Jimmy P

iTrader: (177)

Here is the story. I bought a 99 SS that was modded, and the previous owner told me it had Absolute Speed stage 2 heads/a 224/224 cam, a 3600/3800 vigilante cam, ls6 intake, mac mid leanths with off-road pipe, and a few simple bolt ones. Well the trans was giving me overheating problems all the time. It would blow trans after trans, and now I got a FLP stage 3 trans that has held up, but was still overheating. Two different shops told me that the pcm was bad and they couldn't access the trans settings on the pcm, so I finally got it changed and dyno tuned to my mods by the local shop. Since I have had it, the car has gotten a new trans, a Yank SS4000 converter, yella terra rocker arms, the new pcm was dyno tuned. Well, it only dynoed 340rwhp and I know the shop isn't at fault, because they do good work. But how do I find whats wrong with the car? Maybe the previous owner was lying about the heads just so I can buy his car, but the car is deffinantly cammed, you can hear it. I have also installed a moser 12 bolt, which I know will make u loose a few hp, and the beefed up trans probably has heavier components that might rob hp, and I dont have long tubes, but 340 with all those modifications? Me and my buddy installed the yella terra rockers when a stock rocker arm blew, so maybe we didn't install them right? The shop said that there was a slight coolant leak, but it wasn't getting in the motor. Can anyone point me towards the right direction of what to do? 340rwhp from a car with these mods is a joke. I was thinking somewhere in the range of 380 or more. I do understand that a loose converter like a Yank will make you show a lot less hp, but can it be that bad? I am thinking of selling the car buying a nother LS1...Or keep it and add a procharger or go with a different heads/cam kit. What do you guys think? I realy like the car, but 340 at the wheels is....

CrazytrainWS6

thats definitely messed up. how many miles are on it? you could always drop a new engine in it. a 427 would be fun.

xfactor_pitbulls

iTrader: (16)

Well the fact that you dont have headers pretty much means the extra flow you are gaining from the heads and bigger cam are probably bottle necking at the exhaust port. One would like to expect that would free up 25rwhp or so. You also have a good sized stall which is soaking up power. You didnt mention what the torque numbers were. I would assume alot higher then HP. What were the conditions when it was tuned? What was the A/F. Where was the timing set?

Brandon

GREATWHITE

Also, what kind of dyno was it??

hourang

iTrader: (6)

i agree, not having long tubes is killing you, my buddy dynod in the 340rwhp range(mustang dyno, m6 car) with heads and cam without longtubes or ls6 intake. with the addition of long tubes, ls6 intake and exhaust it shot up to the 380rwhp range. so 40rwhp. so i would STRONGLY advise on getting long tubes, and also junk that flowmaster, throw a cutout on or better muffler, that in itself will net 10-15rwhp. as for the tranny problems, you do have a separate tranny cooler right?? good luck.

Jimmy P

iTrader: (177)

It was on a dynojet. The motor is prety new. The block was purchased from Speed Inc and the previous owner of the car sayed its been in the car for less than 5,000 miles...I got the car back today, and I guess the new pcm has resolved the trans heating problems. I didn't drive my car for over a month, so when I got it back, I was driving it somewhat hard, and after 1 hour, the trans finaly reached 183 degrees. Then by the second hour of driving, it crept up to 194 degrees, then went down to 189, and stayed there. I do have a B&M 24,000 trans cooler on it, but I will be installing a Derale 25,000 fan mounted cooler soon, just need some free time to figure out were to mount it. The fan activates when the trans temp reaches 180, then stops when the temp drops below that.
A total new exaust will be done, its just a matter of when. I want long tube headers, and a true dual exaust, no cats offcourse. I will be gong to Speed Inc to get it done , as I have heard their stainless true duals are real nice.
I guess since the trans issue has been resolved, I will just keep the car, even though it dynoed realy low. I guess if I have enough money in a couple of months, I will try a different head/cam kit. Or I can keep the current cam, get rid of the 5.3 heads, and put a procharger on it.

P Mack

iTrader: (6)

You could always pull the intake and take a look inside the intake ports, see if they look ported.

Strahley

iTrader: (4)

If you are struggling making power with a heads/cam combo, I doubt throwing a supercharger on it is the correct answer

jonnyc

iTrader: (18)

definately do long tubes and ls6 intake.if you ever change the heads or cam you'll need them anyway or you'll be in the same boat you're already in.lt's and intake should get you atleast 30rwhp if you do have heads/cam.

Jimmy P

iTrader: (177)

So your saying that theres a problem with the car that I need to find first?

Oh yea, the car has an LS6 intake manifold.

wes96z

iTrader: (1)

damn! I dynoed 345hp 350 trq on a dynojet in arizona when it was 90 outside and all i have for mods is qtp lt's no cats w/a 2.5 x pipe and a lid

Jimmy P

iTrader: (177)

Was that a on a m6 or a4? After thinking about it..I have come to these conclusions. The car most likely does not have heads on them. I spoke to someone who knew the previous owner, and he was hinting that the car didn't have heads. I guess I might as well save up for some heads, long tubes, true duals, and possibly a different cam, ASP pulley and see what the car can realy do.

hourang

iTrader: (6)

you should be able to tell by the casting number on the heads, if its 853 then its stock heads. for now i would concentrate on getting long tubes and exhaust then a retune. after everything is set you should see around 370-390 rwhp, after that then decide if you want new heads and cam. good luck

16nrollininaws6

Yeah, I think the previous owner was full of ****. 340 rwhp with those mods is HORRIBLE, even without LT's. You do have Midlengths, so the exhaust isnt that bottlenecked. I would say you have an absolute dog of a car or you dont have heads. Hopefully the second. Look for the casting number to confirm it.

demonspeed

iTrader: (7)

I still think the numbers aren't that great even for a cam only car. Take it to the track and see what it runs.

Jimmy P

iTrader: (177)

Were can I find the casting numbers on the heads? Id rather just do the heads/cam swap at the same time that I do the longtubes/true duals. That way I am only paying for the dyno-tuning just 1 time. Do you guys recommend the AFR 205 cc heads? I think they go for about $2200.

JZ'sTA

iTrader: (23)

The AFR's are real nice.

Jimmy P

iTrader: (177)

Do they give me more compression? They aren't listed as 5.3's, so probably not, right? It would be nice if I can get around 390rwhp with a new set the AFR 205's and a nice sized cam.

P Mack

iTrader: (6)

Unmilled AFR's have the same compression as stock. I bet if you wait for a christmas sale or something you could get them pretty cheap. You could've got them from Thunder Racing for 2025 when they had their 10% off Thunder countdown sale.

Brandon Boomhauer

iTrader: (10)

whats the castin # going to help, they may be ported stockers....
or does every head porter grind the # off??

did i miss something here?