siamesed intake runners.....worth it?
Thread Starter
Le Mans Master
Joined: Jun 2001
Posts: 6,694
Likes: 3
From: Less Talk, More WOT | Houston TX
siamesed intake runners.....worth it?
slp sells a set of intake runners on their site that have been siamesed for $260 i believe. Will these produce any noticible gain on a fairly stock tpi motor? Are they worth it at all?
thanks
thanks
Drifting
Joined: Nov 2001
Posts: 1,498
Likes: 0
From: Bucks county Pa
Re: siamesed intake runners.....worth it? (C4Fetish)
I was considering a set too just because they look cool. The gains they produce are more realalized top-end. I personnaly think they would be a compromise sacrificing a little low end torqe for some MPH since the long smaller runners produce low end tq.. I am sure combined with other mods they would help, but alone I dont imagine you'd feel them unless you were goin for top speed or a few MPH in the 1/4 mi. :)
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: siamesed intake runners.....worth it? (C4Fetish)
On a stock motor you will notice it pulls RPM slightly better, and won't spin as bad off the line.
Siamesing the upper plenum and thefirst inch of intake runners along with using the siamesed runners is starting to sound like the ideal way for me to go when I rebuild mine. ( Boy...I hate all the waiting I have to go through before I can do this. )
Siamesing the upper plenum and thefirst inch of intake runners along with using the siamesed runners is starting to sound like the ideal way for me to go when I rebuild mine. ( Boy...I hate all the waiting I have to go through before I can do this. )
Race Director
Joined: Aug 2000
Posts: 14,130
Likes: 7
Cruise-In II Veteran
Re: siamesed intake runners.....worth it?
Not sure if theyre worth it unless youplan to open the runner ports ALOT.I have them and took them off the car for some time now.
They take away some low speed torquewhich isnt that bad,but didnt pull as much as I hoped it would.
The port sizes on the SLP runners arent much bigger then stock and they would probably benefit more if theyre opened larger then mated to a siamesed plenum.
I have a few pics from a while back when I ported the SLP a little bit.To get an idea go to this site. http://community.webtv.net/TunePort28/
Theres been alot more work done to them since then but I had to put them on hold due to other projects right now.You can see how small the SLP ports are compared to Large Tube Runner sizes with the gasket I used in the pictures.
Also, they dont fit very well,and you have to reroute the vacuum lines on the pcv and etc on earlier L98's and need to install them before bolting the fuel rail down or they wont fit under.If you have a cold start valve,the SLPs cold start valve hole arent machined right and the CS valve wont seat all the way withut doing some grinding of the runner next to it.
Yes my car felt faster off the line with the stock runners back on.
:)
They take away some low speed torquewhich isnt that bad,but didnt pull as much as I hoped it would.
The port sizes on the SLP runners arent much bigger then stock and they would probably benefit more if theyre opened larger then mated to a siamesed plenum.
I have a few pics from a while back when I ported the SLP a little bit.To get an idea go to this site. http://community.webtv.net/TunePort28/
Theres been alot more work done to them since then but I had to put them on hold due to other projects right now.You can see how small the SLP ports are compared to Large Tube Runner sizes with the gasket I used in the pictures.
Also, they dont fit very well,and you have to reroute the vacuum lines on the pcv and etc on earlier L98's and need to install them before bolting the fuel rail down or they wont fit under.If you have a cold start valve,the SLPs cold start valve hole arent machined right and the CS valve wont seat all the way withut doing some grinding of the runner next to it.
Yes my car felt faster off the line with the stock runners back on.
:)
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: siamesed intake runners.....worth it? (Jim85IROC)
With a stock intake base, they're basically worthless. The intake base is the big restriction in a TPI setup.
