Whitelightning32

iTrader: (1)

hello guys trying to get some input here. i do alot of street racing and trying to get some ideas of what my car is going to do and about how much hp it is going to have. the vehicle is going to get dynoed on a mustang dyno so no real numbers. The vehicle is a 01 trans am a4:

engine 5.3 lm7 around 9.0:1 compression if i figure it right
862 heads milled 5 thousandths
comp cams dual spring kit
comp cams 281 lsr cam
stock bottom end just freshend up 0 miles
fast 92 intake and tb
tsp 1 7/8 headers
o/r y pipe
slp lm1

flt lvl 4 4l60e trans
yank ss4000 stall
b&m trans cooler
chromoly driveshaft
stock 10 bolt for now with 3.73s

i was thinking the car should be around 420 to 450, havent really seen any vehicles with this setup so un sure how the vehicle is going to act. any input would be nice. the cars i run in town go to the drag strip alot and i know the times they run, just wanting to see if im going to compete.

thanks

NewOrleansLT1

While you had the engine out you should have bored it out to LS1 specs and maybe some 243 heads and you MIGHT have gotten those hp numbers you were hoping for.. But as it sits now your looking at about 360ish rwhp

Whitelightning32

iTrader: (1)

Is that on a dyno jet or a mustang dyno??

NewOrleansLT1

Don't get too caught up on dyno numbers.. Take it to the track and see if you can get the et. your looking for.. If not try and do some weight reduction, better heads, suspension, etc..

SteenH

That compression is really going to disappoint you. As said don't worry about the dyno number, usually a poor indication of the actual performance. Best of luck

SCott5

iTrader: (40)

360-370rwhp and plus he added weight of he iron block is going to slow you down a little more

Whitelightning32

iTrader: (1)

I've been doing a little weight reduction, I pulled the a/c and I'm going to be gutting the interior as well. I wanting the low compression for nitrous, I want to be able to run around a 200 shot through a plate kit eventually. I no numbers don't mean squat, I won't be disappointed by number cause I really don't care. One of my racer buddies runs 7.20s in the 1/8th on motor and was trying to compete with him

SCott5

iTrader: (40)

You will need the spray to run that time and you want higher compression with spray.

Whitelightning32

iTrader: (1)

Not necessarily, its safer and can run more spray on lower compression, the shop I work for builds 6/7 sec grudge bikes and that's all we build and the last alot longer and run alot better

speedtigger

iTrader: (16)

I thought the LM7 was 9.5:1? Why do you say 9:1?

Whitelightning32

iTrader: (1)

The heads were milled and the block was decked, after I got it out of the machine shop the Pistons were 14 thousandths outta the hole, so I had to get a .060 head gasket to get the proper clearance

speedtigger

iTrader: (16)

Unless you have modified the combustion chambers on the heads, here is what I get for compression for you based on what you have shared:




What you gave up in compression by running a .060" head gasket it appears you more than made up for by taking .005" off the heads and .008" off of the block.

Whitelightning32

iTrader: (1)

Got ya even with the flat top pistons? That's nice to know though I appreciate it. All the numbers look right

speedtigger

iTrader: (16)

Do you have flat top pistons or stock LM7 dish pistons?

Whitelightning32

iTrader: (1)

My lm7 has flat tops in it there stock...

speedtigger

iTrader: (16)

Those in the picture are actually what most of us refer to as dished pistons. See how the perimeter is higher creating an area in the center that is slightly dished?

Here is a picture of an LS with a true flat-top piston:

Whitelightning32

iTrader: (1)

I thought they were like -3 flat tops but I could be wrong

Whitelightning32

iTrader: (1)

So with that being said about 9.5 to 1 you have a idea about tracktimes u think it would run. 15s and mt radials.