Lin Gowan

Hey Guys
I have a 98 trans Am. It has been stroked, Headers, small cam, Moser rear end 3:91 gears. I am looking into Heads to get more HP any suggestions??
The car does 12.9's in the 1/4 looking to get into the 11's.
thanks for the advice...

Deeohgie69

iTrader: (3)

12.9's? What DA are you running at and what's your trap speed? Seems like something else is wrong that you may need to check into before you do your heads. LS1 or LS6 intake? And what size cam are you running? If it's a stalled auto then you should be well into the 11's the way it sits in decent DA. If it's an m6 then you should be bottom 12's in decent DA.

How much money are you looking to spend on heads? TSP has some decent budget heads and you can also send some 243's to advanced induction, they do some really nice work on them. Do you know how much power you made on your current setup?

Sorry for all of the questions, just trying to get a better idea to go off of.

Lin Gowan

Well I have always thought the same thing I will see if I can find the specs on the cam but its mild you wouldn't know it has a cam until you get on it idling it sounds pretty normal.

Anyway the manifold is stock. I believe MAF is after market and the throttle body but I believe it is still 72mm. I used to take it to a shop in AZ and get it dyno tuned but still its best run was a 12.8 and 12.9 being the most consistent number at around 108mph if I remember right.. And I guess that's why I would take it to them to dyno tune always thinking I should be quicker also those runs were with 4:10 gears I do not think the car has run on the 3:91
I changed the gears ratio because the car has the 6 speed manual and when I go down the track I either have to red line it to finish or try and hit 5th which takes to long once your that far so I was hoping the taller gears would solve that. SO if anyone thinks I should start some where else first besides the heads please let me know I would luv to be quicker the car is basically just a toy . BUt would like to run it again with some more speed
thanks

Lin Gowan

Sorry what DA?

HCI2000SS

iTrader: (2)

This has nothing to do with the gears. Something is very wrong with your ride if it's only trapping 108 with those mods.

Lin Gowan

Comp cam valve lift .522 intake .529 ex
Lift .265 .271

comp cam XR 265HR-14 Billet RLR cam

HCI2000SS

iTrader: (2)

I take it you bought the car as it is now? If so, this is an extremely miss match of parts, and I also wonder about the tune as well

murphinator

iTrader: (2)

this DA question needs to be answered to know how far off it is DA=Density Altitude) I see you mentioned Arizona so if your talking hot temps and high elevation track that will partially answer what is going on.

Bolt ons , gears ,cammed in reasonable racing weather you would expect high 10's to mid 11's depending on combo ,racing conditions and driver skill level. If your not on a good tire to race a 6 speed with (slick preferably stiffwall) that will slow it down due to poor 60 foot , you also don't mention suspension - anything there to help it hook up ?

Like HCI2000SS says above 108 trap speed for a cammed setup sounds way off until some of the other answers are provided to help explain why its not trapping 115-120 like you would expect , theres some bone stock 6 speed cars that have trapped within a mph or 2 of where you are currently on stock tires and paper filter.

What was your 60 foot time ?

What was your 1/8 mile time & trap speed?

What is the elevation of the track you race at?

What was the weather like especially temp.?

What tire are you on ?

Any suspension mods ?

murphinator

iTrader: (2)

I forgot you also said its stroked so it should be even quicker than my estimations , do you know how many cubes it is supposed to be ? compression ratio?

If it is indeed stroked and cammed but running a stock 98 ls1 intake and stock sized TB then that would be a big restriction holding you back as well.

Lin Gowan

I bought the car with headers and someone put some body supports other then that I have no idea. When I had it we blew a head hats when the rebuild started. yes all runs in AZ more then likely always in hot weather.
So I had the lower end rebuilt in Az that's when it was stroked and had the head re paired
we changed MAF sensor and throttle body and dyno tuned. I think everything else is stock that I am aware of .
As for racing I d ohave a straight pipe we had run when I raced. and drag radials.
Here are some times
T1 which I believe is the 60ft is 1.9 13.079 @ 107
yea most the time sheets show around 1.9 to 2

SO I think 1/8 mile is 83 to 86 mph 10 to 11 secs

Lin Gowan

I have one dyno sheet it shows eng torque average to be 277 to 296
HP which I had always found very strange is 211 to 219
max HP 284 max torque is 311

Lin Gowan

well then do you think I should start over with the upper engine mods and buy a kit to tie it all together ??
we have not mad any changes except clutch since 2008
and have not run the track since then also we are in Idaho now so would have to run in Boise which the air is going to be completely different

Lin Gowan

Eagle 4340 4.0 stroke LS1 crank
Probe Flat top pistons 1.050/3.902/.927/-3cc

HCI2000SS

iTrader: (2)

Honestly, I think you should start over here lol. Get the right HCI to support the cubes you have, along with the right supporting mods. This is the only way to have it perform the way it should

Lin Gowan

That's what I am thinking so any suggestions then what I should had change to make sure I am getting the correct things??

Think I should go run it up here to get some number then change things and run again or just get it to a shop re dyno then make changes??

Does my Dyno HP seem really low?? I always thought it should be close to 400 not 284 but I am not an expert so just wasn't sure

HCI2000SS

iTrader: (2)

I'd forget doing any track or dyno runs right now, since everything is so miss matched anyways. It's gonna dyno poor and run poor because its all wrong to begin with, so it really doesn't matter what it does now. With that said I'd start by calling some of the well known vendors on here. They will get into greater detail with you based on your budget and goals

Lin Gowan

sounds great thanks for the advice yea what sucks is I basically took it to the same speed shop all the time and heck raced with the guy who did most the work so I figured he would tell me what I needed since he did the dyno tunes and even we purchased the software to set the car up so I just followed what they told me.

Lin Gowan

New question I think it is fixed now and pretty sure its not related but anything is possible this car was also jinxed with clutches I have gone thru 4 clutches since I have had it and I am sure since I have owned this car I have only put 5k on it at most. With that said I have had a center force in it and 2 mcloeds each time they were changed it was like they had been installed wrong. Saying this also the Master cylinder and slave cylinder were changed several times trying to figure it out. Anyway I think it is back to a stock clutch now and I have not had any problem so far. DO you think this has just been clutches that did not match the car properly or crappy Mechanics. I mean I would blame my driving but honestly I do not drive the car very much at all ... Any thanks all has been great info

Lin Gowan

Have any suggestions which vendor would be best to start with ??
Summit ?? or someone else
I am not familiar with a lot of these vendors

HCI2000SS

iTrader: (2)

I went with Thompson Motorsports and am extremely happy. That's one suggestion