High Compression VS Low Compression Opinions

[jasjamz]

I don't understand why someone with an 11 to 1 engine would run the same spark timing as a guy with 9 to 1. Just for shits? Not matter how low or high it was.

Do you start tuning a new build at 25-30 psi?
Do you make your 1st pass at 27*of timing?
I don't know what makes you think Im saying strap them all to the dyno at 30 psi and 26* of timing and lets see what happens because its not.

 

[No disintegrations]

I'm not saying 26 degrees and I'm not saying 13 degrees. But they all want something different so the tumer would give them what they want and not try to restrain one or break another. Not meaning this to sound like a dick. Hope you understand what I'm trying to say.

 

[jasjamz]

Sure, I completely understand and know what you're saying. Its just the fear on this board to try and learn something outside the box it what is killing off these cars. The envelope has to be pushed. You learn from the good and bad...

 

[rag231]

I think that with some of the great hard parts that are on the markets now, forged rotating assemblies, electronics, boost controllers and great cylinder heads, now is one of the best time ever to think and experiment outside the box. Before, my mental limit to pushing the 109 motor were the crank and rods, now I don't "feel" like there is a mechanical limit and that it's all in the tune.

 

[bison]

A question just for fun. If both cars were at the track running heads up. Would he put you on the trailer or could you tune around the disadvantage of lower compression?

He wouldn't put me on the trailer because I never trailered that car anywhere for one. Second I've got several hundred Dyno hits thousands of quick street hits, hundreds of hours of drive time in the street and way more suspension upgrades like better shocks, better rims and tires, car is about 300lbs less race weight, etc. I've already proven what the car can run with way less cool guy stuff and less power. He'd be making a lot more power but be noticeably slower. If we were to do nothing but take his engine and put it in my black car and let it eat it would be very bottom 9's.


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Running with about the same power or slightly less I trapped 135+ and got his car to trap 130mph and about 7 tenths slower and couldn’t apply any real power till about 100’ out or we had a lot of wheel spin.


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[bison]

I will stay in the 9.xx range and crank up the boost. I have recently learned the prices of built 109 short blocks are a bit more expensive than they use to be.

I know this is old school, however Red Armstrong use to say he only wanted enough compression to be able for the engine to crank. He would make up the power with boost. Richard Clark somewhat believes the same.

With that train of thought you will be left in the dust if you’re serious about being competitive. The engine will be inefficient and the car will be an absolute turd out of the hole where it really needs to shine.


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[1952ray]

With that train of thought you will be left in the dust if you’re serious about being competitive. The engine will be inefficient and the car will be an absolute turd out of the hole where it really needs to shine.


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Don’t disagree with your statement, just repeating what I’ve hread others say.

 

[Mike T]

1952ray you must have made your grandson very happy! "1987 GN 11,670 miles, bone stock. Given to oldest grandson"

 

[1952ray]

1952ray you must have made your grandson very happy! "1987 GN 11,670 miles, bone stock. Given to oldest grandson"

He has not made me happy, he has destroyed that car, has run in to every ditch bank he could find, had wide critters run out in front of him, the trans will not come out of second gear, and the motor has been hurt. The few times I have seen my daughter he is no where to be found. Won’t face me, a pure shame. They live 400 miles away from me. Big time mistake on my part. Still living and learning.

 

[Mike T]

That's a shame. Looking back my brain didn't start to develop until about 23 and progression has been slow since then..........did a lot of dumb stuff too

 

[1952ray]

That's a shame. Looking back my brain didn't start to develop until about 23 and progression has been slow since then..........did a lot of dumb stuff too

Yea I hear you Mike, but this is just plum crazy. I need to take it out of my sig.

 

[87GN_Bart]

You are a good grand father don't change because one kid just doesn't appreciate what you did for him.

 

[1952ray]

You are a good grand father don't change because one kid just doesn't appreciate what you did for him.

There isn’t any changes, just big time disappointment that he leaves town anytime I come. Going to show up unannounced to solve this BS. I mean he’s 22years old.

 

[Mike T]

Running with about the same power or slightly less I trapped 135+ and got his car to trap 130mph and about 7 tenths slower and couldn’t apply any real power till about 100’ out or we had a lot of wheel spin.


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My compression is in the mid to lower 8.0 range. Big turbo so it has taken a lot of brake, tire and suspension upgrades to finally get it to leave at 10 psi on the street. Trying to sort a few things before going back to the track. I will admit that it still did not leave nearly as hard as was expected. Hooked at 10-12 psi and I suspect low power was the reason. However 1 degree advance did wake it up a little so timing could be a part of the problem.