Page 1 of 2
4 point inj with 2 point ECU
Posted: Sun Feb 01, 2004 6:38 am
by SpidersWeb
I may of found a cheap top half of a VR4 engine. The only thing that bugs me is the fact I have four injectiors, want to use the DOHC straight away, but can't afford an aftermarket ECU just yet.
I know it can be done, because I have talked to people who did it.
He said you wire it up so two injectors fire 50% each.
Doing this would insure all four cylinders ran the same mix instead of cylinders 1 and 4 running slightly lean - which I also heard happens with the 2 injector setup.
Does anyone know the impedence of the different injectors, and if they should be wired in series or parallel, and can I make a cheap air/fuel controller by using a variable resistor on the AFM wire?
Also means I can get the twin-cam conversion done cheaply, then start saving for the next bit. Going to get my boss to do the panel work since he owes me money.
VR-4 with Starion ECU ?
Posted: Mon Feb 02, 2004 10:38 am
by David
Assuming you can get the VR-4 head to work, I would ask why bother?
You'll only get a decrease in max available power, and risk running
lean and getting fuel cut. There are some serious issues with the Starion
ECU, and you won't gain *any* significant benefit from volumetric
efficiency with a Starion ECU.
Not to mention you still need to machine the pistons, rebuild the engine
any modify the head.
So after you do around $5K of work, finding another $500 to do the ECU
should be child's play.
Just get a cheap one. Haltech or Wolf. They are both OK.
That said, you could also modify the Starion ECU, but unless you're an
electronics engineer, you'll probably pay around another $5K to get someone else to do it.
And the stock ECU maps would suck for a VR-4.
That's why people go for aftermarket.
Perhaps just look for a fuel-only ECU?
Regards
David
Posted: Mon Feb 02, 2004 11:14 am
by SpidersWeb
Besides a new exhaust manifold, VR4 head pops on easy enough, dunno why I would need to modify the pistons. I'm also not someone who just pays people to do work on my car, I prefer to do it myself with help from mechanic friends.
But yeah probably just wait until I get an aftermarket ECU to run the MPI properly, and electric ignition.
You do get a gain from running a 2x2 injector setup, however I'd agree with what you said, the 16 valve on standard Starion ECU is more likely to decrease power as I wouldn't be taking advantage of the higher flow.
Just have to wait I guess
Posted: Mon Feb 02, 2004 1:39 pm
by decoy
i beleive because the pistons are different between the vr4 and staz you'll end up with a very off compression? not sure but there's some vr4 engine parts u need to put on the staz block to get the head working on there with it.
Posted: Mon Feb 02, 2004 1:42 pm
by SpidersWeb
Yeah start on low boost, tune on dyno, if compression is too high then add another gasket.
Worst comes to worst, I'll just use VR4 rods, and pistons
Posted: Mon Feb 02, 2004 1:48 pm
by decoy
go for vr4 rods and pistons from the start ;) might as well start right with some new rings on. i think vr4 postons are stronger standard then our staz ones.
Posted: Mon Feb 02, 2004 1:51 pm
by SpidersWeb
I can get JE Forged VR4 pistons, rings and rods for $800 - better do that instead of having to change pistons twice.
Really dont like the idea of a rebuild thats all. Guess it has to be done.
Posted: Mon Feb 02, 2004 1:54 pm
by SpidersWeb
Just had bad news regarding income.
So if anyone needs any e-commerce or website development work done to a highly professional standard for cheap rates (desperate) let me know :) I have live working examples for people to check out
Posted: Mon Feb 02, 2004 1:55 pm
by decoy
well i guess it depends on how much you know about the vr4 u have now? if it's old and tired, best to rebuild now :( but hell, that sounds like a good price for those forgies and once you have done it all properly, dropped it in, u can boost up and not have to worry about pulling it out for a very long time!
Posted: Mon Feb 02, 2004 1:58 pm
by SpidersWeb
Don't have a VR4 now? Was just going to put head on my mint Starion block.
Rebuilding is just one of those asshole jobs that takes ages, then you gotta run the thing in, hope nothing breaks, etc etc, I know its something I should do, but I know its something I'm not looking forward to.
Posted: Mon Feb 02, 2004 2:53 pm
by stariontron
spider, im thinking about selling Captain Breakdown later this year, i have a reconned starion block which was going to go in there, if youre not going to have the cash for a serious attempt until later this year, maybe we could talk business?
Posted: Mon Feb 02, 2004 2:56 pm
by SpidersWeb
Sure thing :)
PM me with what you are thinking exactly as I have been awake for 2 days.
Posted: Mon Feb 02, 2004 2:59 pm
by SpidersWeb
A reconned DASH or non-DASH would be good actually.
My valve steam seals (??) are gone, apparently (according to mechanic friend) caused by heat generated by slightly worn bearings.
But yeah my big attempt looks like it'll be delayed for a while, trying to convince boss at the moment to use bartercard to get the Starion all legal and perfect again.
Posted: Mon Feb 02, 2004 3:14 pm
by SpidersWeb
just went in to the carpark for a smoke, and noticed some ass has taken one of my chrome wheel nuts off my front tyre drivers side.
grrrr
pistons
Posted: Mon Feb 02, 2004 7:30 pm
by Starion VR4
will update this thread after with the pics, VR4 pistons are very different from starions, if you use starions pistons and VR4 head the valves will touch and bend while your trying to time the cam/dissy etc( don't do it)
2nd thing the VR4 uses a optical trigger system with 4 outer slots for clyinder timing and two slots interinal on disk to reference crank position ( large slot #1 firing ) therefore you won't get the starion ECU to see a signal from resolver on back of head( starion uses a magnetic pick-up system)
3rd, you can use your standard rods on forged pistons if you hone the pin area out( most engineering shops charge $50 for all 4 rods to pin fit to fully floating rods) saving you money, std rods are good for 20PSI and 6000RPM, so save your self money and buy a ECU and better turbo
8)