Meen95z

I have a hardtop 95' Trans Am and seems to run slow for my mods.. Anyone have some experience or info that could help me out.. My car is a rebuilt 355, forged pistons, 11.1 compression, lt4 heads w/beehive springs and intake, 58mm tb, cc306 cam, 1.6 pro mag rr's nsa, longtubes, 3in xpipe, 2800 vigilante stall, 4.11's in 9", elect. waterpump, cai, mass air meter, digital 6 plus, msd 8.5mm wires, 160 stat, tr6 plugs, pcm4less tune and lt1 edit, 30lb injectors, qa1's up front, lower control arms and relocation brackets, a/c delete, nitrous works kit.. And this car will only go (373 and 10 bolt) 12.60@ 109 w/ 1.79 60ft.. Havent ran with the 411's and 9" yet, but shouldnt be faster than a 12.60 on motor? This shifts at 6400 on the tach.. Any info would help...

greenmachinedriver

try a real dyno tune. i had a pcm for less tune and it really never made much power and it was way rich. also the dyno will give you more info about hp numbers.

GreasyB

Maybe the 3'' x pipe is too much flow for that engine.

brubaker

Are the lt4 heads still as cast or have they been ported at all? also I think brian tunes them more on the rich side so people arn't melting pistons and blaming him!

96capricemgr

The LT4s were a poor choice, the 306 was a poor choice, the MAF that sounds like you "upgraded" was probably a poor choice, 2800stall is too low. Had a number of problems with pcmforless myself.
Compression could be higher.

Meen95z

Well they have alittle port work, just bowls worked and runners opened up alittle along with the intake.. It dynoed 347 rwhp 331 rwtq n/a.. And now that you told me my heads, cam, and everything else is a poor choice, what other cam do you suggest? And would a 3600 stall help any?

BigBadBlack93Z

Yes, an increased stall speed and a higher RPM range would be bandaids for the combo.
You could either got w/ another cam and keep the major components the same (not really improving much on the output though) or have more head work done to let the cam breathe better and up the stall and shift rpm.
Your budget will dictate how to attack it. cheapest route is take it to a local tuner and put it on the rollers to verify you have a good tune in it and then make your decision.

Meen95z

Well I have another motor about done thats my race motor, this I have had for about 2 or so years just want to get it moving alittle faster for this summer until my better motor is done... I havent ran with my 4.11's yet, would a 2800 to a 3600 help out enough with the 4.11's to get me say 12.30's n/a? Im not gonna spend anymore money on these heads cause I have a actually good pair in the shop..

BigBadBlack93Z

if thats the case i would spend the $200 on a retune before $600 on a stall unless you have a deal worked out already. If you can find another 15-20 hp and hook you should be able to run the number.

Meen95z

I can get the stall upgrade for $225.. A dynotune around here is like $500.. I could always get a stock set of heads and a intake and put a 503 cam or leave the 306 in it? How streetable is your 3600 stall?

Bersaglieri

"poor choices"

You shouldnt have any problem cracking off low 12's and possibly 11's with them. You've definately got the potential. Dont let internet people talk you into throwing parts and money at a car that already has plenty of power mods. The most important thing to get better in the 1/4 is seat time. Although, you are definately pointed in the right direction with suspension mods, power mods, and compression.

First - Make sure your tires are up to the task, if they arent the 4.11's are only going to make things worse. Traction is going to be your best bet trying to get better ET's. You should be working on getting your 60' down.

Second - After traction has been solved you may want to get a bit higher stall. 2800 is too low for a heads and cam car in my opinion. Get a restall to at least 3200. 3200 stall, 4.11's and traction should get you a nasty hole shot

Next work on tuning and figuring out little bugs in your combo. You should be trapping higher than 109 with just a CC306. Either your track and weather conditions arent helping or you've got some bugs to work out. You'd be amazed at how attention to detail and solving a few small things can bring a car alive. Guy's like Javier didnt get good track times from throwing parts at their cars, it was from seat time and making what they had work. Perhaps you need a better tune or the aftermarket MAF is screwing things up, valvetrain geometry, or fill-in the blank. Your combo is probably going to need some more RPM's to run a bit better too...consider that.

Keep your head up and work with what you've got. I wouldnt be worried about a "race motor" unless it's got a radical cam or solid roller with full ported aftermarket castings and big cubes.

I might just have to run with "old out of date" CC306 I have and "crappy" LT4 heads of mine to show some folks you dont have to have name brand CNC stuff to have a good running car. Off the top of my head...I know of one car with a CC306 that went 9's with some spray, another that ran it cam only on street tires and trapped 115mph, another that ran it cam only with a drag setup car and ran 11's trapping in the 116-117 area, one that ran it with ported LT4's that dyno'd in the 430's with a 9" and automatic...the list goes on.

Good Luck.

-Dustin-

Meen95z

Well I think I'll go with what you have to say.. I'll work on the traction and getting a nasty hole shot then work on the tune some more.. Like I said this motor I have is gonna be replaced with a new motor next year, but need to make it run alittle quicker in the mean time.. Thanks again Dustin..

BlkLT1Z28

That to me is problem #1. Its a 306, it needs at least 6700~6800. When my car had lt4's and an 847 it ran the best times when I pulled the tach to almost 7k.

The stall needs to be higher, but people have covered that already.

I personally thing 3.73's would be a better choice then the 4.10's but thats just my opionion.

If you still got it, put your stock MAF sensor back in. They seem to be much better at doing there job then an aftermarket one.

How many miles are on this motor? It sounds pretty fresh.....give it some time to really break in. It will pick up a couple mph.


Your car can run better with what its got. Just need to figure out how to get it there. And like Dustin said, you need seat time at the track.....you need to learn what your car likes and what it doesnt like.

Opionions are like *** holes.......everyones got 'em.

slomarao

like said before, rev it up to 68,6900 rpms. Thats where that 306 is going to shine. Second get rid of the aftermarket maf, go back to the stock one. If you dont have it anymore than buy one used. too many people f with their maf and all or their cars are never running right. Last would be a real dyno tune. You need to know whats going on with your tuning if you ever want to get some decent numbers out of it.
After all that you should be 385rwhp or near it.
The stall is a bit small but its only going to make a difference on the track. (well it has affect on dyno numbers but its small)
The heads need some more work if you want bigger numbers. Send them to le or ai and pick up a custom cam. 425rwhp here you come.

Meen95z

Would lt4 heads flow over 6500 rpms? And my motor was rebuilt and balanced how will that hold up? And im gonna get a 3200-3600 stall soon im thinking.. Also I have a ported stock maf, is that any good to use since I had it tuned for a aftermarket maf?