engine and drivetrain Stahl Header Vs. Tii Manifold Response

[jgerock]

There have been multiple inquiries on the subject of whether or not adding a header will improve performance of an M10 engine - especially when compared to a ti/tii cast iron manifold.  Certain older Roundel magazines have included comparisons and opinions.   Here is the response from Jere Stahl in the January 1990 Roundel.

 

 

 

[M3M3]

good find!

[ray_]

Cool. I don't recall reading that one, although Redszus's comment has always stuck in my mind.

 

Thanks,

[Emyers]

Whoo Hooo.... I feel better now....heading out to the garage to re-install!

Earl

74 02Lux

02 M Roadster

72 Volvo 1800ES

[jrkoupe]

good find!

yes.............nice to read from real experts....and not web bs...

[jgerock]

I think the key to any engine performance modification is balance between the components.  Just bolting on a header to an otherwise stock engine and driving around town will not produce the desired results. 

[eurotrash]

soooo, 1.5" primary tube Stahl on a 9.5:1 bottom end.  292 cam,bowl blended head with dual 40s would be a good thing?  (I am in talks, currently, to acquire a quality used header)

Edited October 14, 2013 by eurotrash

[rey949]

After reading these articles and trying to comprehend them in their totality. All I can say is I believe my rod angle is about right when I stand about 18 inches back... And aim right for the center!

Have a nice day!

Rey

[Pamola]

Perhaps I'm just getting old but a well calibrated timing map and an engine in perfect tune seems like the best mod.... ok ok that with balancing and blueprinting during a careful build.

[Preyupy]

I think you would be better off with the 1 3/8" header with that little cam and small carbs.  You might loose a few HP at the top end but you will gain a lot in torque in the mid range.  Looks at the torque figures and where it peaks between the 1 3/8 and 1 1/2 headers on the Tii.  The smaller header is a much better compromise for a street car. 

 

Look at the AVERAGE torque through an RPM range:

1 1/2"  header  2000-5000 rpm 115.8 lb/ft average

1 3/8"  header  2000-5000 rpm 124.2 lb/ft average 

1 1/2"  header  2000-6500 rpm 99.15 lb/ft average

1 3/8"  header  2000-6500 rpm 116.2 lb/ft average

 

You need to move a LOT more air to make the larger header pay off. 

[AceAndrew]

Here's something nice to add from a customer a couple months ago.  A back to back dyno run of a stock 2002tii with factory exhaust in good shape vs.  the ie stg. 2 header (1.5" to 1.625") and stainless exhaust.  No other changes done to car.

 

[M3M3]

the dyno chart is not labeled....which is the stock run and which is the IE run Andrew?  

Edited October 14, 2013 by mlytle

[AceAndrew]

the dyno chart is not labeled....which is the stock run and which is the IE run Andrew?  

 

ha,

stock run: 94.9hp/97.1torque  

ie run:  102.65hp/105.81torque

[Rocan]

ugh, why is it speed based and not RPM based? haha

 

Also I am curious how they got those AFR's to be so spot on for both runs.... is that still running a k-fish or is it running EFI?

[ndog]

soooo, 1.5" primary tube Stahl on a 9.5:1 bottom end.  292 cam,bowl blended head with dual 40s would be a good thing?  (I am in talks, currently, to acquire a quality used header)

pm sent