85/86 intake (for porken)
07-28-2007, 03:07 PM
#1
Nordschleife Master
Thread Starter
85/86 intake (for porken)
Well Ken,
I have done a fair bit more tuning on my 86 engine with the MSII V3.0.
I have dual 2.25" exhaust pipe, which is not mandrel bent, so it is not by far a fully optimized exhaust. However that being said it does feel like it flows more than the stock.
Now getting to the main part of the discussion, I have noticed that I am seeing a definate restriction in the intake side of the engine. I know this as I see vacuum in the intake system and get progressively more vacuum as the RPMs increase, with WOT. Now I know that my the butterfly in my throttlebody is opening up fully. So I know that isnt the restriction.
So there you have it Ken, it is confirmed that the intake is a restriction.
Now lets see all the fancy things you can come up with to get around this :P
I have done a fair bit more tuning on my 86 engine with the MSII V3.0.
I have dual 2.25" exhaust pipe, which is not mandrel bent, so it is not by far a fully optimized exhaust. However that being said it does feel like it flows more than the stock.
Now getting to the main part of the discussion, I have noticed that I am seeing a definate restriction in the intake side of the engine. I know this as I see vacuum in the intake system and get progressively more vacuum as the RPMs increase, with WOT. Now I know that my the butterfly in my throttlebody is opening up fully. So I know that isnt the restriction.
So there you have it Ken, it is confirmed that the intake is a restriction.
Now lets see all the fancy things you can come up with to get around this :P
07-28-2007, 03:54 PM
#2
Team Owner
Talk to Louie Ott he has a killer intake for the 928 , I dont know much else about it but it shure looks pretty awesome
07-28-2007, 04:34 PM
#3
Nordschleife Master
Thread Starter
Originally Posted by Mrmerlin
Talk to Louie Ott he has a killer intake for the 928 , I dont know much else about it but it shure looks pretty awesome
I am aware of that, however I had talked with Ken alittle ago and he had thought that the factory intake was restrictive, I am just giving him proof and incentive to start on it :P
07-28-2007, 08:26 PM
#4
Inventor
Rennlist Member
Rennlist Member
How are you measuring the vacuum? With a gauge, or from the MAP sensor data from the MegaSquirrel?
Louie told me that the J-bend could be improved by padding the inside radius. The bend is too short, and too sharp, so only a fraction of the 3" pipe is used. By increasing the radius, more air flows, even though the cross section is smaller.
I think the T is crap too. First, the throttle body is offset, forward of the T, second, the radii are sharp from the branch to the runs. The side plenums are good, and have tremendous volume, so what I'd like to do is replace the T, and the J, with something better. I'd like to experiment with a flappy valve too.
Because of the limited area, I think the only way to repackage the T and J would be to use fiberglass/carbon fiber to make swoopy curved manifold.
Louie told me that the J-bend could be improved by padding the inside radius. The bend is too short, and too sharp, so only a fraction of the 3" pipe is used. By increasing the radius, more air flows, even though the cross section is smaller.
I think the T is crap too. First, the throttle body is offset, forward of the T, second, the radii are sharp from the branch to the runs. The side plenums are good, and have tremendous volume, so what I'd like to do is replace the T, and the J, with something better. I'd like to experiment with a flappy valve too.
Because of the limited area, I think the only way to repackage the T and J would be to use fiberglass/carbon fiber to make swoopy curved manifold.
07-28-2007, 08:57 PM
#5
Starting over sounds like a great idea. But everyone uses a Dual resonance now, so it must be something that really works.
