These numbers were compiled from the data received from Jeff and the post was OK'd by TodaSi (Chad). The totals below are just a sum of the HP numbers at every 100 rpm. 8400 was the top rpm used since we didn't get HP/Torque numbers for every header at 8500. This HP total was from the "smoothed" data.

Header 5.5k-8.4k 6.5k-8.4k 7k-8.4k
Stock 4792.1 3407.4 2602.4
Stock w/2-1/2" 4850.6 3440.5 2624.0
DC JDM 5034.3 3559.6 2716.7
ITR JDM 5021.5 3559.5 2716.8
Jun 4983.1 3523.6 2688.0
Mugen 4991.4 3531.5 2693.9
MuTech 5006.0 3548.6 2718.3
SMSP 5043.0 3592.7 2752.5
Spoon 5049.8 3571.5 2728.4
Toda 5044.2 3583.2 2741.9
Type One 5041.3 3570.5 2723.0
Comp Tech 5019.7 3554.5 2713.2


BTW, TodaSi will be posting the specs of each header soon.

 

I've never deciphered the total HP under the curve before. What kind of difference is significant difference?


[Modified by CPR, 10:19 AM 12/19/2001]

 

Hi,

Which header has the most ground clearance? and... How long did it take you guys to install each header?

Thanks a bunch for all the information.

 

The header with the best clearnce (besides stock) was the comptech

Once we got on a roll, it took about 3-4 minutes to change headers (we let them cool for a couple mins first) thanks to whoever had those welding gloves


[Modified by sackdz, 10:27 AM 12/19/2001]

 

I'm going to try and make it easier to read.....

<BLOCKQUOTE>code:<HR><PRE>
Header 5.5k-8.4k 6.5k-8.4k 7k-8.4k
Stock 4792.1 3407.4 2602.4
Stock w/2-1/2" 4850.6 3440.5 2624.0
DC JDM 5034.3 3559.6 2716.7
ITR JDM 5021.5 3559.5 2716.8
Jun 4983.1 3523.6 2688.0
Mugen 4991.4 3531.5 2693.9
MuTech 5006.0 3548.6 2718.3
SMSP 5043.0 3592.7 2752.5
Spoon 5049.8 3571.5 2728.4
Toda 5044.2 3583.2 2741.9
Type One 5041.3 3570.5 2723.0
CompTech 5019.7 3554.5 2713.2</PRE><HR></BLOCKQUOTE>





[Modified by sackdz, 10:33 AM 12/19/2001]

 

Area under the curve is your best bet
Peak #'s are for bragging rights anyway... I don't drive around at peak power output all the time...

Will

 

what will said...

jason- who loves his fatty toda midrange

 

.....So it looks like toda came in 2nd all around? That's the all-around best performer then?

In the low range, it was 1 spoon, and 2 toda.

In the mid range, it was 1 smsp, and 2 toda.

In the high range, it was 1 smsp, and 2 toda.

hmm.....

-ken r0cker, who is off to calculate some more numbers...

 

Header Primaries Secondaries

JUN......... 45 mm.........50mm
Mugen......45 mm
Spoon..... 45 mm.........50mm
Type One 45 mm.........50mm
JDM ITR.. 43 mm
JDM DC....1.75"
Mugen/
Hytech.....45mm..............1 7/8"......65mm
SMS.........1 3/4"-1 7/8"....2 1/8"......2 1/2"
Comptech.1 1/2"-1 5/8"....1 3/4".............2"


[Modified by TodaSi, 10:43 AM 12/19/2001]


[Modified by TodaSi, 10:45 AM 12/19/2001]

 

<BLOCKQUOTE>code:<HR><PRE>
Header Primaries Secondaries

JUN 45 mm 50mm
Mugen 45 mm
Spoon 45 mm 50mm
Type One 45 mm 50mm
JDM ITR 43 mm
JDM DC 1.75"
Mugen/
Hytech 45mm 1 7/8" 65mm
SMS 1 3/4"-1 7/8" 2 1/8" 2 1/2"
Comptech 1 1/2"-1 5/8" 1 3/4" 2"
</PRE><HR></BLOCKQUOTE>

[Modified by sackdz, 10:45 AM 12/19/2001]


[Modified by sackdz, 10:46 AM 12/19/2001]


[Modified by sackdz, 10:47 AM 12/19/2001]

 

Also that looked like the JUN and Mugen header did not performance too good on a lightly modified car.
For Top end only:
1) SMSP
2) TODA
3) Spoon

Best bang for the $$:
1) JDM DC
2) JDM ITR
3) Comptech

 

and type one!

 

Everybody says look at the area below the curve. I'm trying to learn here - what exactly does this show and what is the reason behind its importance?

 

The header that with the greatest area under the curve give the most power in that RPM range. If a header give a very high peak number, but very low number else where, it wouldn't be good. I guess if you are racing, you want a header that give you the most power in a certain RPM ranges, not just a high peak number at the top.

 

In following with your findings

a.) LOW RANGE-The difference between #1 Spoon and #2 Toda was 5.6hp.

b.) MID RANGE-The difference between #1 SMSP and #2 Toda was 9.5hp.

c.) HIGH RANGE-The difference between #1SMSP and #2 Toda was 10.6hp.


The question is, are these differences significant???

 

It shows the power gain across the power band.

Example... if a header has the same power output as a stock unit up till 8,100 rpm's... then shoots up for a 16whp gain... that would be "claimed" as the "best" header to get because of the 16whp gain. In fact if another header had no peak whp gains... but had a gain of 4-5 whp throught the power band... it would be the unit for me.

Will

 

That's exactly it, Flux. For road racers, low-end to midrange power is more important for obvious reasons. You're slowing down to turn, and need more power in the low/mid rpm range to push you out of them. Then again, the peak is nice for the straights, but I wouldn't trade the midrange for anything

Again...what Willie said


[Modified by S2Killer, 10:59 AM 12/19/2001]

 

Thanks Dave. This is the type of info I have waited for. Much more informative than peak numbers. I guess I'll stick with my JDM 4-1 for the time being.

Two more things, excuse my ignorance, but what is a type one header?
And, why wasn't a hytech represented?


[Modified by Jon7, 11:01 AM 12/19/2001]


[Modified by Jon7, 11:02 AM 12/19/2001]

 

Is that whp these numbers represent?

Adding the numbers for all three areas for the top finishers:

1. SMSP - 11,388.2

2. Toda - 11,369.3

3. Spoon - 11,349.7

4. Type One - 11,334.8

Ok, so what does this mean? (Other than the fact that I just wasted some time and batteries on a calculator.....)

 

Does adding them all up make sense since the numbers represent overlaping ranges?


[Modified by CPR, 11:07 AM 12/19/2001]

 

If it were possible, you could take the hp curve for each header and define it as a function. Take the integral of it, which would give you the exact area under the curve. It would take some serious number crunching to get the right function.

 

You're right, it doesn't make sense to add them up. If you simply add them up, you will be duplicating two separate parts of the curve in the final figure. Each of the data sets Dave provided needs to be looked at individually.

 

I wouldn't look at it that way since as someone said you are adding the same ranges again.

 

CPR, it's all calculus. They are saying that at any given RPM, this header will be, on average, better than every other one that was tested. i.e. SMSP, because it has the most area under the curve.

 

Oops! on me...

I'll have to come up with another way of comparing them...