CIS with individual throttle bodies......

emcon5 · emcon5's Garage

Now here is something you don't see every day.

Car is a VW Golf, which runs a CIS variant. This guy adapted a set Suzuki GSXR 1000 throttle bodies and connected it to the CIS fuel distributor with a cable. It looks to be linear, the more you open the throttle, the more it lifts the sensor plate lever.

See the video of it running here:

http://s126.photobucket.com/albums/p118/puny_01/?action=view&current=Picture038.flv

Wow.

Tom

john walker's workshop · 12-21-2006, 05:04 PM

what a concept.

tab tanner · 12-21-2006, 05:22 PM

Great Idea, Imagine that on an early 928 with CIS

Craig 930 RS · 12-21-2006, 05:32 PM

What an annoying video.

emcon5 · emcon5's Garage

Quote:

Originally posted by tab tanner
Great Idea, Imagine that on an early 928 with CIS

I don't think "Great" is the right word. Interesting maybe.

I suppose for a race car that runs wide open in a specific narrow RPM range 95% of the time (circle track car maybe?), it could be made to work, but it would have to be tuned for that range, and all other times it would run like crap. It was easy to see how rich it was running, black smoke followed by flame from the exhaust, even backfiring through the intake a couple times.

I have to admit it is a unique approach to fuel injection.

Tom

tab tanner · 12-21-2006, 09:06 PM

Your right, great they tryed it but needs alot R/D to make it work correctly

T77911S · 12-22-2006, 05:09 AM

i would like to see a dyno with the fuel ratio across the power band.
he has eliminated the natural overswing of the plate that dumps extra fuel into the cylinders like the pump on a carb. the idle looked very high. he may of had to do that to make it drivable. is control pressure no longer a factor with the cable?

jmohn · jmohn's Garage

I've been trying to determine - what's the point? Unless, as Tom suggests, it runs "wide-open" all the time.

Jerry M
'78 SC

RarlyL8 · RarlyL8's Garage

I have been "experimenting" with CIS as well.
What this person may be looking to gain is throttle response. By mechanically connecting the fuel plunger to the throttle you remove the air sensor and the lag that goes along with it. The real trick is calibrating the cable movement to an exact spec across the throttle range.
I do not know if it is doable but plan to continue my experiment as time allows. It is great to see that someone else thinks this might work.

Wrecked944 · 12-22-2006, 05:47 AM

It is definitely a worthy effort. The throttle response from ITBs is really amazing. Anychance a similar thing might work with a DIY kit like Megasquirt? They use a MAP sensor which AFAIK does not play well with ITBs...I often wonder if a way could be found to make MAP sensors work with ITBs which would make a really cool alternative for folks who have CIS.

sammyg2 · 12-22-2006, 07:57 AM

What a hacked up cobbled up waste.
It takes the only good thing that CIS does and throws it out the window.

That system now only measures throttle position and nothing else.
No air flow, no air density, nothing. If he can get it to run smoothly at all it will be by accident and then only at one throttle position.

Craig 930 RS · 12-22-2006, 08:19 AM

Cute backyard toy wih a lot of work involved.

the · 12-22-2006, 08:43 AM

I tend to agree - interesting tinkering, but technically there seems to be a lot of reasons why that could not possibly be an improvement on a street driven car.

T77911S · 12-22-2006, 09:24 AM

i will give him this, he made it run. a lot of good ideas come from somebodies backyard.
his setup would also eliminate the horendous path the air has to take to get to the cylinders.
i wonder if you could make a plenum from the top of a 911 AFM to the top of a set of slide valve bodies from a mechanical injection sytem, think of the airflow improvement?
could you just attach the cable directly to the AFM plate, remove the TB and use the plate as the TB?