Im thinking of uprating the headers on my classic type ra and was wondering do they make any difference to performance.

The ones i have been looking at are the gruppe s or megan racing

 

After i had my HKS headers fitted i did notice a difference, spool up was slightly slower i think down to the larger volume of pipe work, i think they gave some extra power/torque but it was made further up the rev range 5000k+, but the sound is

I'm not sure i would have bought them had i not planned to get close to the 400bhp barrier.

As for which ones to buy out of the two you've mentioned i think the Gruppe-s look better made than the Megan racing.

 

I have the GruppeS type with anHelix up-pipe. Quite small tubes which is good for killing off some lag.
Great quality, and my engine cut (with a few additional mods) 407 x 340.

If you are not gunning for 400 bhp, then consider some stock cast headers flowed by Harvey and you will be surprised.

Graham.

 

Sorry, should add that headers arn't much use without a good open exhaust system.
Graham

 

Ive got the exhaust and a decent filter and fuel pump. The reason im thinking of getting the headers is its getting mapped in 2 weeks and want to get as much power from the map as possible

 

If your not planning on doing many more mods then porting the std headers may be a more cost affective route.

I think Harvey Smith sells them on an exchange basis, do a search on the user name Harvey.

 

How difficult would it be to do a self porting job on the cast headers your self??
I done some porting many years ago on the Inlets and outlets of my old Mini 1275GT head, Is it a case of the drill and grinding stone??

 

I have never ported headers myself, but as i understand it you need a die grinder but how much material you need to remove i have no idea.

Post a question on the subject, or better still do a search I'm sure the subject has been covered already.