Ive taken about around 2 1/2 inches back, should I go more or keep it there? This is for a built 355 not stock engine!!!Ive heard you are suppose to go 4 to 5 inches back is that true? If the pics dont work just go to the bottom of this site
http://www.geocities.com/softtailduece01

pics!!!!







[This message has been edited by JucinGTA (edited August 30, 2001).]

 

I may be wrong on this, but I believe you are only supposed to increase the diameter of the ports, not 'siameze' them.
This may completely destroy the bottom end torque performance of your engine.
Normally you increase the inside diameter of the ports, tapering back to around 4 inches into the base. You also need to remove the restrictions in the plenum,(plenty of articles on this one), and you can siameze the top of the runners themselves to improve the top end power, but at the sacrifice of some bottom end power.

Hope this helps, anyone else care to correct me if I am wrong?

Cheers

Richard

 

TTT anyone?

 

I wouldnt say there is a set distance, its very much uncharted territory you are in. I do think you need to make it taller though, but thats just IMO. Distance you are on your own...

To the second post, it didnt hurt my bottom end torque much, if at all... sure did help with upper end though.

 

So U think I should leave it at that and just open it up a little more in the middle? U said u didnt loose any bottom end on that? Thanks for the help!!!!

 

https://www.thirdgen.org/messgboard/...ML/001492.html

 

I did not lose any bottom end either. Now that I have my car semi tuned it still doesnt get traction until shifting into third, with 315's in the rear.

 

Well I hope my mickeys will cure that!!!!

 

Can you post the mods your have done to your car, just wondering.

------------------
89 T-Top GTA 350 5-speed (soon to be 6-speed)
(Jet hot coated)1 3/4 SLP headers,flowmaster force 2,no cat's,SLP cold air,MSD 6al,jet chip stage 2,march pulleys,ported plenum,air foil,B&M ripper shifter,180 stat,alston SFC,spohn LCA relocation brackets,free mods.

G-Tech times
0-60 5.2s
E.T. 13.91@104.8MPH

 

i completly butchered my intake,basically siemesed it!!! You can tell by my awful 60 fts it hasnt hurt bottom end! LOL

------------------
86 z28 zz4 ssm lift bars ,3.73 simesed runners and a traction deficient 13.707@101.02,on a 2.16 60 ft on 295/50/15 junk street rubber ,best MPH run 13.82@102.7,69 AMX,390 4 speed sticky tires and other stuff..12.94@102.3

 

Hey how bad did it kill your bottom end?
355 .30 over, 150 shot and other stuff


[This message has been edited by JucinGTA (edited September 01, 2001).]

 

Your 355 is bored .030 over? wouldn't that make it a 360?

 

hey just wondering if this mod would be worth doing on a stock 305 tpi with a l98 cam?

------------------
87 IROC-z 305 TPI 5spd 10-bolt 3.73 posi ,8.8 Accel wires , bosch platinum +4 plugs,MAF sensor screens removed, gutted air box, ram air, K&N air filters,TB coolant bypass ,polyurethane tranny and torque arm mounts, K&N oil filter,Mobil 1 synthetic oil 20w50, futura GLS super sport tires 265/50/15 rear and 235/60/15 front mounted on 86 monte carlo SS rims ,

400 sbc and a 6 spd in the works

 

I'd like to find out the answer to that question myself... I *may* do that, and this time I will see what I can do to get results from a lower RPM, that would be really nice.

 

Did you port out the inside of the cold start injector on the manifold????? Will this do anything performance wise?

 

No I didnt. I deleted out the cold start!!!