My machine shop teacher was telling me today when he was a kid he heard of guys making custom TPI intake runners...he said they would take them and hollow them all out and then weld metal on the gaps, makign them look much like the SLP, i believe, the siamesed ones...have you guys heard of this at all??? do you think it can be done?? and what kind of gain do you think i'll see if I do this, and will it mess up my computer because the airflow is different???

 

A few guys have done it.

There are pics here on TGO, but heck if I know where.

Do a search for "runners"

 

Do a for "Runner glue"

 

okay i did a search, found some stuff, but i still dont' really understand....my idea was to just completely hollw the inside out, so each 2 tubes are totally connected and the inside would actually be a big oval...i think this would allow tons of air to get in there...i just want to know will this f*ck up my computer and the way it runs???

 

it wont do anything to your ECM but it will affect the way the motor will run.if that's the only modifcation that you do you may have a lean condiction,which is bad mmm-k.if your adding more air you should allso add more fuel like maybe a set of 24lbs injectors.but if you do that you should also change the injector constant in the programming
really in a perfect world you should change your programming any time you make a major change (heads,cam,intake,headers,gears,larger injectors....).that way your ECM is making the correct adjustments and your motor is running at it's best.
also would you be putting these runners ona set of stock heads?just because your intake flows a massive amount of air doesn't mean that your heads will.

wrap you mind around that

 

yea i know..but you have to start somewhere...it was just an idea...i can prolly pick up a cheap set of runners, and see how it works, then if it doesnt, oh well i won't be out too much money...i got other things to worry about this winter besides major engine mods...

 

http://sethirdgen.org/personal/siameesedrunner.jpg

these are my runners

 

thats exactly what my idea was..what kind of power gains did you see with that??

 

i have an extra set of runners sitting around that i cut up to siameese.but i desided to go a different route with my car.

 

here is a pic of one of them

 

you wanna sell them or what???you can actually knock out the metal on the bases of the flanges too right???so its like 1 big tube throughout??

 

here is another set that i used to have,sold these to another member here.

 

that looks nice...can't you connect the the 4 holes and make 2 oval shapped holes???you would get more flow that way wouldn't you? then port the pleanum to match??

 

here is a pic of my AS&M semi siemese runners.

 

wow....does that add any real performance??

 

Well correct me if im wrong but wouldent that shorten the effective runner length down to just the length of the base manifold giving a good increase in rpm potential

 

And then I sold them to another member here, and never looked back at TPI.

--Joe

 

Yep, increases plenum area and shortens runner length. Result is less velocity, but more potential for RPM.

This is of course, after you spent a weekend hogging out an aftermarket base.

-- Joe

 

This is what the AS&M runners are worth on a stock 89 Vette with headers. This was the non-siamesed version. The siamesed versions will probably sacrifice a little down low, but give larger gains up top.

https://www.thirdgen.org/techbb2/att...postid=1750460

 

the runners that i started on and a base that i started to siemesed are for sale.

 

ok then well the question then gets to be has anyone done any testing on this type of mod like before and after dragstrip times even the sotp dyno tests cause in theory it seems promising

 

this guy did some testing

 

yeah but im not talking about a siameased base im talking about just fully siameased runners now in theory a fully siameased runner would act like an extention of the plenum cutting the efective runner length down to just the base manifold which is like 6 inches you made a set of runners like im talking about correct? what differences did you notice when you put them on the car?

 

If I'm not mistaken, that guy leaned out cylinder #7 with that setup.

 

yeah but thats a siameased base im talking about just making the runners like 1 big runner like this

http://sethirdgen.org/personal/siameesedrunner.jpg

not siameasing the base, that causes bad magic in the 5 and 7 cylinders

 

I recall hearing that the problem in # 7 cyl. that guy had after siamesing the base had nothing to do with the intake itself, it was a mechanical problem that was eventually discovered.

 

siameseing the runners is not really like having a larger plenum because the runners are still not all connected except in the plenum area. it just increases the volume of each runner. so the runners are still the same length just larger for about half the distance.

 

i wonder how this person is doing with them.he's only the forth owner of these runners.

 

Good question.. They were decent runners, just the TPI that I couldn't deal with anymore.

My singleplane brought me into the 119mph range in the 1/4 on a very tired 5 year old long block.

-- Joe