Fuel injection/ECU ignition systems, competition engine, 3.2

[911hillclimber]

Broad questions:

Engine I have is a stock 3.2 on PMO carbs and a 2.7 Carrera distributor, points and a condenser.
The car is a hill climb car, so spends a lot of time in a 60 second run at WOT and bouncing off the rev limiter, 6500 rpm.
Economy is of no importance, good hot and cold start and reliability of tick over is.

There are 2 approaches

1
Jenvy throttle bodies built for the 3.2, made down the road from me.
Emerald ECU and control system, DIY loom.

Cost about £3500/£4000
Sell PMO's = about £2500 with manifolds, pump, regulator etc.

2
PMO injection 'tripples', Clewit sensors and loom.
Emerald ECU

Cost $4000

Any thoughts on the best system for reaching my goal?

[gridgway]

Graham, where do the PMOs fall short at the moment? I would have thought they would be ideal for WOT application.

[smallspeed]

Have a chat with Northampton Motorsport - the guys there are working on a lot of different engines/applications including a bunch of hill climb and sprint cars. the main guy there (forget his name) has a very good understanding of what's available and what is achievable and is a wizard on the tuning side too - they have in house rolling road facilities. He can also advise on a few things that are possible which you may not have considered such as launch control, traction control, etc., etc.
While carbs are good for WOT applications, I think you will get much more flexibility and control with a multi-throttle EFI set-up

I have no affiliation with NMS, I follow them on instagram, and intend using them for corner weighting/geo when my car is done - they're local to me, and from the chats I've had with them and the work I've seen, I'm more than happy to recommend them


As a disclaimer - the below isn't an advert, I am not offering services or anything, just passing on an opinion HOWEVER I am happy to help out if required/where I can with bits of machining, etc for donations to the DDK Macmillan fund.. I have also been known to work for pizza!

Personally, I'd avoid spending the money on the Jenvey set-up and DIY the throttle bodies and the installation (fuel rails, injectors, manifolds, throttle cables, etc) myself. Bear in mind, they're only supplying the throttles and the manifold, which is only about 1/3 of the battle - the "hard" bit is the linkages, although there's no reason that should be too troublesome either. I have nothing against Jenvey, and their stuff is good quality, but its easy to get the same parts and results for 1/4 the price if you're willing to do the graft

Provided the bodies and the injectors are sized suitably, and the injectors are compatible with whatever ECU you decide upon then you won't have any issues - it will also free up more of the budget to spend on the ECU / tuning side of things which will bring more of the benefits than an off-the-shelf bolt-up set of manifolds and throttle bodies

If you want to have a chat through what might be possible let me know - I've done several ITB conversions on different cars (including a 911 and a Karmann Ghia) using a couple of different control systems. If you have any question marks over throttle response on an engine with EFI and one throttle per cylinder I can fix you with one short drive

[fetuhoe]

It all sounds a bit too cheap.

When you buy the Jenvey System you don't get too much - manifolds, throttle bodies, fuel rails and a throttle crossbar.

You will still need injectors, fuel pump, pressure reg, loom fast idle system, trigger wheel, wide band lambda, throttle pot etc

I just don't think you will do this for the money as the basic Jenvey set up is the best part of £2k.

With an emerald costing £500 and allowing £500 for a good set of matched injectors such as Bosch EV16 you are running out of budget for the other parts and the loom.

The PMO system is $3200 with the manifolds and again you still need injectors and loom etc.

I think you need to budget at least £5.5k

I am not sure you will see a great deal of horsepower increase at WOT compared to carbs although it is likely to be more drivable through the mid range.

It may be worth spending a hundred quid or so on an Aldon Amethyst and tuning up the advance curve and adding a throttle pot or vacuum connection as a further refinement.

We ran a 3.0 on 46PMO's for a while on the BHRC and it always performed well, pulled like a train from 2500RPM and revved cleanly to 7500rpm on GE60's.

[Uk911]

Graham,
I spoke to the Omex guys at the Autosport show and Jenveys designer has gone to work for them, they stated they will be producing a ITB and matching ecu plus all the other bits wiring loom, fuel rail etc for 911 engines this was in Jan 16, they hoped it would be up and running by Aug 16, I haven't spoken to the guy at Omex for a couple of months now but when I do e mail him I'll copy you the reply, Raymond Boyd is also interested in a set as well. Regards Mark

72 Marmite Panzer....

[Uk911]

We ran a 3.0 on 46PMO's for a while on the BHRC and it always performed well, pulled like a train from 2500RPM and revved cleanly to 7500rpm on GE60's.

What sort of horsepower and torque did this motor produce?if you doubt mind me asking....Mark

[fetuhoe]

It produced around 265 BHP at 7250 rpm, it revved a little further than this but gave no more power.

We have our new ITBs almost ready.

The Throttle Body Castings have been made and are being machined.

The Intake Manifolds are complete.

The Fuel Distribution Blocks which also plumb in the PRV are drawn and being machined.

The Filter Housings are made and ITG have made the filters.

All the throttle hardware is the same as a 40IDA Weber.

The Fuel Distribution Blocks sits in the corner of the engine bay in the same location as an MFI pump and the Throttle Quadrant of a K Jetronic Car.

