Good header for Si anywhere?

[Ziggymidget5]

I know of all these headers from SMSP, Mugen, etc. are supposedly really good and noticeably increase power, but are there any good ones like these for a 1995 Si, or is DC the best option? Thanks.

[H22A1TLUDE]

DC headers suck on the prelude. You'll be better off with either SMSP, Mugen, Spoon, or Prospeed. just do some research and if you think you've found the best one then go for it. Good Luck!

[Ziggymidget5]

Yea, but don't all of those companies only make headers for the VTEC prelude, not the Si?

[H22A1TLUDE]

you know what i'm not sure if those companies only make it for the vtec prelude. thats a good question. i'll look into it.

[H22A1TLUDE]

hey try the prospeed header. i think they make them for the si.

[Ziggymidget5]

Thanks, what is their website, or where can I find info on them?

[Prelewd]

Originally Posted by junbb1 from HT

well to start off there has been a lot of bad misfortunes going on with the dyno that i tune at. but i was able to get on the dyno today to compare my dyno numbers to the JUN header that i had (basically a MUGEN header for the 4th gen).
i would first like to say that brian at prospeed told me that the car will needed to be retuned via engine management to see full potential. the car is running on the JUN p13 program.

the two graphs that you are about to look at are graphs with the euro r intake with jun header at 44psi of fuel. and the fuel curve was nice and smoothe.

the second graph is with the prospeed header at 52psi of fuel

i dont have an air fuel graph of the jun header but it was 12.9:1 to 13.2:1 range after vtec at 44psi. very smoothe and safe.

with the prospeed header at 52 psi you can see that the air fuel went to 13 to 13.5 range up top. um... this header flows a lot. it would be like 14.5 A/F at 44 psi.

but you can see that this header does take tuning to create a more user friendly powerband. you will need a hondata system or stand alone unit to maximize this header because the airfuel in VTEC is all over the place. it gets as rich as 11.8:1 at about 5900 rpm.

vtec is set at 4900. vtec comes on good but when it goes rich the power just flattens out and then it starts pulling again at 6100 rpm.

note that his is on a MUSTANG dyno not a dynojet. but it is not an MD-250 like P1 auto. it is an MD-imp/importdyne. the numbers are 5-7 whp less than a dynojet. where as P1auto's is like 20 whp less than a dynojet.

i have hondata sitting in front of me but i wont be able to in stall it for a couple of months. this motor makes about 225-227 at the wheels on a dynojet. i suspect after tuning it will hit 240.

one last time my set up is:
JUN rods
JUN pistons 87.25 mm
JUN cams and valvetrain
JUN UL flywheel
JUN cam gears 0,0
prospeed header
2.5 in mandrel exhaust with JUN ti. muffler
JUN ecu
euro r im with no egr
aem cai
mild P&P by JUN

know i need some one to upload my dyno sheets. i will email them to you to host.

here you go but if some one will host it would be easier to view.

Prospeed's website is located at http://www.prospeedpower.com but it doesn't seem to be working at the moment.

They probably wont list one for the prelude, but I guess they custom make them. The price is around $730 shipped.

[Ziggymidget5]

Thanks for the great post Prelewd. I guess the only question I have left is do you think it is worth it for the price vs. gains on a H23A? I'm still a little indecisive at the moment.

[Prelewd]

Originally Posted by Ziggymidget5

Thanks for the great post Prelewd. I guess the only question I have left is do you think it is worth it for the price vs. gains on a H23A? I'm still a little indecisive at the moment.

Personally, I'd wait for other mods. This header seems to be good if you already have a little NA internal work done and need the better flow. The h23 manifold seems to work pretty well as is. I would spend the $700+ elsewhere first, on more important things.

[lazysmurff]

just to note, my mech seems to think the h23 manifold is pretty damn good, especially if youve dont have any other major mods done.

[Ziggymidget5]

OK, thanks for all the replies. Now I don't know what to buy. Would a Random Tech or Carsound Catalytic converter do anything? Other than that I think i'd have to get the SAFC (or maybe a JET chip?) since I already have CAI and Cat-back. Any suggestions?

[Prelewd]

Random Technologies and Carsound, from what I hear, are pretty much equal in quality and performance. Personally, I wouldn't buy anything other than those two brands.

I don't think you have enough mods to get a SAFC, and I wouldn't get a JET chip, but that's my opinion. I just don't trust them.

Don't overlook your drivetrain. An LSD, lighter flywheel, and a good clutch go a long way. Preludes don't have the best brakes either.. Just food for thought.

[Ziggymidget5]

As far as a header, would a Greddy still be better than a DC?

[Prelewd]

Originally Posted by Ziggymidget5

As far as a header, would a Greddy still be better than a DC?

I'd TRUST them more.. (no pun intended ) but for a 4th gen, I wouldn't waste my money on either.