LQ4 Build question WTF
Thread Starter
Teching In
Joined: Jul 2011
Posts: 21
Likes: 1
From: Charleston, SC
LQ4 Build question WTF I'm trying to figure out what my hp should be with my current setup. I've got a 2002 ws6 with the t56 and stock gears. the engine is a 1999 lq4 with dish pistons, 10k on the rebuild. 243s non-ported and milled 50k (stock thickness MLS gaskets), haven't done a compression test yet. LS6 intake with ported throttle body and smooth bellows connector. The camshaft is 242/248 duration 610/615 lift 114+2 LSA. New racetronix fuel pump and 50lb injectors. 1 and 7/8'' long tubes to 3'' y-pipe to Magnaflow muffler to dual 2 and 1/2'' outlets. no cats. Its been speed-density street tuned. I put it on the dyno the other day and it made 384 rwhp and 368 rwtq. Doesn't seem right to me 
Just wanted to see if anyone out there may be able to shed some light on this. All comments appreciated. Thanks.
Just wanted to see if anyone out there may be able to shed some light on this. All comments appreciated. Thanks. 
yeah that seems low if you have no clutch issues
IMHO that cam is pretty big for a stock 243 head without all the high rpm hardware to support it, your compression will be right about 11.35:1 if you milled the heads .050 to 55.6cc, if not your around 10.4-10.5:1
Personally i'd do some clean up on the 243 heads, run a different cam unless your planning on 7,000+rpm consistantly
a 234-240 at .050 .600 lift 112lsa plus 3* advanced 286-296 at .006 would work much better in a streetable rpm range with the parts you have, That Intake setup and your supporting parts don't make power where your trying to make it make power using a cam that big But Thats just my Opinion
I/you could get 450rwhp+ with the right combo
IMHO that cam is pretty big for a stock 243 head without all the high rpm hardware to support it, your compression will be right about 11.35:1 if you milled the heads .050 to 55.6cc, if not your around 10.4-10.5:1
Personally i'd do some clean up on the 243 heads, run a different cam unless your planning on 7,000+rpm consistantly
a 234-240 at .050 .600 lift 112lsa plus 3* advanced 286-296 at .006 would work much better in a streetable rpm range with the parts you have, That Intake setup and your supporting parts don't make power where your trying to make it make power using a cam that big But Thats just my Opinion
I/you could get 450rwhp+ with the right combo
Teching In
Joined: Nov 2010
Posts: 29
Likes: 0
That is about right for the combo of parts. I do agree that is a very large cam. The 243's are a good set of heads, but don't flow as well other stock heads with a good CNC porting job. With some good porting you can expect to be anywhere in the 420-450 range. Since the motor is stock displacement it will have a tough time making best use of that camshaft.
