Micra Group A Rally Car

Low Rider

Poindexter
Staff member
#51
I see 👍

Have people tried different design exhaust manifolds other than janspeed. ?
Matt Humphris has.

There are several manifold variants he offers. His Janspeed manifolds, which are essentially what Maniflow made back in the day, have much bigger ports which pushes peak torque and horsepower up the rev range. He also does a longer primary version to help boost torque. I believe he's done some dyno work on them and may have some info on benefits.

Eden from Gizfab does a few variants also but I don't know if anyone has had one on a serious motor on the dyno yet.

I'm also wondering what AP Race Engines may use as they seem to get good results out of CG13/CGA3 engines.
 
Last edited:
#53
Matt Humphris has.

There are several manifold variants he offers. His Janspeed manifolds, which are essentially what Maniflow made back in the day, have much bigger ports which pushes peak torque and horsepower up the rev range. He also does a longer primary version to help boost torque. I believe he's done some dyno work on them and may have some info on benefits.

Eden from Gizfab does a few variants also but I don't know if anyone has had one on a serious motor on the dyno yet.

I'm also wondering what AP Race Engines may use as they seem to get good results out of CG13/CGA3 engines.
Do you have any dimensions from the jenvey throttle bodies that people use on the micra ?

spacing between the bodies , what the size is the bore on the manifold side , is it the taper sf bodies most people use ???
 

Low Rider

Poindexter
Staff member
#54
Do you have any dimensions from the jenvey throttle bodies that people use on the micra ?

spacing between the bodies , what the size is the bore on the manifold side , is it the taper sf bodies most people use ???
Yes, I have a set on my desk as it happens :)

Bore spacing is 79mm, bodies are SF taperbore 42-45mm. The manifolds are finished bored to 42.5mm from Jenvey but they end up 42.75mm to fully match the SF body units, at least they do on my set. Mine are however ex NME units with a different setup than they make now, as they have bespoke inlet trumpets with injector mounts for 4 stand-off injectors.
 
#55
Yes, I have a set on my desk as it happens :)

Bore spacing is 79mm, bodies are SF taperbore 42-45mm. The manifolds are finished bored to 42.5mm from Jenvey but they end up 42.75mm to fully match the SF body units, at least they do on my set. Mine are however ex NME units with a different setup than they make now, as they have bespoke inlet trumpets with injector mounts for 4 stand-off injectors.
cheers do you have pictures please , how is the linkage on those ?

thanks
 
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