Thread: 4-1 Header for SR20ve - 200-220hp - Specs

From 3000-5300 RPMs it makes an average of about 3-4 WHP more.

From 5300-5800 RPMs it makes about the same WHP

From 5800-6400 RPMs it loses an average of 3 WHP.

From 6400-6700 RPMS it makes about the same WHP.

From 6700-8400 RPMs it makes about 10-14 WHP more.

I dont see the 7 WHP everywhere as you quoted. What I do see is a header that makes a good amount of WHP over the SSAC where it counts up top. So if he shiftes this car at 8500 RPMs it will drop down to about 5800-6000 RPMs and it will stay in its sweet spot when drag racing.

I see a header that is on average equal to SSAC from 3000-6700 RPMS and makes an average of 10-14 WHP from 7000-8400 RPMs. You just cant go wrong with that. Real power increase where you need it and no loss down low.

I Like It.

I just found the dyno for the SSAC was not close to 30deg cooler temps than the new header. I was confused with a similar dyno of the SSAC during winter. The SSAC (which was the highest for the ssac) dyno I posted was within 1deg of the new header. Though the main difference I see is the atmospheric pressure drop between the two, though maybe the humidity difference.

SSAC: 77.68 deg F, 29.19 in-HG, Humidity 32%
New Header: 78.48 deg F, 29.11 in-HG, Humidity 47%
Both at Atlantas 1000ft altitutude

I used a dyno correction calculator (Relative Horsepower Calculator) and came up with:

Calculated Relative Horsepower To Rated

SSAC 94.4%
New Header 93.4%

So its a 1% difference between the weather? So I am guessing that amounts to about 2whp extra over the SSAC that the new header makes than the dyno comparison I posted. Next time I go to the shop, I'll get them to compare both SAE corrected, but I am guessing around 2whp difference. I might be wrong, let me know what yall think.

Can I ask what gearbox has ratio's that allow such a small drop in RPM on upchanges?

With my VZR box the calcs came out to

Gear Change RPM drop (change @8500)
---------------------------------------
1 -> 2 -3514 (to 4986)
2 -> 3 -2704 (to 5796)
3 -> 4 -2283 (to 6217)
4 -> 5 -1909 (to 6591)

maybe you guys in the states have something better gear ratio wise.

I was dreaming on that one. I should have put 6000s RPMs, I was just typing off the top of my head.

Actually the gear spacing of a regular SR20DE box is tighter than a SR16VE box. Here are the number shifting at 8500 RPms

1 to 2 = 5067
2 to 3 = 5986
3 to 4 = 6444
4 to 5 = 6591

haha cool, thought i was dreaming myself when i read those figures!
And yeah, the DE box is a bit tighter between changes, but the FD makes the power a bit more usable day to day.

sorry for the off topic!

Oh i'm sorry was my "pretty much" not accurate enough. I wasn't aware that by putting an encouraging comment up about his header suddenly brought my ability to read a dyno sheet into it. The point I was eluding too was it made a solid increase "pretty much" everywhere and once tuned it will probably be a gain everywhere.

Oh Geezzzzzz

I would like to see how the fuji header would do compared to this one.