http://www.ls1tech.com/forums/showth...t=single+plane

automotivebreath: my bad.

 

Thanks for that link Mike; you have an opinion on chrism400's rich A/F with the single plane?

 

Is it tuned in MAF or SD mode? How close is the MAF to being max'd out? Where is the FPR referenced to?

Mike

 

Are these engines CAMMED for a single plane? Also a super vic on stock head castings seems to be a mismatch, wouldn't a victor jr be a better choice?

Seems like a super vic would be a better match for a 220 cc or bigger runner.

David

 

David, Chris said it was a Team G, that should be a good intke for a stock head engine.

 

There is a lot of power in different castings, even from the same family of intakes. All depends on the motor under them really. Part of them is how well you can tune them.

Bret

 

It was my car that Engineermike is referring to. It is a 383, Comp Cams 25x/26x ~.650 lift solid roller on a 112lsa. Heads are Comp ported AFR 220's. There was a lot of time and effort put into the intake. I won't rehash everything I've said in previous posts about the switch, but I went all out and used all good parts and basically did it as nice as it could be done, having much of the work done at Thunder Racing. As the graph in the link shows, there wasn't any gain until after 6000rpm. There have been over 40 dyno runs with this intake to get tuning spot on and Thunder does some of the best tuning out there.

My ultimate conclusion is the swap isn't worth it unless you are spinning OVER 7000rpm. If I could do it over again, I'd keep the LT4 intake/monoblade and put my money elsewhere, ESPECIALLY for a street/strip setup that isn't a dedicated racecar.

 

Had some questions about the graph


Why the difference in the A/F?? The lt1 intake made its most power in a leaner condition than the single plane?? I've heard that you shoot for a 13.0 A/F N/A, then add fuel till it starts loosing power. So you were making close to the same power with more fuel?


I read another post about heat soak on the lt1 intake.

From my own experience once the intake its hot, she is down on power a little, afg's dont read as high on the top end. How does the single plane with the carbon fiber lifter tray, help out? I've heard some, but nothing first hand. The ls1's dont seem to have the heat soak that we do.. Just wondering

What was your total timing set at??

B-rad

 

Wow, there is alot of good info in that graph. That's a 383 with 220 heads and the stock intake is feeding it just fine until about 6500. Even with its short runners, torque is better with the stock one too down low. In this case, it does appear that to utilize the extra power up top, it will need to be spun much higher. The a/f question posted above is one I would like to know as well. I wonder what the 20 hp dip at 6300 was with the stock intake. If not for that, the LT4 intake was really working well.

So, in review...A ported/converted single plane with over 40 dyno pulls barely beat a stock LT4 intake with monoblade up to 6500 in a 383 with a 220 runner head. Geez, 40 pulls with the LT4/monoblade would have made better power too. Thanks for the info. I've seen all I need to see here. Yeah, the new intake makes 45 more hp but at 7100.

This converted Team G intake properly tuned should end up beating the stock one pretty much everywhere given the fact that it's a low rise smaller runner intake than the one used above. It looks like it may be the right choice under 7200 rpm. Numbers just aren't going to be that much different though. I wonder if it's going to be worth the time and hassle. To me, it wouldn't be.

 

Heat soak is one big advantage of the intake, on back to back to back runs, it will lose maybe 3-5rwhp max and doesn't heat soak. It also has a lifter valley pan deflector to keep oil off of the underside of the intake.

As far as the AF ratio, I don't know for sure, but leaning it out further didn't make any more power and the car liked it best where it's at. I don't know if this has something to do with better/more even distribution over the LT1 intake, but I would assume so.

BTW, if anyone is interested in a max effort, no expense spared setup, I may be selling the car.

 

Turbo6,

Thanks for the information; that’s not at all what I would expect from that swap on a good engine like yours. It says a lot for the LT4 intake and tune that was on it before.

I'm interested in what was done to re-tune it after the swap. Was much work required to compensate for the improved air flow to the rear cylinders?

Chris,
From the swap at the beginning of this thread; can you answer these questions for Mike?

 

Yes, I can answer a little bit. It is a MAF car with a ported 3 inch MAF. The fpr answer I don't have. Where should it be on the intake?

 

I should have some kind of comparison here shortly. I swapped from a ported/welded lt4 intake to a Accel pro ram with top mount throttle body. It has slightly shorter runners so it may not give up so much down low. I'm also going to be spinning to 7400 but my lt4 intake did that before the change. Only problem with a back to back comparison is that I rebuilt the bottom end and changed the cam slightly. But we should still be able to see how its gonna act. we will see shortly.

 

Here's a couple of AIs setups using their ported LT1 intake manifold and 200cc heads. Bigger isn't always better:

Both numbers on stock PCMs.

355: 480/419






383: 517/494

 

That last dyno, is that "THE" poster car for AI? The Trans Am? Rick Abare's car?


That dyno graph looks like a lie detector graph, why is it all over the place?



David