Just recently bought an LQ4/4L80E out of a 2001 GMC 2500HD 2WD truck. It has the 317 heads. The engine it will replace in my monte has about 325HP so I'd like more than the 300 the LQ4 is rated at. I want to stay NA on this engine.
The install won't be for another year or so, so I'll have time to start accumulating parts for the build.
I will probably go with a car intake/accessories but might not be right away.
Now for the questions....
1. How do I get to 400HP?
2. What does it take to get to 450-500?...future plans?

TIA,
Dean

 

http://www.hotrod.com/techarticles/e...ock/index.html

http://www.hotrod.com/techarticles/e...t_2/index.html

 

thanks for those links.

Anybody else have any buildups they would like to share?

 

here's one from carcraft, they went carb though
http://www.carcraft.com/projectbuild...ock/index.html

in the "part 2" for that one they switched cams and put on l92 heads and landed around 550 horses

 

Is your 350 325 HP at the flywheel?

Newer GM stuff is rated at the wheels in full street trim, so the 300HP LQ4 is probably more like 350HP at the flywheel.

A stock Lq4 with headers and some tuning / emissions delete should be capable of all but 400HP at the flywheel with no internal mods.

Correct me if I'm wrong here...

 

buy some stock LS3 heads and intake

 

@Jim PA

What constitutes "newer"? Just wondering, because wouldn't that mean that the '10 SS has 425 rwph (500 or so at the crank?)? That seems high. I may be misunderstanding what you said.

 

put a cam in it, done, seriously a cam, tune headers ect, and wallah 400+ hp at the tire.

 

You are wrong its flywheel hp with all accessories

 

Headers, thinner headgasket and/or mill them. (or trade someone with an ls6 that wants your 317s for boost) throw a cam in it, tune and bam. plenty 400hp cam only cars.

 

Right, I knew it was something like that.

But either way... his 325 HP 350 is probably 325 HP fully un-dressed, electric water pump, no alternator, etc....

If you did the same to an LQ4, it would probably put out at least 350.

All I'm trying to say is that a stock LQ4 may already be more powerful than his 325 HP 350.

 

I believe it was around 1971 that the factory started rating engines this way, but even when you read hot-rod or other dyno-related SBC articles, they are discussing Gross HP at the flywheel, completely undressed.

So... Sure, the '10 SS engine rated at pre '71 standards, or dressed down for a hot-rod article is probably going to put out 450, 460HP??

I'm probably wrong again

 

That 325HP is just a guess. It has Edelbrock performer rpm heads,comp roller rockers, comp cam, edelbrock performer airgap manifold,holley 750cfm,msd ignition,headers with dual exhaust......

 

So, LQ4 with headers, a tune and a cam swap (Z06 cam or aftermarket) that should give me a decent increase?

What about L92 heads and the required L76 intake...what kind of cam specs and hp for this setup?

Still learning about these ls engines......lots of info to sort through

 

You can mill the 317's .030 and port them and whola... you have 243's ported heads.....

Or you can do the L92 topend swap, but you must and I repeat nail the cam timing events down or you will have a dog.....90% of these guys picking or suggesting cams for these heads are just guessing out of their azz... Even the ones who claim they have spent thousands testing.....

I am not going to give you everything but I will tell you this, mill the L92's if you get them... your comp is already low now....9:6..... milling .030 should get you 10:1+ with a stock gasket

 

I know what you mean with the L92's...read a few builds and the low end torque drops but the power up top is higher....don't really care for a screamer, would prefer more bottom/mid power. This is after all a street car and not a racer.

I'll keep reading,

 

some of it is true... but the problem with these test and dyno's of L92 heads, most guys run splits that are too large....... which focus on topend power.....

check these out.....

https://ls1tech.com/forums/dynamomet...p-446rwtq.html

https://ls1tech.com/forums/13518728-post294.html

you can make 460HP+/450HP+ rear wheel power if you cam it right, which at the flywheel is 500HP+/500TQ+

 

thanks for that extra info. Now more reading

 

I have a lq4 with gibson tri-ys, true duals, Comp Cam .598 on 114lsa, milled 317s with stage 2 massage, and stock 8.1 injectors with a decent Nelson mail tune and it really screams. Rear wheel hp is somewhere at 400 or so. Does have full accessories and electric fans. Hope this helps. I believe if you do a L92 topend and a good cam to match you will have an awesome setup or go the ls3 way.

 

i have seen a couple LS2/L92 cars make 500 rwhp