josh greene

Im taking my car into get the OMP lines fixed next week, so I was thinking of having 720 secondarys put on since he will already have the UIM off, I have a FD fuel pump and a Bosch FPR. My question is the guy Im taking it to is 3 hours away, Im planing on getting a Rtek 1.7 but not for a couple weeks, what would happen if I got 720's and had nothing to control them???
Thanks

C-Murder

really really really really rich, aka, your likely to kill a moose, or a Godzilla. You might end up flooding your car too, he. You wont want to drive it much at all. As long as you keep them off line (below when they turn on, hahahaha) then you'll be okay.
edit*the FPR will help a bunch

BUMBLEBEE7

iTrader: (1)

It will run rich but it wont flood im running 720P and 720S on a stock ecu and my car runs fine no BS. The engine is stock turbo is not. Im also runing MSDs

josh greene

Also will I want high Imp. or low Imp.??? whats the differance???




What turbo are you running???

Kingsfan

iTrader: (12)

high = S5
low = S4

J-Rat

iTrader: (2)

I ran 720s without fuel control for a while. Wasnt as bad as everyone makes it out to be.

SpeedyRotary

Well, if you do get it to run then you'll need to buy something to tune those *****! I don't see how it would hurt but you'll get horrible gas mileage probably.

josh greene

well Im planing on getting a Rteck chip in a couple weeks but I just figured if the UIM is off It would be easyer to stick them on rather then taking it off again.

Project84

That is not correct. Cars made in June of '87 that have the last 4 digits of the VIN as 7601 or higher are HIGH impedence injectors. So all the '86 cars, and half of the '87 cars have low impedence injectors, the rest of the '87 through '92 cars have high impedence injectors.

Kingsfan

iTrader: (12)

ok, so not entirely accurate

josh greene

Ok well I was looking at some gready ones on the forum and the guy says theres a way to change it from low to high???

ilike2eatricers

You will drive fine with 720 secondaries and no fuel control. Almost all injectors 720cc and larger are low impedence. Find out what impedence your car has stock and with that information you will know whether or not you need resistors. Do a search everything you want to know about resistors has been posted already.

Blowtus

you shouldn't suffer bad fuel economy, flooding, or any other major nasties at all. The secondary's only function under high load and revs, so you'll just run rich at high load and revs, which isn't particularly bad...

V8what?!

Do it. I did it for a while, and it's not as bad as everybody says it is. It is super rich, though...super rich. Say HEeeeelllLLoooo to fireballs!

Kingsfan

iTrader: (12)

http://www.rceng.com/Default.htm

RC Engineering makes 750cc high impedance injectors, anybody have experience with these?

vhold

I have the RC Engineering 750cc secondaries, it does run rich, with awful mileage, and I have had flooding - I'm getting an Rtek 1.7 to solve the problems.

No problems with the injectors themselves though.

josh greene

When are you getting the Rtek Chip???
Let me know how it works???

Smoken'

iTrader: (1)

The Rtec is awesome. The ANTIflooding function is awesome, especially if you are trying to break in a new motor like myself. It is deffinetly worth the money. Somebody was telling me that they are going to come out with another version for bigger injectors and datalog capabilities. That will really be sweet...

josh greene

there comming out with Version 2.0 that is for bigger injectors data loging and other stuff but from what I have heard its gonna be a bit more money, someone said that there trying to keep it under $500.00. but yes it will be sweet!

SpeedyRotary

i want the 2.0!!! That would be sweet, maybe i can hold off without getting a standalone for a while til then!

NZConvertible

The secondaries are not used at starting, so increasing their size cannot cause flooding.

The engine will run richer than normal above 3800rpm, but will still be perfectly driveable.

The FPR will not help at all. Reducing fuel pressure to compensate for larger secondaries will cause the engine to run lean below 3800rpm when the aren't used. Don't post bogus info that could kill an engine!

It's pointless in the short term and bad in the long run. Overly rich mixtures simply reduce power and increase fuel consumption. They also increase engine wear due to oil thinning. A couple of weeks is fine but as a permanent thing it's pretty dumb.

Your flooding has nothing to do with those injectors unless they're leaking. Flooding is caused by low compression and/or leaking injectors, not larger secondaries.

SpeedyRotary

NZ I got a question for you. If I have 720cc injectors in primary spot could that be the problem of my flooding with a moderately tuned s-afc.

ilike2eatricers

I'm not hailers but yes that could be causing your flooding problems. The SAFC cannot control the injectors during cranking.

SpeedyRotary

I only really have problems getting it started when its already been warmed up and I shut it off. Then if I go to start it, it floods. It never used to do this until I replaced the starter (my old starter would need the persuasion of a mallet to get it to crank). Sometimes I can crank it and step on the gas right before it fires and it will fire right up.

NZConvertible

Yes. The ECU doesn't use the AFM for cranking mixtures, it uses a seperate map. So the S-AFC (which intercepts the AFM) can't compensate for cranking mixtures.