current setup:
L98 355
Iron L98 heads, valve job, minimal porting
ZZ4 cam
ported plenum
hooker headers and catback

Do you guys think the SLP runners will help with my setup? From what i've read they may actually benefit since i have the zz4 cam. This is also assuming i would siamese them and port and siamese the manifold and plenum.
Thanks
JP

 

If you siamese the upper plenum & the lower plenum and port match everything then you will see some very nice gains.

Any idea what peak hp @ rpm is? With a good job you should see around about 500rpm bump to peak power, and a widened powerband with increased power going into and coming out the sweet spot.

 

Ditch the stock manifold, you need a better flowing manifold to take advantage of those runners.

 

Interesting, peak right now is about 4800 rpm. Yea, i figure a better manifold would help alot. Thanks guys.

 

A stock manifold will flow pretty good with extensive siamese and port work. However, an aftermarket manifold with the same port and siamese effort will easily outflow a stock piece.

It's up to you. YOu have the money & time to buy an aftermarket base and work on it? Or would you rather work on a base you already own?

 

Think of it this way....he could drive the car still while he is porting the runners & manifold, then just have to port the plenum when he takes the car down for the swap. Plenum porting is a snap, takes hardly any time at all.

 

I understand the trade off. I was just posing the choice to him, because he is the one doing the work

 

I'll prolly end up buying a new base. I like less down time and better performance. However its also a lot of money for an LTR setup.

 

Make sure to siamese another 1" or so into those SLP runners.
Port match everything up, and that intake will be really nice.

 

You should notice a huge gain because the other mods you have. i didn't get that much of a diff. because all i have is K&N on a 305.