If max hp is at 9000rpm why are you shifting at 8700?

I don't know a thing about W7 engines but 900hp sounds a little optomistic.

[quote=GomangoCuda]If max hp is at 9000rpm why are you shifting at 8700?

I don't know a thing about W7 engines but 900hp s
ounds a little optomistic. [/qu
I got the dyno sheet. I bought it from a well-known super stock racer. Just trying to get it to run like it should

In that case you should be able to ask the guy you bought the engine from what headers you should use. Anyone who runs superstock probably has a garage full of headers that they have tried. Might even be able to buy his set from last year and save yourself some money.

I have the headers that came off of it. They just won't fit my chassis without major modifications. Just wondering if all the work will be worth it they are much larger headers.. I'm running. 1 7/8 now and the other headers are step headers 2 inch 2 1/8. 2 1/4.. with this much horsepower and RPM is it really choking it down that much that's what I'm wondering

My guess is the super stock guy probably wasn't using those headers unless they made more power than anything else he has tried.
I would try and make them work and report back.

Those headers may be and probably are hurting you some. Whats the rest of the specs on the headers, pipe length and collector diameter and length.

As Poly suggested , you don't need much of a collector length with a stall of 7000 and a peak hp of 9000 rpm. I too want to know why you shift much lower then hp peak. I'm guessing you tried shifting at and above with no difference in ET???

Pipe size has a rule of thumb with exhaust port flow for port velocity for exhaust scavenging. I don't know what a w7 exhaust port flows. But in general, you size it from that. So whats your exhaust W7 ports flow?

I think that's going to be the plan for now

[quote=AndyF]In that case you should be able to ask the guy you bought the engine from what headers you should use. Anyone who runs superstock probably has a garage full of headers that they have tried. Might even be able to buy his set from it



The headers he gave me we're on this motor on his other car. Nothing will bolt directly onto my car it has a tube chassis

[quote=hustlin hoosier]We have tried about everything possible with headers and never found over a few hundredths going from what we thought was a great set of headers to what we thought was the worst set of headers. I hope you have better luck chasing et with we exhaust than we did. [/q


How much in diameter did you change the header size

Several years back Brian( IMM engines) who posts on here ran two different sets of headers on I believe a stroker W2 motor.
Headmans and TTI headers as memory serves me.
There was a 30 or 40 horse difference between them

I wonder if there was a difference in diameter or length or what?

From everything I've read and heard about this engine combo I would lean towards the converter not being the right stall. That seems to be the biggest issues

To be running w7 heads in a super stock car, it would have to be one of the modified classes.
The whole car was likely set up around that engine package, and I'm sure part of what the op is seeing is that a class car is often a better, more sophisticated overall "package" than a typical bracket car.

Take a stock eliminator motor out of a good running stocker package and stick it in a similar bracket car and I doubt the ET's would even be close.

Another question I would have is, how close to 900hp was the performance of the car the motor came out of? Did the ET/mph/weight show it to be 900hp?

Another thought; an SS racer will kill for .02 ET. If he was running the headers that came were in the car he raced, They are probably as good as it gets, but might not show a lot of improvement. The best answer is try it and see. Be ready to tune for them, and find out EXACTLY what stall you have. I was fooled for years because I went by a tach. I am no small block guy, but hear they are sensitive to converters.

Yes one thing at a time I will put these headers on and see what happens. I had my converter stall raised from 6500 to 7000 that was all they could get out of my 8 inch converter. 60 footed a couple hundreds better but the ET remain the same

Yes his car was probably a whole lot better than mine being a super stock car. But what I really want to know is are my headers killing my motor a tremendous amount I'm going to find out over the winter

What did the car the motor came out of weigh, and what was the speed?

IMO not a converter builder, but it seems to me that in order for an 8" converter to be loosened up enough to stall 7000rpm behind a motor with less than 600ft/lbs, it would lose some effeciency in the process.

I'll throw this out there, not sure if it means much. Read about a test some engine builder did on a small block Chevy, on the dyno, with the results of dinging headers, if it lost power. They went so far as to almost flatten them completely and saw no power loss, maybe 4 or 5 hp tops, they where dumbfounded? You might see a change in a poorly designed set over a top of the line set, but not the gains you're looking for, IMO

That could be true. But what was the horsepower level of that motor? I would think this 900 horsepower motor turning 8,700 rpm it would make a bit of difference.

I would be skeptical of it being 900 hp unless I was there when they dynoed it. Did he say what mph the other car was going? The header banging was a u-tube video. I dought they could fake it.