We will use a DTA management System for the prototype.

The throttle bodies have been cast with lugs for vacuum pipes for fast idle and load and there is also an air bleed for balancing - just in case.

They can be bored up to 46mm but we plan to use them at 42mm on a 3.0 SC engine for the first trials.

[911hillclimber]

Thank you all for the response. The initial 'silence' was so deafening I thought nobody had a view, weird for DDK...

The PMO's are too big for the 3.2 at 50mm throat with 34mm chokes and I always wonder if smaller would be better.

A change of PMO's = a lot of $$$$ so injection is/was a viable thought, but for what the car does £5.5K is silly.

I have been on the Northampton stand at various shows and they are impressive and not far away.

It has been some years since the car as I describe it went on Bob Watson's rollers, so maybe another option is to take it to Northampton for a 'tune-up'.
I got a lot of the parts once for a DIY Triumph ITB conversion, but sold it all as I had little confidence all the parts would really work on the big 3.2 (as opposed to their success on 2.2/2.4)

Another option is to keep the fuel system and dump the points/condenser for a 123 distributor. Their video is impressive on how stable the ignition is through the rev range.

I plan to remove and re-furb the Lola this winter so an RSR flywheel will go in and I felt it time to move the rest of the engine on and improve the gear change, the car's biggest weakness.

I know that this 3.2 will not yield more bhp but better responses will always help.

Chris: if you are reading this soon do you do RSR lightweight flywheels balanced, ready to bolt onto a 1986 3.2 flat 6?

[impmad2000]

What about the CDI+ ignition system ? This is mappable, and has shown good improvements with no other modifications. still uses the dizzy to distribute the spark, but with locked advance as timing is done electronically. Or Clewett crank fire if you want to ditch the dizzy ? This could be a quick and easy win as the fuelling stays the same.
If you want to be creative/inventive, then look at the motorbike TBs as these are designed to flow at very high RPMs. I'm a bit out of touch, but the GSXR1000s used to be popular. and they often come with injectors, fuel rail and some linkage.
For ECU, take your pick, many will have ignition options too.

[fetuhoe]

The 123 Dizzy has two versions one which has 16 preset curves and I think that this just changes a simple time constant and ramps the advance at different slopes. We fitted one to a 912 and it wasn't perfect.

The more sophisticated version is more programmable and lets you set the curve more effectively but quite costly.

The Aldon Amethyst will work with your existing dizzy , just lock out the bob weights with O rings.

The curve is fully programmable and will work with your existing points and coil.

I believe this would be just as good as the more expensive 123 unit.

We have used 3 of them now and had quite good results.

The vacuum connection works quite well and its effects are noticeable.

I agree that the 50 IDAs are a bit big but 34 mm chokes also seems a bit small. They may benefit the bottom end but could restrict WOT.

We tend to run 36mm chokes in 46's and they work OK.

I have a light 3.2 flywheel somewhere, I will dig it out an send you some information.

[911hillclimber]

Thank you Chris.

The Aldon unit I am aware of, and know Alan Goodwin well as he competes at many hillclimbs in another class. Might get an in-sight to the programming side.
I had one of his contact less systems in this 3.2 (not the amethyst) and Bob removed it as it would not run cleanly. It was Bob who put the engine on points.

Will all these systems actually improve things over the points significantly?
Hillclimbing is a very accurate and very blunt sport, sometimes just 8 gear changes and 2 hits on the brakes etc., 40 odd seconds and it all over.

The 3.2 is a very gutsy engine from 2500 to the red line, all a lot like a steam engine so flexible and good on a hill (esp in the wrong taller gear...)
Maybe 36mm might be better.

[fetuhoe]

We run Amethysts with points for exactly the same reason - we had several Ignitor style Hall Effect systems that never ran cleanly.

I read in interesting article written by Fred Winterburn, who's father designed one of the original CD Units and he is convinced that points still work well.

Programming is via a very simple JAVA Application and takes about 10 minutes using a laptop.

If the engine runs well and the gearing is wrong maybe this would be a good place to look?

[smallspeed]

were you having issue getting a clean crank signal? or do you mean the kind of "in-distributor" solutions?

[fetuhoe]

The Pertonix Style Ignitor which fits into a distributor also sold in the USA with a Brand of Hot Spark.

Pertonix don't make a unit that fits in the early Cast Iron Bosch distributors and we had a 67S with a 'Hot Spark' unit that was misfiring at around 6250rpm.

We spent too long trying to find the issue and eventually replaced the 'Switch' with 2 piece points and a condenser and it ran cleanly to the rev limiter.

We have had issues with some of the other Ignitors that are being sold and try not to use them now.

I had used the Pertronix units for years (these are sold in the UK branded by Aldon) in several Fords and never had an issue but some of the other brands just don't seem very good.

[smallspeed]

Ah ok.. I was going to say if crank fire a friend of mine has a very neat system installed on his camper van - it's completely hidden behind the fan/bottom pulley - I can get a link if there's any interest..
I think if you were a creative type and you wanted 100% stealth you could probably fit a CDI driver inside a dead distributor case and wire it like it was still running a coil and dizzy