Today I had an opportunity to do a back to back dyno of only one single component; that component being the RMW street header.

My local speed shop was willing to let me do a dyno run with the RMW Street header before I installed my stock exhaust manifold back in the car.

The current modifications on the car are as follow.

2005 JCW MCS
Alta JCW Air Filter
Alta Silicone Intake Tube
Newman Camshaft
Mynes Dyno Tune for RMW Header/Newman Cam
RMW Header / Stock Manifold

The only variance between this Dyno chart is just the exhaust manifold.

The final numbers are not really that important, but the "delta" between the two is what is important.

As you can see in the graph, the solid red line is the stock exhaust manifold while the dotted red line is the RMW Street Header.

Same goes with the torque - solid blue line is stock and dotted is RMW Street Header.

I have made the graph as large as the server allows, but if you can not read it - it basically shows that the stock exhaust manifold has both higher HP/TQ peak numbers, but also a smoother top and bottom end with the midrange being similar.

Prost
-M3NTAL-

 

Here you go...



...very interesting, thanks for posting.

EDIT: Does your stock exhaust manifold still have the pre-cat?

 

Thank you Partsman for adding that.

The exhaust manifold has not been altered in any way, shape or form.

 

You're welcome.
Wow...pretty damn good numbers and flow for the stock exhaust manifold.

 

Yes, I am very proud that the car has come this far in power with the stock manifold. The Newman camshaft seems to work well for a street vehicle.

 

Interesting results....

 

So with the RMW Street Header HP and Torque actually dropped a bit?

 

Dyno it again once you install the MegaMynes headers. That's interesting to know about the RMW header. How do they differ as far as drivability and acceleration?

 

Maybe it needs a tune?

Edit: Scratch that.

 

His car was tuned by Mynes with RMW headers on.

 

You have got to be sh**ing me. Are you trying to say that I spent $850 on a RMW header to LOOSE hp and torque and get the bonus of throwing codes that will not allow me to get thru emissons???????

 

How to you know a different tune would not fix that?

 

Well all that he did was to remove the RMW header and installed a STOCK header and made more power. Sounds like he fixed it already.

 

Very interesting, but this supports (albeit with one observation) what I've suspected all along--headers don't do much for a Mini. Cams do amazing things, but my headers (stock, cheap and expensive) don't ever seem to have added much. Of course, I also believe it's a package--system thing. Headers sound good, and when they glow red hot (mininuke) they look good!
Anyway, thanks for posting this very interesting data.

 

But.. after adding a cam, a good header is needed to optimise it right? You're right, it's a package thing.
15% Pulley
bigger injectors
Cam
Header
Cat-back exhaust
Tune

 

I could possibly re-tune it and make even more power?? I think it is tuned pretty well right now.

My "butt-dyno" feels like the car is slower because I lost the louder noise and vibration, but the car defiantly is just as fast according to the dyno.

 

I think that Mike of Mynes said that their headers improved response and gained HP/TQ vs stock.

 

hehehe..amazing results....but the good Dr Phil is right, without a cam and tune..headers dont do much...but with as cam and tune..it'll probably be amazing..

 

I think that Jan of RMW said the same thing about theirs.

 

He has a cam and a tune....

 

Paul of 1320 Autos also dyno tested it vs Janspeed headers and the RMW headers gave less Hp & Tq.

 

Thats weird bout the RMWs...I would think that it being the premium brand of RMW mods parts, it'll be pretty awesome (apart from its throwing codes and vibrations and all).

And thats why I run the Janpseed decat...so far no codes..and it sounds fricking amazing and 223HP (no tune, stock cam, stock head)...

 

Yea I heard your video in the cat-back exhaust sticky...it sounds mean .

 

heheh thanks! but now im tone deaf too LOL

 

Wow, $800 of awesome "have less" power mod? Seriously?