[Tomiboy]

So we can tell our wives (and ourselves) that we are doing this stuff to improve our MPGs!

[PRAY]

It is all about improved efficiency. The car is still stock except for the headers. I just improve the efficiency like GM should have done from the factory.

[Tomiboy]

Originally Posted by PRAY

For those not tracking the Drag Racing forum this combo in a full weight (3,820) A8 car went consistent 10.90's to 11.0's in +3,500 DA on a drag pack. I was able to attain the #1 qualifier and the fastest pass of the event for the N/A SBE category. I also averaged 30 mph for the 1,200 mile trip from NC to BG KY. No flat land from here to there.

http://www.camaro6.com/forums/showthread.php?t=501577

Just checked out this thread. Some amazing consistency and a very quick car. You are the man!!

Were you running full E-85? Or you just added 5 gallons to the tank?

[PRAY]

Originally Posted by Tomiboy

Just checked out this thread. Some amazing consistency and a very quick car. You are the man!!

Were you running full E-85? Or you just added 5 gallons to the tank?

Thanks. I ran the car as low as I possibly could and added 10 gallons. It only got up to 73-74%. The car had more in it. I couldn't get the shift points and converter lock up to coexist. The car also runs best at 85%. I also found a table I couldn't do anything about that was pulling 3* of timing from 5 cylinders from 5,600 to 6,400. I have to run that on the dyno to see what it is worth.

This car will run within a couple hundredths if I can get the launch right every time. It is deadly consistent.

[PinHead]

Originally Posted by PRAY

Thanks buddy. I would really like to get a set of my heads on your car. Another guy that races would be awesome to back up my current results.

A converter won't hurt your roll racing. Once you click over to manual mode you are all locked up. It is just like putting it on the dyno. You can also adjust your converter lock up mph to cover down on roll racing speeds.

Any cam above 223 intake duration will usually require enough idle rpm that it will pull on a stock converter. I am not sure how the A8 stock converter fares with this but that is about the limit for all the GM converters before it.

My heads flow enough air and high enough into the lift range to handle any cam you want to throw at them. However, I am not sure on cam specs yet. It appears that there is not nearly as much PTV as I was originally lead to believe in this motor. This severely limits how far forward we can advance the IVO/IVC. The IVC directly effects the DCR we can get and therefore effects the tq we will be able to produce and where in the rpm band we can make it. Given the flow characteristics of my heads I have had the best luck running cams with a tight lobe separation 110-111 and a 6*-8* split on duration. Advance is now the issue. I would say that running a bit of advance and using the computer to retard the cam would be best. But again there is the PTV issue. We are also finding out now that there are cam retard control issues with valve spring pressure overcoming the cam phaser. I have seen this first hand on the dyno with unexplained tq dips in the curve. Once we logged cam retard we found out that cam was not following the commanded retard at all. It was retarding the cam up to 5* in certain spots for no reason. Some manufactures are now offering 0*-4* limiter blocks now vs. the 25* block that comes with the comp phaser limiter kit. We are assuming that the oil pressure and spring in the stock cam phaser can't overcome the spring pressure required to run the cams being produced right now.

I still can't wrap my head around the wide lobe sep we are seeing with most of the cam manufactures right now but no one seems to want to have a conversation about it. It seems like a double whammy to me for tq production down low. I feel it would be much better to run a tighter lobe sep with no advance than run a wide lobe sep and some advance.. There must be a definitive IVO that will maintain the minimum PTV. The other issue is ramp rate. By degreeing different cam manufactures cams there is a definite difference in ramp rates. It is the .020"-.050' that seems to be the issue for PTV with some cams and not others. So duration and IVO aren't the only issues to plan around. I will figure it out eventually with a buddy of mine and then come out with my own line of cams to match my head porting.

Excuse my naivety, (although I have an idea but want to be correct when posting a question about your runner volumes, flow rates etc)

Please define DCR, PVT, IVO, IVT

Btw do you bench you heads?

Thanks

[PRAY]

Dynamic Compression Ratio
Intake Valve Closing point
Intake Valve Open point
Inlet Valve Temp
Piston To Valve

Yes, I flow every intake and exhaust port from .300-.625 to ensure they are within 1% on my flow bench.

[PinHead]

Originally Posted by PRAY

Dynamic Compression Ratio
Intake Valve Closing point
Intake Valve Open point
Inlet Valve Temp
Piston To Valve

Yes, I flow every intake and exhaust port from .300-.625 to ensure they are within 1% on my flow bench.

Thanks

[TC2018SS1LE]

Did dyno graphs ever happen?

[PRAY]

Tons of them. Check out my FB page at Pray Performance

[TC2018SS1LE]

Thank you pay.
You selling cylinder heads now a days?