Power Guestimates?

[Ricisan]

I already posted this on CF, nothing so far?
I can dream can't I? LOL

R

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My 74 is making 280 rwhp and 315 rwtq right now w/RHs and duals.
TFS heads, AG w/650 Demon, 218-224 HR w/1.6RRs

My question is this: Will the 315 rwtq become 315+ rwhp once the ex is unplugged? The power is already there.
How much are my smog legal RHs holding my combo back?
I go back and forth on which headers I want to upgrade to?
My cam is a tq cam, but shouldn't the tq/hp be close?
Anything over 300 rwhp and 325 rwtq should put my close to
12 sec territory! That and 20 mpg would be sweet! TIA

R

 

[mrvette]

You obviously have a closed exhaust of some type, or not on the streets for long, I suspect....

I remember a conversation with the old man at Schoenfeld headers, which are on my car for ease of wiring and clearances, and price....

HE very clearly said that putting ANY pipe behind ANY header will kill the header performance, to the point of same as not having one.....and he said with any muffler at ALL, that is the case....

just for knowing, he could have lost a sale to me right there on the spot for the thoughts he expressed....

but HIM being in the header business, I appreciated his honesty.....

so I pass along the comments FWIW....


:friends::crutches:

 

[Ozzy]

You obviously have a closed exhaust of some type, or not on the streets for long, I suspect....

I remember a conversation with the old man at Schoenfeld headers, which are on my car for ease of wiring and clearances, and price....

HE very clearly said that putting ANY pipe behind ANY header will kill the header performance, to the point of same as not having one.....and he said with any muffler at ALL, that is the case....

just for knowing, he could have lost a sale to me right there on the spot for the thoughts he expressed....

but HIM being in the header business, I appreciated his honesty.....

so I pass along the comments FWIW....


:friends::crutches:

I don't see any listings on his website for a c3 chassis. Did he custom make a set for you or ?

I am going to be in the market for a set of long tube side exit LS headers for a C3. ( think Stahl at a working mans price point )
Know of any manufacturers?

 

[mrvette]

What I have on my car some years now, is #151 called 'chassis headers' meant for some sort of roundy round cars...unequal length...but they clear the rack steering and all the rest easy....

only thing to watch out for is spark plug clearance...I have angle plug L98 heads, and so need Jacobs ceramic boots....

about 300 bux should set it all up....maybe even today....

:clobbered:

 

[Ricisan]

Big Disappointment!

Since almost everyone on this forum has more experience that I, this hard truth will have to be accepted.
I think with better ex manifold, anything has to be better than my smog legal RHs. The HP increase after 5K is minimal. I have 2.25 ex w/H pipe.
I'm hoping that 2.5 ex w/X pipe will do much better?
I would like to see a McJacks header tested?

R

 

[mrvette]

Since almost everyone on this forum has more experience that I, this hard truth will have to be accepted.
I think with better ex manifold, anything has to be better than my smog legal RHs. The HP increase after 5K is minimal. I have 2.25 ex w/H pipe.
I'm hoping that 2.5 ex w/X pipe will do much better?
I would like to see a McJacks header tested?

R

15 years ago, pre internet daze, the local vette shop recommended a 2.5" system but in them daze, no cross over tube/X in the system....since added....

My car had a 2.25 system on it, with the factory L48 engine, I don't remember when it was changed over.....as about a couple years later in '97 here in Florida, I swapped out the entire drive train.....

:beer: I have no clue as to other header makers, and in fact except for the 'headers' on my '61 Super Duty Pontiac, these are the first set of headers I have had on any car.....well there has been 3 sets on this car, two relatively quickly much earlier on with this engine....

I do note one thing though....with these factory L98 heads, the headers have never leaked, not once...bolts tight, secure fine....with the Edel heads and the factory type iron heads...I always had a header leaking....

knock on wood....:shocking: