what do you guys think about this?

http://www.xcessivemanufacturing.com...?pid=17&step=4

 

Ok thats dandy but more important then just flow whats the drop in velocity?

 

I'm not sure about a significant flow increase, but the equal length runners are supposed to help even out the flow to the front and rear rotors. How the stock manifold is designed, the rear rotor would get more flow which would cause it to go lean and possibly preignite. There is a big thread on this topic, search for it.

 

^^ That is correct. There are a couple VERY long threads that discuss this LIM in DETAIL. They are very informative and you will gain a lot of information on this from them.

Now, I have one and it is great. Bad part is you cannot use it with the stock twins. They don't fit with this LIM. Not only this, but I am not sure if you can even get one right now. I now he was going through some shop changes. If you can get these again that would be great as it is such a good product.

 

I have this LIM on both my FDs. BOTH had correctable manufacturing flaws (one had to be planed to make the intake to housing surface flat, the other had such bad voids in the casting that it make a hole between the two primary runners).

However, the performance improvement once repaired and installed is worth while.

 

Id be really curiouse to see what sort of power/performance increase is gained from using this manifold. Anybody got any figures?

 

You can't really say exactly what type of power gain, if any this manifold will make because it can vary depending upon the application.

Obviously the higher you're boosting and the more air your pushing the greater the benefit the higher airflow lower intake will provide.

I can't tell you what difference it made on my street car as I built the motor with the XS manifold from the beginning. However, on my race car it seemed that just adding the XS manifold made almost a 10% horsepower gain at 18psi boost.

 

i have the manifold on my rx7 with dual egts in the manifold. under boost both runners are equal. nevertheless to say that is a good thing. about performance i can't say