I was thinking about welding a piece of aluminum to the runners on the inside then cutting the runners out of the middle and welding another plate on the outside and basically making them one big runner with the plenum and lower intake being siamesed also i was hoping this would help me make power to 5500 and gain some upper rpm power what do you guys think?And yes i used the ''SEARCH'' button but couldnt find anything about what i want to do so please no stupid comments..thanks

 

I have seen it done on here before, not sure where. But the guy used SLPs runners to do it, however it does make some good horsepower. I just dont know whats going to happen to your torque.

 

Basically what you are suggesting has been done a few times. However you need to do some research as to how long your runners need to be. There are formulas floating around. Try www.wallaceracing.com/calculators.htm

I bet you will need something around 13-14 inches of runner for you goals. This includes the heads. Don't even think of using the stock intake manifold.

Search under "siamese runners" and you should find a lot of information.

 

There is a guy on here who made power their .... He siamesed his runners . But his big gain came from the extrude honeing of the base ( not siamesed) ...he went to 45mm I think . He was still well into the powerband at 6000 rpm. My graph makes power all the way to 4900 solidly ...and barely falls off. But that was not tuned and running a stock vette bin file ( APYP)

 

Yes i will be using the stock lower intake but it will be really ported and opened as far as i can go,I would love to buy a new one but i just had a baby so money is going towards other things which is why i want to do this because i can do it for free,also i searched for ''siamesed runners'' but that term refers to having two runners side by side what im talking abut is just having one big runner until it goes into the lower intake not two what do you think?

 

I see no advantage to what you are trying to do. What you are doing is making one huge plenum down to the intake manifold.

What you found out in your search is others have just joined the two runners and in that manner have extended the plenum to the manifold or just short of it with some runner remaining.

What needs to be done is to find out how long the runner(s) needs to be for your combination and go from there.

 

I thought madmaxx proved this theory correct in creating a larger stronger powerband. Not saying that the math wont yeild higher numbers...just saying it worked for him and he has numbers to prove it.

 

Madmax did not have one piece runners as the poster is proposing to do.

 

anyone else have any thoughts?

 

One of the best upper RPM tpi builds I have seen was a guy who took a set of SLP runners cut them in half and fully siamesed the top half then welded them back together. He also siamesed the upper plenum.This effectively increases the plenum to make it breath .It also keeps the tuned port effect .He ran 12.2 in the quarter mile with a mild 350.

 

I would love to do that to better runners but my plan is to do it a cheap as i can and fab as much as i can also,thats why i keep pushing the stock runner issue.I wonder how that same mod would do with stock runners and a heavlly ported base?thanx for the great idea.....

 

i think it will work. i use homemade **** all the time and it works. some people just like buying expensive **** and saying that your homemade **** won't work to make themselves feel better. i say go for it and hit the dyno to prove it works. i bet you gain a **** load of power if the runners are big enough.

 

Roach thanks for the positive words,some people just dont understand that that the aftermarket came from people that didnt want to buy parts for what ever reason so they built there own,there not always as pretty but they can still look good and perform just as good sometimes even better (if your good) as the name brand stuff