I have a b16 JDM SIRII motor with stock TB/manifold. I also have an ITR manifold. The stock IM is suppose to have a better low/mid range hp than the ITR.. but for road racing events you want all the HP gain in HIgh anyways right?

I dont care about losing hp in low because i dont drive this car on the street its for track only.

anyone with experience on this stuff thanks

 

If the IM is one of the bottlenecks for good flow, then you can gain good middle range to top end horsepower from a larger throat diameter. This applies especially to race ported heads - of course assuming you are running naturally aspirated. If your IM is not a major bottleneck, then you might pick up some top end power with the bigger diameter throat, but you may lose some bottom end at the same time.

 

so the ITR manifold would be better for road racing in long run?
since the engine isnt in the car yet i want to port match the manifold and throttle body and do a hondata gasket then put the engine in. Later I want to get race cams etc..

I want to build this engine for road racing which means i want mid to high rpm power right?




Modified by dchung1 at 10:19 PM 8/14/2004

 

no b16 with itr manifold ?

 

With the ITR, you need the power to be strong from 5000 rpm up to redline. Since you never see much less than 5k, the top end needs to flow well. If you cam the motor, make sure to at least get the head pocket ported and get a good valve job. However, first, read your rule book to see what is legal for the class you wish to compete in. If the head is open, as it is for Honda Challenge H1 class, you should consider a nice race ported cylinder head.

On another note, if you are still learning to drive fast and there is still more left in the driver part of the equation, then run the ITR relatively stock until you have progressed as a driver where you can take advantage of a modified motor. Learning to drive fast should be your first priority and modifying the motor for more top-end power should be somewhere down the list. So it is important for you to be able to judge your driving ability and also where your car needs to be modified to improve your performance.

 

thanks, i just found out the motor has gsr fuel rails and prelude injectors and is already set up for the ITR manifold so ill go ahead and swap it in stock and leave the engine like that and later when i get the cams do the head etc.. ive been doing hpde for over a year now but i wil cont to work on driving.

thanks!