Guys, I'm at work now, but I have a few dyno pulls on the setup. I'll post the graphs when I get off work. The car initially hasn't picked up in the midrange put it did pick up in the upper RPM's which is curious to me.

 

Bad ***! I wanna see some more pics of the entire car!

 

Just a few more things to hook up and I'll be ready to fire up the motor and begin tuning. The single plane will follow sometime after that. It should be fun.

 

Good to hear Jon!

Shoot me a e-mail.

Bret

 

any new news?

 

Where are the #'s ?!

 

I've talked to Ron.... he said it makes 485rwhp consistantly on every pull and never heat soaks. Still doing a little work on it, the twin disk McCloud deal kinda made the back to backs harder to compare since it adds about 25lbs to the flywheel assembly.

Bret

 

Here's one of the baseline pulls that we did. Still working out the bugs as far as why the motor is acutally softer on the bottom end with the single plane over the GTP ported LT4 intake. The swap picked up pretty good over 6000rpm but I would also expect gains in the midrange, so we're hunting those gremlins down now. I'm also swapping to an aluminum street twin. Stock steel flywheel single disk clutches are 37#, the McLeod steel assembly is 58# and is just overkill for what I do with the car. I'm finding out that the tuning on this swap is no small feat in itself, especially when you try to keep the car driveable around town. We could do a speed density tune and pick up some power but I'm trying to keep the MAF and driveability as well.

 

Conratulations! Those are some good #'s. Just to clarify the lower blue lines on the graph under 5500 are with the new long runner intake?



We have very similar torque curves, http://web.camaross.com/forums/showthread.php?t=482833
I am hoping to be over 500 RWHP with my setup once Jeff at CAM gets a chance to turn the ***** & we put street tires on it for the dyno . I also have the street twin & 4.56’s, how much do you guys really think it will help us both to go to a lighter clutch & maybe a taller gear?



I am sure you guys will easily be above the 500 mark with 20cc more head, 28 more cubic inches, and the bigger TB on that crazy intake once the issues are sorted out. I see you are in indiana, maby in the spring time we can meet at the track & beat up on some LS cars!

 

Yep the blue is the new intake.... same cross sectional area but more runner length.

I've never seen a single plane hurt TQ yet, but the twin disk makes me think that is the loss... take the two lines at like 3200rpm, they are about 10ft lbs apart and put them together there, I think that's about what you would actually see taking the twin disk out of the scenerio. Aren't chassis dynos great! Good ole SuperFlow or DTS engine dynos, you don't have to worry about that inertia ****.

Bret

 

I dont see why the street twin would "hurt" anything with the single plane. ?? He had the street twin before right? That is not a variable that has changed since the last dyno (LT4 intake). Yes, overall the ST is heavier than the stock flywheels, but the dyno number from before were with the street twin as well. Maybe I am wrong?

 

Jason, you are right, I've had the street twin for before and after pulls. I'm just not sure why it didn't pick up. I understand the theory of longer runners, but I've never actually seen any proof that this truly is the case in an LT1 application over the LT1 intake. We'll see as I play around with a few things in the tune.

 

Looks like the fuel could be played with a bit.

Steve

 

I think the fuel looks ok (blue line is the new line). It's barely lean right at peak power and starts richening up quick after that till the end. I think the tuner did that to try to maximize power at the shift point (good idea ), which probably explains the power peak. Remember lean is fast. Too lean is slow AND broke . If you richened it up right at the end you might loose 1-2 hp at most, but it will take a bunch of heat out of the exhaust. This helps because, you don't heat cycle the chambers/ pistons too much, it would slightly add to the life of the engine.
I hope you get a chance to make some passes with it before the tracks close for the season.

 

On the new pass with the single plane, Theres an portion between 2600rpm and 3600rpm where the AF starts to head towards 13:1 the torque and hp curves also move up during this part of the pass as well. It just looks like they might have lost some of the midrange to a slightly fat A/F . The old pass (red line) looks like it was lean the whole way through. With these reverse cooled motors im pretty sure its safe to shoot for 12.8-13.0:1 A/F . I also read somewhere that the single plane will feed the cylinders more equally to help prevent any individually hot cylinders.

12.8-13.0:1 would probably be safe.. Anyone else agree?

Steve