EFI - need advice

[ultimacz]

I run a std. American Speed engine in my GTR (383 cui, 450BHP). Performance is quite ok (recent 1/4mile time 12sec.), but I am not happy with the carburator. I have all the well known problems like: Stalling whilst heavy breaking (not to cure, tried everything), bad starting at low temperatures (electric choke is not a good solution in my mind), drop of rpm when switching on air-con, ridiculous fuel consumption even at highway cruising speeds, fuel getting too hot when driving in heavy traffic, throttle cable difficult to adjust (either not opening fully or getting stuck),...

Therefore I want to replace the carburator by an EFI system, without changing too many other components, if possible. Has anyone done that already and can advise which components to buy and what to avoid? Cost is not an issue but the system should be easy to set up, without too much experimenting or own programming... Main concern is reliability and simplicity, I don´t want to spend then another half year to make it run properly...

Peter

[mkoch1]

electromotive makes a TecIII unit that is a direct bolt on for a small block. www.getfuelinjected.com/mpi_kits.html

Here is a link to one place I found that sells them www.racerpartswholesale.com/

This topic was talked about a few weeks ago, if you look back a page or so you'll find more info

mark

[dannylt]

Is 12s really ok for 450bhp and sub 1 ton? I would have expected it to be quicker.

[jamieheasman]

I've heard good things about the Electromotive system and it's very reasonably priced too at less than $4000USD. Remember you could sell your existing carb' and inlet manifold etc to offset the outlay.

12 secs for 1/4 mile? There's not many production cars that could better that.

[gtrclive]

For first I would remove that Auto Choke as you just don't need it. If you want you can just remove that flap and leave the mechanisium, as it will increase the rpm when stone cold. The old girls run rich enough to run when cold anyway.
The cable if it is not one of the new Tefflon coated things and it does not have Heat insulation on it, then that will cause you problems under hot standing traffic. Mine use to go stiff and raise the rpm, but does no more.

EFI does not cure all, but is alot better.

[ultimacz]

Thank you for all advices/comments. The TecIII kit looks very interesting, would be great to talk to somebody who has already used it on an AS engine.

Did anyone yet compare the TecIII, Holley and Edelbrock kits and could advise which one is best for the Ultima/AS motor?

Concerning the 1/4 mile performance: This was measured during the show program of a drag race championship (so it is accurate), the other cars in this contest were Corvettes (stock as well as highly tuned). The times for the Corvettes were all between 13 and 15 seconds. The one with the best time (just above 13 seconds) was running for sure more hp than I am, but does not have the grip of an Ultima and is probably a lot heavier. Given that a Pagani Zonda achieves 11,8 sec., my time was not so bad. Also, I am sure that a better driver than me could reduce the time further (I ran into the rev limiter at the end of the quarter mile). Also my weight is probably above 1000kg, because I fitted high end hi-fi equipment plus bigger battery and other things, also my wife insisted to stay in the passenger seat...

[davefiddes]

Teflon throttle cables sound like a great idea. Where can you get them? I fitted teflon cables to the gear shifters on my bike a month or so back. The difference in shift quality is amazing over a std cable...I can imagine how it would improve our long throttle cable.

[Chewy]

gtrclive - The new Teflon Coated cable - is that a new Factory cable. I have had problems with the cable and came to the conclusion that the outer was stretching when hot (Post ROLLING ROADS AND STICKING THROTTLE refers)
If factory cable what does it look like - mine was from factory about 6 months ago and it just appears to be standard (I suppose it must be hence problem)

[gtrclive]

Try Speedy Cables in the UK, they do Gauges and Cables. Don't know there number will have to dig it out. They advertise in the kit mags aswell.

[davefiddes]

www.speedycables.com/ seem to be the right folk? Based in Hertford.

[jschwartz]

Nearly everyone I know over here is happy with the Holley 950 Multi Port EFI unit, very user friendly and laptop tuneable. $2400 from www.jegs.com or www.summitracing.com
Includes everything, intake manifold, injectors, fuel pump and software. I saw hundreds of these units on cars during Power Tour.
Holley's a huge company www.holley.com and stand behind their product.
Jeff

[jay esterer]

I use www.sdsefi.com/ on all my project cars.
It is fast and easy to program , also no labtop PC is needed because it comes with a programing pad.

I built a mechanical throttle linkage that does not use a cable. It uses rods,belcranks and rod ends.
It has no friction and feels great. I hate 7 foot long cables, they always have too much friction.