MFI rpm limiter

[pht9]

RPM limiting on an MFI competition engine is not easy, especially to retain a period looking engine bay.

I wanted to recreate the rpm limiters like the factory used on the RSR.

Finding these original parts is very difficult, and super expensive ! - so the challenge began.

My rally car is a single plug 3.0 MFI unit. I wanted to use the 8-pin HKZ unit, to complete the engine bay detail.
My current HKZ is 6-pin*, so the challenge was to reconfigure an 8-pin unit, to interface with my current wiring loom, and incorporate the adjustable rpm limiter.
*Due to homologation restraints my engine is a single plug motor, like the SCRS

It is now completed, I will mount the second unit alongside, as a spare unit. Note the loom that acts as a 6pin to 8pin adapter, spare box and adjustable rpm limiter box. The finishing touch will be the scale decal to surround the adjuster knob

[Longballa]

Nice job. Looks great and serves a very important function. I like a rev limiter and being able to ajdust it. So, I've been putting MSD's in my cars but mounting/hiding them under the drivers seat because they look so modern on a early 911.

[pht9]

MSD make a great solution, but the FIA will not allow this system to be used for official events

[Mr9146]

MSD make a great solution, but the FIA will not allow this system to be used for official events

Many have put the MSD guts in the BOSCH housing.

I've never done this conversion, but I'd love to try it sometime.

[letsrollbabe]

Very neat solution, Phil. Are the CD housings original Turbo? Where will you mount the rev limiter?

[sithot]

Many have put the MSD guts in the BOSCH housing.

I've never done this conversion, but I'd love to try it sometime.

"Do or do not. There is no try."

(Count me in)

[pht9]

Very neat solution, Phil. Are the CD housings original Turbo? Where will you mount the rev limiter?

Gib, the 8-pin units are complete with period electronics, nothing modern in there ! - yes early Turbo units

We are fabricating a new mounting plate for the left side of the engine bay, it retains the original dimensions of the standard plate, but allows mounting of the two units (one as spare), the rpm limiter box will be positioned on the flat surface with easy access for the limiter knob. I also plan to install a start button housed in the frame, so the engine can be warmed up easier. I have no remote cold start operation on my MFI pump

The morning plate should be finished later this week, will post it up when done

[jameshtaylor]

If your rules allow an MSD, it will look a lot less obtrusive with a coat of flat black paint. Almost disappears.

[pht9]

If your rules allow an MSD, it will look a lot less obtrusive with a coat of flat black paint. Almost disappears.

I guess there is a modern solution to most items on these cars that we all love, but I think the fun is recreating the 'period looking' parts that were used when these cars were first built - with modern input for performance and reliability

[Steve@Rennsport]

Nicely done, Phil. My compliments to the "Chef".

For those who can run an MSD, these can be disassembled and the case soda or bead blasted to remove the red paint and give it a natural aluminum finish, much like the Bosch ones. Make them much less intrusive to the eye.