Free Chinese Headers....

[DCColegrove]

Dan- Would the gains be similar on an M50?

Mariano

M50, M50 or M50TU?

Probably yes, the early exhaust left some to be desired, but the latter stainless head pipes were pretty good right out of the box.

[DCColegrove]

nice. I'm definitely looking forward to redoing my exhaust next year. IE shorties = teh suck.

what was the torque improvement? any chance you could post a dyno chart?

No dyno chart, we could only measure HP on the old chassis dyno (the computer on the big one was broke and we only had yesterday free to get it done and run it).

From driving home I can tell that the bottom of the curve suffered a tad but the gain at the top more than makes up for it.

they are tempting at that price - but I'd rather support the guys who developed these things rather than the copies, if I can afford it. If I had the dough I'd go for those headers out of the UK (BTB?).


one more thing - what was the CR of that engine? anything done to the bottom end? I would be pretty happy with a 15hp gain on my current motor.

These are only made in China now... the real deal won't sell so they don't make them.

The bottom end is basically a stock configuration.. forged pistons but stock profile. the only other mod on the bottom was drilling the rods for piston oiling / cooling.

[z31maniac]

they are tempting at that price - but I'd rather support the guys who developed these things rather than the copies, if I can afford it. If I had the dough I'd go for those headers out of the UK (BTB?).

one more thing - what was the CR of that engine? anything done to the bottom end? I would be pretty happy with a 15hp gain on my current motor. :)

I'm with ya, I'd rather drop the coin on some Stahl headers, but $1k and still need a cat-back is bit out of this broke tech writers budget at the moment!

[Danny]

Dan- Would the gains be similar on an M50?



Mariano

Wait a second...

[nando]

Yeah I think I may actually buy these and combine it with the BavAuto Scorption exhaust.

New full exhaust for around $700.

they are tempting at that price - but I'd rather support the guys who developed these things rather than the copies, if I can afford it. If I had the dough I'd go for those headers out of the UK (BTB?).

one more thing - what was the CR of that engine? anything done to the bottom end? I would be pretty happy with a 15hp gain on my current motor. :)

[CorvallisBMW]

Wow, 17hp? That's pretty good! Granted that's on a seriously built motor, but I suppose even guys running semi-stock motors could see aroun 8-10hp. Cool, thanks for sharing Dan!

[CleanAzzE30z]

Dan- Would the gains be similar on an M50?



Mariano

[z31maniac]

nice. I'm definitely looking forward to redoing my exhaust next year. IE shorties = teh suck.

what was the torque improvement? any chance you could post a dyno chart?

Yeah I think I may actually buy these and combine it with the BavAuto Scorption exhaust.

New full exhaust for around $700.

[kenika65]

Dyno chart would be nice!

[nando]

nice. I'm definitely looking forward to redoing my exhaust next year. IE shorties = teh suck.

what was the torque improvement? any chance you could post a dyno chart?

[z31maniac]

Wow, that's pretty impressive. I realize that is on a modified engine pushing more air through the exhaust, but impressive nonetheless.

If you are running the budget stroker or similiar these would seem to be a great bang for the buck?

[DCColegrove]

Okay,

I didn't get to test them as extensively as I had hoped to (just no time) so we installed them on frankenkar and ran it before and after.

Here are the results.

On an M20B25 W/ over-sized valves, ported shaped intake, cam, software tweeks, big bore TB magnaflow cat and a hollow stock final exhaust.

Stock header pipes: 171 max br HP at the rear wheels.

Headers installed: 188 MBHPRW.

I'm sure the results on a bone stock M20 would not show this much of an increase.

There were some clearance issues:

1 oil cooler line needed relocation because of contact with cyl #1 pipe.

Transmission mount bracket touched the X pipe and required some manhandling.

O2 sensor wires needed extending by about 1/2 meter (or 318is O2 sens installed)

[CleanAzzE30z]

Personally I would never sell these and I don't think I'd use them on my car because I knew some of the guys that designed and built the originals...

And I hope they are still gainfully employed.

...

ugh!!

[nando]

I wouldn't consider those long tubes though. mid length at best. ;)

[DCColegrove]

that's not really true, a set of well designed extractors should see a healthy gain in torque. not 50ft/lbs on an m20 of course, but a nice gain.

cheesy made in china mid length headers though? yeah, i wouldn't expect much.

These are a direct copy of the headers we used on the short tracks in the early 90's. (the "long tube" headers sold all over hell are also direct copies)

The build quality is not the same but the design is sound.

Personally I would never sell these and I don't think I'd use them on my car because I knew some of the guys that designed and built the originals...

And I hope they are still gainfully employed.

...