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EFI - worth the cost?

S

sjd

PCGB Member
Now that the engine is fully run in, had my 930 Motec remapped by Bob Watson today.

Despite running pretty hot (intake temp on intercooler was 35 degrees and would normally be 25 degrees max on the road), the numbers at the wheels were 420 bhp and 450 lbft torque.

Having driven the car home and "opened the tap" a few times I would not doubt she is now running 500+ at the flywheel, but is key is there is no lag and max torque is being held from about 4,000 rpm.

In short - not a cheap option, but if you want to run big useable power then EFI seems the way to go.

Will talk to John Ward, but Bob would be interested in a 930 rolling day...so maybe the opportunity to get some like minded turbo fans together to swap stories...........

Simon
 
Have you stuck with the original torsion bar suspension setup or converted to coil springs? Also are you running an LSD?

Interested to know how successful the chassis is at getting that on the ground?

.....Apologies if you have already stated this on a previous thread!
 
Car runs a 3.2 G50 with an LSD.

Due to gearbox conversion I am using coilovers at the rear with 800lb springs. Have retained torsion bars for the front.

Am using 245/45 x 16 rear tyres and in the bone dry I am leaving some expensive black lines in the road each time I hit the loud pedal in second. Car steps out of line each time but the LSD catches it.

In short - it can sort of put it down, but it is at the limits and unless you are 100% switched on the car will try and kill you whenever the opportunity arises! My task was to have more power than I need fro road use ... and this seems to be about it in my experience.

The good news is that with constraint you can drive it down to the shops and it will give the best part of 30mpg on a gentle run. Bob Watson has done a great job with the Motec mapping.



 
Sounds awsome!

So is it the Motec system or the hybrid turbo that gives you zero lag? I'm assuming your running some split housing part K27, part K29?!

 
Turbo is a K27/K29 hybrid - but even with direct route exhaust manifolds I had a fair amount of lag on the CIS injection. The K27/K29 was a repacement for a K27-11 and the delivery difference was brutal.

The EFI conversion has made a real difference as it now pulls hard from 2k rpm so while the kick is still there you can feed it in more progressively should you wish.

What I should say is that to the low 400's bhp level the CIS worked great with the K27-11 (used direct route manifolds, larger intercooler, free flow exhaust, 964 cams and that was about it).

 
It would appear that you've spent a good bit of time and hard cash developing this car!

I am fairly new to this game, are the 964 cams a similar profile to the SC cams, and would that be just carrera cams or turbo cams?

Additionally I presume the G50 box makes a massive difference, I have the early 4 speed and have yet to master it! A worn syncro on 2nd doesn't help but I find the shift is too slow to keep the turbo in the sweet spot and have to blip the throttle between shifts to compensate.
 
There has been a fair amount of cash (several £10ks by the time you finish!) and certainly time in learning what works and what does not.

The 964 cams are "wilder" than the SCs. Mine came from a 3.6 Carrera and personal experience has been that these work well with both CIS and EFI.

I used the 4 speed for a number of years and also got tired of the high gearing for UK road use. I changed the ring and pinion to lower the ratios (circa 150mph top speed) and it was great. I then moved up to a 3.2 Carrera G50 box and road use flexibility improved further (but this required cutting out the torsion bar tube centre, coilover suspension, hydraulics for the clutch and a revised clutch assembly --- oh and moving the engine forward by an inch so remodelling the heat exhangers and exhaust). So not a 5 minute job!

My "recommendation" is that when you come to rebuild for the syncro look at the low ratio ring and pinion (Andial supplied mine).

best Simon
 
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