924Board.org

[ideola]

Roger
I've confirmed that IMI is willing to do your starter with 360° indexing. Let me know if you want to order. I've placed the initial order for 16 from the Rennlist round 2 thread, but put a provisional hold for one more for you.
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erstwhile owner of just about every 924 variant ever made

[RC]

OK, thanks Dan.

Will go with it and have just sent PP.

Got the $hits with starters ATM since Rock Auto list the wrong solenoid and I`m again stuck with a spare POS that dont fit.

[ideola]

OK, cool, I put IMI on notice, so I'll let them know in the morning to add yours to the order, no worries. Just to make sure, yours is an NA application, correct? and you'll also be needing the add'l resistor harness they made to attach to your stock harness, correct?
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erstwhile owner of just about every 924 variant ever made

[RC]

Yes, starter is a NA type.

My wiring harness is not stock and neither is the ignition system so no need for the additional diode link.

Think that the mounting angle depicted in your pics should suffice however having extra holes for 360* rotation may allow better clearance or possibly mounting with the solenoid underneath, for both clearance and temperature reasons. Can you LMK in due course if IMI foresees any problem with that?

[ideola]

Roger, there should be no problem with the 360° rotation, I've already confirmed with IMI that the solenoid can be oriented in any position with no worries whatsoever. They're on California time, so I'll get your order added a little later this morning / afternoon.
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erstwhile owner of just about every 924 variant ever made

[RC]

Looks good and well made. Lots smaller too.



Around half the weight of the stock Bosch starter.





Would I be the first to actually install one of these in a 924NA configuration? I read that they fit 944s OK and I believe 931s too. However, as they come it is not a simple direct fit in a NA. Although my headers and RHD do restrict clearance, the offset of the starter and solenoid cause interference issues. The triangulated lug is obstructed by the stock RH engine mount casting at the top. Haven`t referred to PET but think these are the same between models. The B+ stud also hits on the block and IMHO requires too much shortening, to adequately fit 2 cables and a nut. Also note how the ideal mounting falls halfway between 2 pairs of drilled holes on the flange, and this unit has extra holes too.





Now to rotate the whole thing 180*. Still won`t fit but there is more clearance. The starter body interferes with a protruding lug cast on the block, just above the sump mounting face. Also the triangular flange hits on a radiused section at the rear of the sump. And the easiest & best mounting location again falls between 2 sets of mounting holes.



The options are to drill 2 more holes and bolt head recesses in the mounting plate, between the existing holes or preferably IMO to remove the obstructions and allow the starter to rotate closer to the block. This permits the use of existing mounting holes while swinging the starter further away from the headers. So more weight reduction needed, over an ounce saved by grinding off the unused and unnecessary cast lug.



After a squirt of paint and change of terminals it manages to fit to my satisfaction. Luckily I have a pit to access the underneath easier, and it`s still a PITA job. Would not want to do it on jack stands!

[ideola]

Roger, thanks for the writeup and the pix. What a PITA having to get rid of that lug on the block.

How was the starting function once everything was installed?
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erstwhile owner of just about every 924 variant ever made

[Scorpio]

Hey Roger how did you wire it up....Youre running EFI without cold start wiring etc which is similar to my case..
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1979 NA
MS1..EFI..
GARRETT T25 TURBO
BILSTEIN SHOCKS
GT BASED CUSTOM BODYKIT

Brisbane , Australia
Think mean think fast
all youll see is
my Porsches Arse!!!

[RC]

Had to install this new starter sooner than I intended. The Bosch solenoid winding went open circuit. That has now happened twice in a 10 year period.

The engine does appear to fire up quicker than with the Bosch unit, although this is surely contributed to by all my EFI starting settings now being reasonably fine tuned. Recently upgraded to MS Extra 2.1.0 code and there are many more variables related solely to starting.

Also with the sequential CNP ignition it may be necessary to rotate the crank up to 2 revolutions before it will get a synchronised tach signal from the cam wheel. Before that occurs I don`t get a RPM reading, so in the following datalogs the engine could have been cranked over up to 2 revs before. Going to sequential ignition from a locked distributor did delay the fire up time. This new starter decreases the lag and for some reason the engine tends to start quicker than it ever did.

According to the logs the cranking RPM is actually slower than the stock unit. Battery voltage drop appears similar or marginally less. Haven`t measured cranking current yet but never took a reading with the Bosch starter to compare to. I can only assume that this IMI starter has more initial (and probably more overall) torque, allowing faster spinning and compression during the first rev or 2 that is not monitored on the log. See in the last logs, where the ignition was disabled, how the cranking RPM is very level over about 9 seconds of cranking.

First the Bosch starter:







And these are from the IMI starter:







Wiring is simple since there is only 2 connections. A heavy cable to the battery, and one to the alternator B+ from the same main stud. The solenoid primary wire just needs the terminal changed from a ring to a 1/4" female spade. With the stock ignition & wiring there will be another connection leading to the coil/ resistor. This is easily made using a crimp joiner or solder & heatshrink to the little connector plug & wires supplied by IMI. With EFI or better non stock ignition this is unnecessary since the dwell can be adjusted to compensate for any voltage drop.

[ideola]

FWIW, we can now source these individually, no minimum order necessary. MSRP is $245, but we can get these for Rennlist, Pelican and 924board members at $20 off MSRP. Contact me via PM if you're interested.

P.S. We can also get 928 starters for the same price. There's only one model across the entire lineup.
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erstwhile owner of just about every 924 variant ever made