3" or 4" exhaust for over 450 whp?...
01-22-09, 12:16 PM
#26
94 Single Turbo FD
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Theres another guy who made a post with the same problem.
heres a link, check it out
https://www.rx7club.com/forum/showthread.php?t=811650
wait a minute, thats u
heres a link, check it out
https://www.rx7club.com/forum/showthread.php?t=811650
wait a minute, thats u
01-22-09, 01:33 PM
#29
Well I just wrote a very long explanation only to press the wrong button and loose everything 
Anyway, to resume what I wrote, they were supposed to do a very large streetport to simulate the behavior and idle qualities ( or lack of quality ) of the half-bridge since they told me they could do and they didnt.
So they agreed to take the engine out and do a half-bridge and put it back for free. (I hope they do not come back with some new charges for something else )
So it will be nice after this to compare the power and torque curves between the streetport and the half-bridge with all else equal.
As for the lack of power, it seems the main piece at fault is the intercooler that for some reason is not doing its job. If I am not mistaken the latest they told me was that it was lowering the IAT by about 20 degrees so if it did like the bigger intercoolers and cooled the charge by almost 200 degrees, then the difference in power would be major.
Will have to wait for now while I keep researching about exhaust, intercoolers, and the tuning with AI.
Leo
Anyway, to resume what I wrote, they were supposed to do a very large streetport to simulate the behavior and idle qualities ( or lack of quality ) of the half-bridge since they told me they could do and they didnt.
So they agreed to take the engine out and do a half-bridge and put it back for free. (I hope they do not come back with some new charges for something else )
So it will be nice after this to compare the power and torque curves between the streetport and the half-bridge with all else equal.
As for the lack of power, it seems the main piece at fault is the intercooler that for some reason is not doing its job. If I am not mistaken the latest they told me was that it was lowering the IAT by about 20 degrees so if it did like the bigger intercoolers and cooled the charge by almost 200 degrees, then the difference in power would be major.
Will have to wait for now while I keep researching about exhaust, intercoolers, and the tuning with AI.
Leo
01-22-09, 01:36 PM
#30
Talking about that, if they open the engine that has barely been broken in with all new internals after the rebuild to do the half-bridge porting, do they have to replace some of the seals again? Or they can re-use everything safely?
I think I may post this question as a separate thread later because I have to make sure they dont put back something they should replace.
Leo
I think I may post this question as a separate thread later because I have to make sure they dont put back something they should replace.
Leo
01-22-09, 02:02 PM
#31
94 Single Turbo FD
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can u really obtain the idle of a bridge port with a streetport? i have a very large streetport, but mine doesnt idle like a bridge (unless i take the map sensor hose off) maybe its just an idle speed issue, mine idles at 1100rpm.
as far as the seals go, most of it can definetly be reused as far as i know. apex seals, side seals, corners, and all the springs should be good to go, the water o-ring seals i am thinking should be replaced, need some engine builders to chime in to be sure though.
as far as the seals go, most of it can definetly be reused as far as i know. apex seals, side seals, corners, and all the springs should be good to go, the water o-ring seals i am thinking should be replaced, need some engine builders to chime in to be sure though.
01-22-09, 02:16 PM
#34
94 Single Turbo FD
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01-22-09, 02:20 PM
#35
Oh I am sorry, I forgot to answer 
They say you can do it, and I have seen some people achieve it but its not easy I guess.
I think its not only a matter of the size of the porting but the shape (for the timing of the overlap) and also a combination of all the rest of the stuff too like the exhaust, intercooler, size of turbo (the smaller the turbo, the easier it moves at idle and the more it restricts the flow )
So it seems to be possible but not easy to achieve.
Leo
They say you can do it, and I have seen some people achieve it but its not easy I guess.
I think its not only a matter of the size of the porting but the shape (for the timing of the overlap) and also a combination of all the rest of the stuff too like the exhaust, intercooler, size of turbo (the smaller the turbo, the easier it moves at idle and the more it restricts the flow )
So it seems to be possible but not easy to achieve.
Leo
01-22-09, 05:28 PM
#40
94 Single Turbo FD
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thats not the godspeed, its from a different car as classic stated in his post.
its either the pettit 3 or m2 they are the same design. they go on the forum for around 1000$ i think
heres mine, its a pettit
its either the pettit 3 or m2 they are the same design. they go on the forum for around 1000$ i think
heres mine, its a pettit
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