• 383
• Forged internals
• LE2 heads and cam
• 11.5:1 Compression

~for more specific mods see cardomain link below.

I know that you should decide what you're going to do from the begining of a build up. I originally built this engine for nitrous. Since then I've got a new job, I'm making more money, and I've kind of shifted towards the idea of forced induction. How much boost can I put on an engine with 11.5:1 compression? I'm guessing around 4psi... 6psi tops.

I'm making around 420whp or so now... how much more would 4psi get me?

Thanks

 

would be a waste of money... get new heads or new pistons.

 

you could, but itd be a straight race gas motor... agree with the above statement

 

Oh well... I'm not pulling the motor again. Looks like I'll have to stick with the bottle.

Thanks

 

You can't, too much. Get another head gasket and stack them to bring it down, you need it under 10.5:1 at least.... Then you could run it at about 6 pounds or so. Even 4 pounds is too much for 11.5:1.

You said you didn't want to pull the motor again but that's exactly what you'll be doing if you try to charge it!

I'd make the necessary fixes so you can get that baby blown. You'd be making 500-550 with 6 pounds.

 

Probably be easiest to put another set of heads on there. Have them worked to get the compression down as low as possible. Like everyone else said, boosting that high of CR is asking for trouble.

Ken R.

 

No.

Rich

 

^Werd...juice it till it blows, and then go FI

 

WERD!

 

Just spray the motor and be done with it.

 

put some AFRS on there..arent they 72 or 76cc heads? that will drop the CR down enough.

 

I agree. That is what I'm doing.

A while ago I was in the same position. I was thinking about boosting my motor which has the identical compression. It's no good. If your all forged up, spray it. I'm not completly forged but I'm well rebuilt. I plan on spraying mine with an HSW 125 wet kit. Hoping for about 500rwhp on the bottle.

 

You "can" run high boost with high compression on pump gas..you'll have to
run an alcohol injection kit...
my buddy was running his GN... stock internals..25lbs boost at 25 degs on pump gas with the alkycontrol.com kit..and that convinced me!

I'm running an LT1 11.00 to 1 ..with 21 psi at 19 degrees on 50/50 pump gas and C-16 with the alkycontrol.com kit on methanol/water(70/30)..
I'm still working on the tune and slowly going to all pump gas while watching for knock and reading the plugs..

the kit is wicked!..it's progressive..working off fthe MAP input..

I'm pulling the trick-flow heads off this week to get a port job done to maximise for boost..

Matt

 

Much as I am a fan of WATER injection, or for that matter ater/alcohol injection, an 11:1 motor with 21psi will detonate on pump gas. With a good set of pistons, etc. it may last a while, But I am sorry to say it won't be all that long if you run it hard.

Rich

 

I ran a 450 shot on a regular basis..raced in the NMCA/NSCA etc regularly
for several years..fully forged..built for abuse..
I didn't switch to this set-up without alot of info..
according to some tuning buddies..folks are 'building' high compression
blower/turbo motors for alcohol kits like these..my buddy Dave Cain in Florida
says it's the newest wave..he's tuning pump gas 30 psi motors on isopropyl
alcohol with these kits..
an NMRA buddy of mine is building a blown mod motor to run 30 psi
with this kit...
You better go checkout the turbo buick guys and the mustang boards..
they are usually on the cutting edge of boosted applications..
If you don't believe..just wait till one of those guys pulls along side!..LOL

I thought I'd just pass it along here.

See ya on da Power Tour!
Later,
Matt