EFI/Weber guy from the Cobra community

[Paul Proefrock]

I've come over to this forum, in addition to ClubCobra, to research info on Webers and EightStack systems. I am currently running a Ford FE in a Cobra replica with Weber 48 IDA's. Recently became the proud owner of an EightStack system and working on the details to make it operational.

Attempted to connect to some of the members but it told me I had to post something first. I've lurked on this thread since July 2013 when I first added the Webers. Guess it's time to come public.

Pictures of car and motor are at this page: 65shlb.com The site, other than a few pictures, hasn't been upgraded since I put the weber's on. My build originated with a 3x2 setup but that wasn't enough eye candy - plus it has some real performance issues when subjected to high G forces when braking. (Gets reeallll exciting when the engine stalls during a high speed braking and turning maneuver :shocked: )

Thanks

Paul Proefrock
Manchester, MO

 

[Pierre-Louis]

Hello welcome,

One of my friend has put the EightStack EFI system on his engine (SBF 363 ci).

On his thread, you can see a dyno run of the engine with the EFI fitted. Runs nice !
As the car is not fully completed at the moment, he has not been able to road test it, but this should be done this summer. I'll let you know (don't try to PM him, he doesn't speak English and probably doesn't come here very often).

http://www.gt40s.com/forum/gt40-build-logs/38256-original-gt40-sbarro-2.html

See post # 40

 

[Dwight]

Paul how old is your Eight Stack system?

I bought a GT40 with the Dynotec system on it. The car would not run. Lots of problems. I think it was what I would call a second generation unit.

In the mean time Dynotec company sold and became Eight Stack. I contacted Dale with Eight Stack and they updated and tested my system. They moved the TPS to the number 1 / 2 position, throttle pulls from the center not the side, flow tested and balanced the TB.

It's installed but I have not started the motor.

I bought a new harness and ECU. I'm in the process of wiring it.

Dwight

 

[Tim Kay]

Hi Paul,

First, welcome to the GT40s forum, good to have you and it'll be nice to hear about your cobra experience. I've been running a Borland unit (formerly TWM) since 2006. Installed it on a brand new 351W build and we spent many hours on the dyno trying to get the motor tuned (never suspecting the 'new' TWM induction) only to find out the thottle bodies had to be sent to TWM and re-built. We had taken the new bodies apart to powder coat and did not put them back together correctly, throttle shafts needed alignment. Seemed straight forward at the time but they are pretty sensitive to adjustment. Once we got that right they were 'sweet' and are still running with no issues. Moral is, especially if you purchased second hand, have them rebuilt by the manufacturer.

Also, seemed unique to my motor but tuning on a chassis dyno revealed above normal advance timing to remove a "lean pop" under agressive acceleration. Anyway, I wouldn't hesitate to do it again and highly recommend the eight stack efi systems. Oh, one thing I would do different is coil packs rather than an electronic distributor. I've replace three dizzies at $400 a piece due to what appears to be electrical spikes which damage the sensitive circuit board.

Now, I'm going the other direction, working on a 302 with IDA's. If you happen to have a Weber jet kit for sale I'd be interested in purchasing it.

Have fun,
Tim K

 

[Paul Proefrock]

Thanks, guys.

The first thing I've done is send the electronics back to Performance Electronics for updating and the carbs/injectors back to Borla for rework. Dale confirmed they had issues when first built with air leakage but have figured out how to fix them. Think I am in good hands with them.

My system came with an Idle Air control that bleeds air into the vacuum plenum to maintain proper idle. Is anyone else running this?

My distributor is a Mallory UniLite and I plan to block the advances out of it and use the sensor as a signal source. Anyone running Mallory or is everyone MSD fans?

Paul

 

[Tim Kay]

Paul, when I did my build I opted for the Accel Dual Sync Distributor which was my only option at the time that would fit in the low clearance under the inboard fuel rails. By the looks of the Mallory, it appears it will have a similar fit and won't be an issue for you but double check the clearance if in fact you have fuel rails mounted between the 'stacks'. In any case, I do not recommend the Accel brand.

I am not running an idle air control, can't help you there.

Tim

 

[Dr. Bob Woods]

Paul,

I have a 363 SBF with the Borla 8 stack with the Performance Electronics EFI. I have the idle speed control and dual wide-band O2 sensors. My engine is built but I don't have the fuel injection or engine installed. So you guys are ahead of me but we are going down the same path. I have a long term relationship with Performance Electronics so I will be able to get a lot of help with my system.

We should all keep in touch about our developments.

Bob Woods
Tornado GT40 in Texas

 

[Dave Hood]

My car was installed with the original Eight Stack EFI prototype. It is correct that the early versions had lots of problems due to tolerance issues in the stacks. Dale Schaller at Eight Stack essentially rebuilt my unit about three years ago and it's run great ever since. It was installed and fine tuned by Dennis Olthoff. Borla, who bought Eight Stack last year, is the third owner of the system. I'm confident that any bugs have been worked out at this point. Dale is now working for Borla, and he's a great person to work with. Very honest, up front and knowledgeable.