Agree that was a pretty dumb statement, I'm not one to ever blindly trust a sensor because I've seen them wrong too many times. Even with multiple widebands and EGT sensors I'd still check the plugs, can never have too much input as to what the engine is doing.

 

Roughly 10cc in chamber volume, almost a full point in my case. I threw 317's in trash, went back to 862's gained 5 MPH with no other changes and on same boost level.

That's why I never went back to low compression.

 

That's a heck of a bang for the buck gain.

 

And here I am at 9.5scr area

 

That just means you have more cushion for the pushin

 

Agree, I was shocked too and price was almost free. When the 11:1 engine went almost 150 on 9lbs just backs it up further. Guess we can go full circle to that doubling NA power discussion.

 

That was a decent topic I was just talking to a friend about the other day. It really is interesting especially when comparing turbos and *gasp* if they actually have a compressor map

 

its making around that, went 4.29@168 at 2450lbs

 

Nice that's moving out. I wish I could cut 1500 lbs

 

The compression things always a trade off. Your just trading response for more power making potential. Think most are at he point where they know the more you make NA the more you make in boost. But the 4-6% rule is pretty standard per point of compression. Which is then compounded with boost. So if 1 point of compression picked up 5mph at the same boost... what happens when you run 5 more pounds of boost instead with the 317's? Why is one better than another? Which will make more assuming your not turbo limited?

You'll have less peaky combustion spikes with lower compression and an easier time keeping the heads sealed if you really lean on it. A lot of that is in the tune, but tuning around peaky cylinder pressures isn't ideal either. Its been proven MANY times with the methanol guys running big boost. There's a point where it just makes sense to drop compression to keep the heads down. Where that is will depend on the application. There's a reason top fuel runs 6.5:1 compression ratios.

Low compression gets a bad wrap because its crap for spooling turbos and you need a larger power adder to do the same work. You also have to look at the lady finger VS M80 theory. A bigger CC is ultimately better and will allow more power... If you can reach your "goal" without stupid low compression and giant turbo(s) that's a bonus. Zero reason to go crazy in either direction IMO. I prefer to have just enough to get into boost quickly on the 2-step/brake. Once the turbo is making target launch boost... it didn't really matter in my experience. 8.6:1 VS 10:1 could net the same times by varying the boost levels. I'll say as a personal preference, I hate the sound of a doggy compression LS vs a nice crisp raspy 10:1+ I don't see any reason to be under 10:1 on an e85 build SBE either. I just like to stir up discussion.

If I were building a Bonneville car and wanted a stupid amount of power and response isn't a concern, I'd go with a "low compression" setup. Its just easier on parts all around IMO.

 

Aside from the guy telling us not to bother looking at plugs... He's completely wrong about fueling VS spark advance as well.

There is a peak power range AFR for every fuel. IE run it on a load dyno at a fixed load. And adjust the timing and fuel for peak power at that load. He never mentions actual numbers... But sounds like his method of tuning is throwing too much fuel at tune then advancing timing (beyond MBT) to burn excessive amounts of fuel. This will result in higher cylinder pressures and less power. Its a great way to blow a head gasket. Going beyond peak power window of a fuel just to have more fuel in the cylinder does nothing for power. The guy's a half wit IMO.

Here's a great explanation as to why he's full of it...

https://www.innovatemotorsports.com/resources/myths.php

 

Bold is exactly the point. I believe you also have commented in the past that anything beyond XXX whp on the street is useless as its too difficult to hook up. So why not sacrifice some peak power for something more responsive and fun to drive?

 

Couldn't run anymore boost, turbo only wanted to make 37lbs. Plus the car with more compression will stage faster, have a better power curve, and all around be a better driver. Really is no downfall as long as your fuel can support it, and E85 seems to love compression.

 

Stop with your reason, drive top fuel cars on the street

 

I did and its awesome

 

I’d be better off building a purpose built car than destroying my low mileage GTO to try and remove 1000 lbs let alone 1500.

I haven’t ruled that option out yet although the wife would accept me putting a torque arm or 4 link in this irs car before she would let me start another project. A 315/60/15 and anti squat would be a big improvement over my 275/50/15 squatting irs even at the same weight.

ETA: I’ll still be staying with procharger no matter what I do though lol.

 

Quotes Viki from I Robot...."My logic is undeniable"

 

Ya I changed cars and decided to tear that one apart as well. Mine was low mileage as well, but I dont care as I dont value cars as investments. I looked into torque arm vs 4 link and 4 link seems like the way to go.

 

I think everyone here knows what we do isn’t an investment financially. It’s an investment in happiness...lol

The 4 link is definitely superior for what I want to do, but moser makes an all inclusive 9” torque arm kit for the GTO so it’s the easier conversion.

 

Ya moser makes one for mine too but its like $7,500. Overpriced to me for a couple bars that arent hard to make, you can do it for half that and have it turn out even lighter.