Koenig-Specials 928

Last weekend I drove an older BMW M5 V8 with about 400hp. It was running with an Autronic SM4 ECU system, fully programmable. Owner made swap to rid himself of aging and costly BMW replacement parts (our Hall Sensor comes to mind). It uses a MAP and no MAF. Wiring harness connects to same fuel injectors and fuel pump with it's own relay. It totally bypassed the OEM ECU and sensors. Starting and running were like brand new. the car pulls really hard in the lower gears.

This has really got me thinking. No offence to the 928 purists here but it's good to have options that are cost effective. Of course we would have to install a pot type TPS on the throttle body (easy for any alum welder). TPS housing and sensors are readilly available (Holley for ex) and cheap.

Any thoughts?

AO

There is one guy in Green Bay who is also running the Autronic setup on his 1987 928. He's got over 600RWHP!

Tom. M

Ken Osage (formerly Dean Krentz's car) is running a STI (not sure of the exact name) system on his..ran on a 5.0 with 16 valve heads, a stock 4.5 engine, and will also run on his boosted 4.5 motor too...

he is planning on getting another STI setup in the future..and possibly can get a deal if they get more orders..I think he was saying $1400 or so..normally $1700?..


Louie I believe is running a DTA system on his monster motor...

and Colin (lizard) is running another setup on his 86 motor..can't remember the name..but do recall he had it up and running in a relatively short time, and it runs strong.

RngTrtl

A guy here Lizardxxx has Megasquirt tuned up.

Lizard928

Tom, Ken is running an SDS system,
I have Megasquirt and am probably going to VEMS instead.

Koenig-Specials 928

It is reassuring to see that there is life after Porshe. Thanks for the input guys.

123quattro

I have a Haltech E6K that is going on my 84. My 91 Audi runs an 034 Motorsport IIc.

Lizard928

hessank, Check out my build project/plans topic on here, and you will see that there is for sure.

John Veninger

DTA Pro8 in mine and also Louie's stroker GT.

Louie928

I went with an aftermarket ECU for my engine. It's a DTA brand.

http://www.dtafast.co.uk/

It works like it is supposed to and I've had no problems with it. Other brands are similar I suppose. You can get an idea of what others are doing, and problems they have, here at the EFI University.
http://efi101.com/forum/index.php

I chose the aftermarket ECU route about 5 years ago when there was really no other choice. John Speake had not yet developed his Sharktuner, or fix for the LH's built in failure problem.

However, and it is a big however, there is a huge difference between getting the engine to run and getting it to run optimally under all conditions. It's not even a huge job to get the engine to run decent and make max power under a narrow range of conditions. I first ran my engine about 20 months ago. I've been mostly tuning on it since. I think it is about as done tuning as it'll ever be. I've been doing minor tweaks for about the past year. My goal was to have the engine run as well under all conditions as a stock 928. I've not reached that goal, and never will. That is mostly due to the cam duration and idle and low power area problems associated with the cams. If you are satisfied with less than stock 928 flexibility then it won't take as long. If you want the engine to start and idle without attention at -20C or colder, then you'll be out there at -20 getting the mixture correct for cold starts. You'll do it over and over again until the engine starts and keeps correct mixture until it it warmed up. If you want good starting at +40C outside temp, you be tuning at that temp too. Heat soaked hot starts are another matter and caused me a bunch of trouble until I put in a fuel temperature sensor in the fuel rail. Then made a mixture compensation table to adjust mixture vs fuel temp. You can fudge by making the mixture plenty rich. A rich mix will cover a lot of tuning sins. If you want the engine to run well at sea level and also in the mountains, you'll need to go to both extremes and adjust your compensation tables there and some points in between. Remember that timing requirements change with both air temperature and pressure so that has to be done at the extremes too. How do you set timing without a dyno or knock sensors? Some ECUs have knock sensor inputs, but parameters have to be set up for those. Sure, there are ballpark compensations but each engine is different and those are only starting points. Many ECUs have individual mixture and timing control for each cylinder, but to utilize that feature you have to have individual cylinder sensors (mixture and knock sense) to see what each cylinder is doing and make appropriate adjustments. Sequential injection compared to batch fire doesn't make a bit of difference on power. Maybe barely detectable smoother idle. Sequential injection will keep fuel pressure more stable and you can dispense with the fuel pressure dampeners we have and only need a fuel pressure regulator.

What else? Don't expect that you'll need fewer sensors than the S4 or later has. You'll still need a cam position sensor (Hall sensor) along with the crank position sensor, and temperature sensors. If you do not use the MAF, you'll need an intake air temperature sensor along with the MAP sensor. You may need the throttle position pot too. That'll depend on the ECU and how it is set up. The MAF is a wonderful sensor that'll give you an output depending on air density which is very difficult to achieve through separate pressure and temperature sensors applied to compensation tables. The MAF is quite reliable if changed out at a reasonable schedule.

I don't mean to be negative on your question. Just be aware of what is involved in an ECU changeout and the tuning job involved. With John Speake's Sharktuner available for less cost than a full featured ECU, it makes little sense to not use it. Heavily modified engines will have more need of a specific ECU, but most won't.

Paul Dortkamp

Hessank, my track car came with Motec M48, I gather it is not cheap and it is expensive to install and tune. However it runs well on the track.

Koenig-Specials 928

Thanks for the input. Oh yeah Colin, I am following your project keenly because as I wrote on the rebuild thread I am interested in the electric wp conversion. I also appreciate the time it took you and Louie to provide such details. I'm saving every word. I also would love to install ITBs on my car at some point. Hense, my interest.

Louie928

IMHO, ITBs are the way to go because they eliminate so many of the problems of an intake manifold with unequal air distribution, plus the entire intake and plenum system is always at atmospheric pressure. No leaks. That changes of course if you go with forced induction and ITB advantage becomes less. Keep up with what Adam Birnbaum is doing with his ITB setup. He's planning on using the MAF and stock LH/EZ-K system tuned with Sharktuner.

BPG_Austin

so, time to ask the pros.. My understanding was that ITB setups were part of a system. They work well with specific cams and exhaust etc.. Is there any benifits to an ITB setup on an otherwise stock 928engine?

BPG_Austin

sorry, need to rephrase that last question.
If an ITB setup is used on a stock 32v engine, enclosed in a manifold, using MAF and stock engine management, what results can be expected?