I want to upgrade runners, Ive ported the base and plenum some, I love the torque of my car, but being TPI, obviously it isnt a high RPM machine.

Has anyone lost a low end torque feeling with aftermarket runners like SLP's, I know they will help on the top end, but I need my torque

 

What does a.e.m. in the title refer to?

 

large tubes nonsiamesed on stock base? May not gain anything but a few minor ponies you may not feel. Big gains come from big tubes + ported or aftermarket base. Gain torque and power so you shouldnt lose anything. STock base is still a restriction so increasing plenum and runner flow only helps alittle while you still choke at the base.

 

A.E.M. for aftermarket basically. I was planning on porting my base more, maybe to the point of siamesing the base itself. My upper plenum has been ported quite a bit. Also, i believe the SLP runners are siamesed on the upper end

 

You mean AS&M?
Youll gain a little torque. Not really portable but still better than stock.

 

IF you port the stock base and run SLP's with some siamesing you will shift the powerband up higher. Not too much but definately up a few hundred rpm. Car will be faster in the end, but have a broader torque curve which will feel abit different to the TPI peaky torque curve. May not make as much peak torque but will have more torque everywhere else so gives a strong pull through out the rpm band.

Usually a ported or aftermarket base with aftermarket non siamesed big tube runners will boost peak torque and hp due to air flow increases and performance at the track will show significant gains on an L98. You wont lose torque at all but still have same kind of power band and torque curve.

Both types of setups on a L98 properly geared/stalled will run similar times to a point. I think the shorter runner setups like siamesed runners will give more top end to pull the car down the track and run best ET's and MPH. Hard to say tho since the heads and cam become the restrictions. I know of bolt on large tube runner TPI L98s running about as fast as my short runner stealth ram L98 did in similar air conditions. I still give the edge to the short runners for more power under the curve, but havent proved it with engine dyno data.

 

Ever thought about using Slp runners or any other brand runner that is shorter than stock and then making 4 half inch spacers? one for each gasket? that way the runner length will equal out to stock again,but u will have bigger diameter runners. Does this make sense to anyone? I wonder if this will increase both low end torque and upper rpm torque? Just a thought