 3 years. Here's the run down of my mods, it's a very simple setup.


-Cam Only LS2 (EDC Streetsweeper XL) stock block, stock heads, stock intake, stock TB
-O-B-X Headers 1-7/8" x 3", Catless Mids 3" / 2.5", and 2.5" catback
-Nitrous Outlet 175 Shot Plate Kit with NOS Mini
-50lbs Injectors
-DW300c Fuel Pump
-Tim Haines Remote tuned via HPT PRO
-RPM Level 7 4L65
-FTI 3800 Stall
-DSS 9" IRS Rear end w/ Tru-Trac and 3.70 gears
-15x4 Skinnies
-15x8 MT Pro Bracket Radials 28x9
-Pump Gas 91 Octane


I not sure how much more my 90k LS2 can take. I don't think it would be very wise to put on a set of heads on this motor. I'd rather put that towards another motor, I'd like to eventually build a motor for this car built for spray in mind. For now I plan to work with what I got until this motor dies. I do not plan on purposely killing it though.

Only thing I plan to add for next season is a Stand Alone setup and likely run C16. Not sure how much of a gain (if any) I'll see from this coming off a rail fed 91 Octane pump gas setup. I plan to keep 91 Octane in my main tank and C16 in my stand alone. Other than this new addition any other ideas of making this setup more efficient?

gesto

1. Maybe take some weight out of the car.
2. Is your converter optimized for your nitrous set up?
3. Maybe have your stock LS2 intake ported or get a FAST?
4. Are you using the stock air filter box? Maybe an over-the-radiator air filter setup?
5. Could your 2.5" exhaust be a restriction?
6. What do your plugs look like after a nitrous run?
7. What size nitrous line are you using?
8. When's the last time you checked your solenoids for dimpling?

13qtr

Your goat is close to mine.. I got a fti 3800 triple disc convertor also. No cage,but weighs about 3900. Ls3 heads, btr cam, ported stock intake manifold, with the X-air otr intake.. and a 150 shot. Got 3.70 gears with a truetrac and 1000hp axles.My 4l60 has been built up pretty good. Best run has been a 10.67. with a 1.42 60' I run 15x10 welds with 26' MT pro radials. Good to see another fast goat....

Iron Indian

Not happening.

It is a 3800 Nitrous Converter from FTI. That could be switched over. Not sure if there is much gain there or not.

I've looked at doing a Fast. Not sure the gains will be there with stock heads?

Using a Vararam set up with a 4" coupler. It's SD tuned so no MAF.

I wondered that. Thinking about cutouts.

Timing strap looked in check last time I checked.

AN-4, what came with my Nitrous Outlet Kit.

Every season. Rebuilt them last season, plan on rebuilding them again before next season.

Iron Indian

What suspension do you have? If I could cut low 1.4s like you I'd be in the low 10s I bet.

13qtr

It's got the lowered King springs in the rear.....real damn stiff. Don't remember what shocks at the moment. I ordered another set of the stock bump stops and put them on the bottom. 2 bump stops per side/facing each other. Theirs only 1.75" between them, the car cant squat anymore than that. As stiff as the rear...they've never hit, as far as I can see. Also have subframe connectors and the so-called 'mini tub'. I run 15x10 welds with 26-10 mt pro radials. No way could I fit 28's under it....to low. NO air bags

gesto

I'll bet that stock LS2 intake is a noticeable restriction. A 6AN nitrous line might also help but I would check with Nitrous Outlet first. How much ET/mph do you pick up from a 125 shot to a 150 shot, and a 150 shot to a 175 shot?

Good point about the suspension.

Sounds like a nice GTO! Happy 2019!

Iron Indian

Very nice. I got 28x9 under mine however I'm Stock ride height.

Iron Indian

I've wondered how much if any the LS2 intake could be hurting. I know it's not the best flowing,

From what I understand there is not much to be gained from an AN-6 at this stage.

IIRC I was in the 10.7-10.8 on 150 and with 175 I went 10.5-10.6 after switching to a 28" (on 175 I ran out of gear on the previous 26". Never had that problem on the 150)

Happy 2019 to you as well.

98redorangeta

iTrader: (10)

Iron Indian

I'd like well into the 9s. I'll need another motor for that im sure. I'm certed for 10.00 now however my track is lax so I know I can push 9s.

As mentioned above, I do not want to spend money on heads on an old motor. I'd rather budget that with a better bottom end. Eventually she'll blow.

98redorangeta

iTrader: (10)

13qtr

you ran out of gear? with the 26" ? What kind of speed? I've trapped 130 at 6600rpms in 3rd with my 26". I've got the tune setup to lock the stall at 132...should be able to take it to about 145-150 in 3rd.

Iron Indian

I like a challenge. I plan to get there some day. It won't be on this motor though.

Iron Indian

It's been a year. IIRC I was turning around 6900-7000 in the limiter through the traps. I tried removing the limiter and Reving it past 7000 but it was about a tenth slower. With how it's setup now the car just doesn't make power past 6700-6800 anyway. I had the option of switch gears to say a 3.50 gear or do 28s. I needed tires anyway so that was the easiest thing to do. I was rewarded with faster times. I now go through the traps about 6500-6600. A 200 shot will probably put me in the same place again however. We'll see what happens.