I was getting ready to order the streetable header, presilencer, and y-pipe for a NA 91 but i was reading what it said about the header and it said that it was set up more for a carburator and i want EFI. It said for the EFI just keep the manifold and replace the rest for better performance. What do you guys think, is it a big deal if i get the header performance wise, i do plan to add a supercharger and what not eventually.

 

I really liked the header I had on my 91 NA.

The power gain is not huge, but you do get better low end grunt.

I preferred the full dual setup since it wasn't as fussy about tuning.



video from inside



stereo sound

 

[quote name='NoeVuh' date='May 23 2005, 09:01 PM']I was getting ready to order the streetable header, presilencer, and y-pipe for a NA 91 but i was reading what it said about the header and it said that it was set up more for a carburator and i want EFI. It said for the EFI just keep the manifold and replace the rest for better performance. What do you guys think, is it a big deal if i get the header performance wise, i do plan to add a supercharger and what not eventually.


[/quote]



I'm curious where you saw that the road race header was meant more for carbs instead of EFI. The fuel system of a car has no affect on intake/exhaust charactersitcs of the engine. Racingbeat probably tuned the exhaust so that max scavenging and/or harmonics in the exhaust was achieved with their setup. (probably harmonics and zero scavenging since it's true dual). Anyhow the only header that makes more power are the SDJ headers and they are uber $$$$. So unless you were trying to squeek the last 5 hp out of your car in ITS or EPROD then the racingbeat unit is a fine unit.



I have never ever seen a bad racing beat product ever. That is true even when I compare greddy and apexi. Racing beat knows their stuff.

 

Racing Beat provides information on the street header vs. the presilencer and downpipe, which suggests the header does not provide significant gains on a relatively stock FI setup. Given this information is from the supplier, it would seem logical that the street or collected header is of little value on a relatively stock setup. Just a thought. Now the uncollected or racing header and true duals opens another discussion.



JP

 

I have the RB catback on my N/A and really like it. It sounds great, and felt like the car had a little bit more power afterwards. however i still have the stock headers so i dont know about gains there, but if RB says there is nothing to be gained, id believe them, they know what they're talking about, and if theres nothing to be gained, theres nothing for them to sell, and thus it cant be a marketing ploy.

 

On that RB True dual exhaust system, what do you do about the SS return pipe that goes to the air pump?? The RB system does not have anything for it to hook to. AND I was "learned" that the backpressure build up in that tube opens the 5/6th ports.



Can anybody learn me???

 

[quote name='NoeVuh' date='May 23 2005, 10:01 PM']I was getting ready to order the streetable header, presilencer, and y-pipe for a NA 91 but i was reading what it said about the header and it said that it was set up more for a carburator and i want EFI. It said for the EFI just keep the manifold and replace the rest for better performance. What do you guys think, is it a big deal if i get the header performance wise, i do plan to add a supercharger and what not eventually.


[/quote]



Its not a big deal. I've tried the RB downpipe/presilencer combo with stock exhaust mani and the streetable header/presilencer combo on a stock efi, stock port NA. I thought the pipe to stock mani had a bit better low end and the header had a bit better high end. If you want to keep going further later, you might as well get the header. Its not much more expensive.



I'd like to try the road race header and system next. I think the six port tube location looks good to provide a good deal of pressure to open them. Mine were not opening even after heavy cleaning and swapping of other actuators, with the backpressure tube location on the RB presilencer. I think that is too far down the exhaust stream if you have a pretty open exhaust after that.

 

I just ordered the true duals last night and i am going to get some cheapo mufflers tonight off ebay. Once i put them on i will post what i think.

 

This was my home built econo-rig.

I kept the flanges in front of the mufflers to simplify tranny & clutch maintenance.

The pre-silencers are $20 turbo-pac's.

It's the rig that was in the video & sound files above.

 

Here is a pic of what I just bought tonight. I'll be installing it over the long weekend!!