yellowzron

this is all new to me and still trying to figure it out. My car is a 10 gs 24k on it, AA si, kooks headers, tune, fast intake, E85, 1300 injectors, and small other stuff. I am currently making 702 to the wheels on a dynojet on 9-9.5lbs of boost. The question is, if I go down to a 3.6 what gains should I expect? I was wondering if anyone has done similar modes and what they are making on a 3.6 or a 3.4. If I go down to a 3.6 should I see at least a 1lb of boost increase, and is that worth it. Should the 3.6 bump me up at least 25-35 rwhp? I am asking because this is all new to me. Had an 07 with 550 hp and dropped a valve so now I wanted to go to an LS3 and boost it.

The car runs great, no issues runs perfectly and love it. Was just seeing if I could bump the power up a bit. On the aa si, with no e85 I ran a best of 10.79 at 130. Also I am still on the stock clutch

Tech

Down from a 3.8"? You didn't mention what pulley you have now. Dropping one pulley size isn't going to make much of a difference in SOTP. FWIW, 3.4" might be over spinning the Si unless you've lowered your redline.

g23crawler

Any engine mods(springs, push rods etc)? If you are already making 700 at the wheels that's around 830 crank hp. Ls3's love boost but you may look into a better valve train before pushing it much further. What fuel system do you have? That could be a limiting factor too, personally I would do a cam kit. That would give you a nice 60hp or more bump.

JetstreamGS

I'd go straight to a 3.4 on corn. Those are strong #'s as is. Do you have a cam?

xBoostx

If I say is what I would do yes you can make more power with stock block but for how long problem is the stock pistons so I would enjoy it as it is and start a forge project for the future when that project is ready swap block and go for it.

You mention stock clutch include a zr1 or better upgrade with your next project. IMO.

yellowzron

I have a 3.8 right now.

yellowzron

Im sorry I forgot to add I have a speed Inc SI9 cam dont remember the specs.

yellowzron

The speed shop did dual valve spring hardened pushrods and a speed inc SI9 cam. Its a cam for a blower. I have to look at the paperwork to see what the specs are.

Unreal

700rwhp is already close or maxing out the Si. Better off putting a larger blower on. Smaller pulley may not add much of anything, as blower is already giving it all she has, and will just turn it into a belt slipping heat pump.

JetstreamGS

A 3.8" isn't even close to maxing it out. Hell, he can go down to a 3.4" and it still wouldn't be maxed out shifting at 6500.

yellowzron

I am shifting right at 6500. I was just wondering if anyone has had a similar set up, then gone from a 3.8 to a 3.4, and what gains did they see.
Or what gains I should expect ?

JetstreamGS

I'd be really curious to see what a maxed out Si would make on a E85 build. With a 3.4, I'd bet she would make over 750rw considering you're over 700 now.

Patriot Six

You would probably pick up about 4 psi and 80 or so whp with just the pulley swap, but would be close to maxing out the blower and possible belt slip on a 6 rib.

LSX228R

I'd honestly just leave it alone lol. Put money aside in case you need a clutch.

C U IN REARVEIW

Is a 3.4" on a 6 rib asking for belt slip? Im about to do this on my ti-trim blower setup

Patriot Six

Once the belt stretched, I had belt slip on my Ti trim with 3.4 and stock LS7 balancer. I have a secondary drive now and more boost with no slip.

C U IN REARVEIW

Stock tensioner?

Patriot Six

Yes, I could have played with adjusting it regularly, but went with the secondary drive and picked up 2 pounds of boost.

Unreal

Max impeller speed and max air the blower will move are two different things. Better off putting the money/time into clutch/etc, and saving up for a bigger blower if you want more than 700rwhp. You get to a point where spinning it hard gets very small gains, and on a big motor, your probably already riding the edge of the compressor map.

C U IN REARVEIW

This build has spiraled out of control financially.....the A&A tensioner solid enough to hold tension if regularly monitored for awhile? Or am I looking at for sure issues?
Stock Ls2 balancer and 3.4" pulley....