Has anyone tried to port the manifold, with special attention to the lower manifold? The way these engines deliver power gets old really quick, and Im looking into a wider powerband. Its hard to find any 1uz that actually has a nice flat powercurve. Just look at Nissan V8s, they have a virtually flat curve from 5-7000rpm!

I talked to kelford about their experience with new cams, but they say the biggest problem is the manifold that leaves a lot to be desired, and did not think it would be easy to increase top end power with cams alone.


Has anyone tried porting the manifolds, and port matching it to the heads? Or even replaced manifolds with custom and dynoed it?




Sc400
BFI
Stock headers
2.5" dual exhaust
W58

 

Welcome to CL, I have only seen a custom intake on a 1uz for a supercharger. for n/a I have not seen a custom one. porting would probably help some, I did not know the intake was the restrictive part. good luck let us know what you find out.

 

Thanks!

I have searched and looked at the manifold today, and found some interesting info. First off, just looking at it the runners look really long and small. Maybe a PNP would be insufficient. I also found some threads on the subject, but they both refered to a long discussion on some V8 forum that no longer exists. They both however claimed the manifold is one of the big reasons power drops so dramatic at ~5500. Interesting, but not conclusive, as nobody had a actual dyno of a manifold that widened the powerband.


I made a call to a friend who is in the progress of building a 1uz with a supercharger. Apparently, he made a short runner manifold for his engine back when he was thinking of NA power. He sold it, but apparently it never got used. Ill see if I can get my hands on it. If not, I will simply take a weekend to PNP the stock manifold / TB etc and then see if it can make a difference. I have a local 201m (public) strip to test any modifications, I will post any results.


Still looking for input.

 

there's this
https://www.clublexus.com/forums/per...-matching.html

 

Thanks for the link oldman! Great pictures in there!

To bad he never concluded properly. "it takes less to go fast".. Well, thats a good thing, right? It looked like he could take a fair bit off them, however the manifold must always be smaller or just equal to the ports.

Ill give this a go unless I can get my hands on that custom short runner manifold. I would really love to see a dyno with a custom manifold though, to see if the gains are worth it.

 

i was gonna do the same thing, then realized there's a lot of stuff that has to come off before the manifold comes off lol. kinda need my car as a daily so i couldn't spend 3 days doing this. good luck with this, would like to see some concrete info on what this changes.