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Source for ~650cc injectors??


J Taylor

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In the process of getting SDS Ordered and need some injectors. I have the common 420's that everyone uses but I really think they are going to be a waste of time. I am looking for smething in the neighborhood of 650cc. Can anyone recommend a good place to get them from without paying a fortune?

 

JT

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Guest Anonymous

JT-

what system/options are you going for with sds? Also.. what you got under the hood that needs 650cc inj's? :eek:

I think the only oem's if you didn't want to get crazy 'spensive would be the 84-85(.5?) rx-7 gsl-se, but you're gonna have to find three cars to get em from is the unfortunate thing. I suppose scrounge some off ebay (I saw a pair go for $30!!), and have em balanced by Marren or something. Otherwise you're looking to spend some serious cash on some aftermarket high flow inj's.. accel, hks, lots of turbo places make em, and you're probably gonna pay about $100 per. I got my set of rx7 460cc's for $50! Just finished the fuel rail today! Good luck w/ scottie's!

-980mak rockon.gif

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Guest Anonymous

Tha's right... 460's, with sds em-3 6f

aughta keep the fuel down to a teeee, make the most out of the rest of my setup!

 

So John, any luck with selling the ZX? Its probably one of the nicest '79s I've seen, too bad that will have to change when I get mine done ;)

I sooooo would have bought your car if this was 1 year ago, I was looking for a good daily driver Z that was ready to go for a couple months till I found a job then could support some mods, yours would have been perfect! Now I'm knee deep in the Z, w/ many irons in a very small fire :rolleyes:

I'll be cruising down past your way onto Grant's Pass in a few weeks to pick up a borg warner t5.. I'd like to stop and Z your zee, but I might have to be making some serious time, its a 15 hour trip there/back..

I'll talk to ya soon though, you planning on turbo'in a 240?

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  • 2 weeks later...

I really think 53# will be too small. I'm probably going to end up getting some 72# injectors through a local mustang tuner. Can get 6 for about $350 which isn't bad at all. Any idea if a grand national injector will work? Precision turbo sells injectors for a good price as well but they are for GN's.

JT

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Well I found out some interesting injector info.

 

There is a 53 lb/hr injector that Plymouth used in their turbo cars, and they are 47.55 each new from my local dealer. I don't know what they look like is the problem, however, I had a buddy who got some bigger injectors for his 280 turbo from top end, and it turned out they were Chrysler injectors that he could have picked up for around 35 bucks, so I bet these will work.

 

That is about 30 bucks each cheaper than you can get them new if you bought from someone like JWT or RC.

 

Oh I bet you would like the part number, sorry. It is P5249452.

 

If it works, and you like it, let me know and send me an X-mas present. :D

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Sleeper I am kind of with you. I guess the biggest plus is it gives you a lot of room to grow, and it would be easier on the injector if you kept the duty cycle down.

 

I just hope the thing will idle properly with that big of an injector. You would really want full sequential on that deal, batch fire would probably make the thing get bad gas mileage.

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Well, I'm not really building anything all that special but I just don't want to have to upgrade again later. I'm not really concerned much with gas mileage b/c I basically only drive the car on the weekend anyway. The guy that tuned my cobra is going to tune my Z as well so I'm hoping to put up some pretty impressive numbers. He said it shouldn't be a problem getting it to idle good with the 72#'s so we will see.

 

JT

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I'd swap in the SDS first, and then look for bigger injectors. What is max duty duty cycle you are running now? The SDS will tell you this (or should).

The less you change at once, the easier it will be to debug your new system.

 

Get the SDS system in, get it tuned with your current boost level, and see where you are as far as duty cycle. Then start running more boost and upgrading injectors.

 

Just my 0.02 based on experience.

 

Pete

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Good point Zya.

 

I just hope your guy is right about those 720's. Getting them to idle on a 2.8 liter is different then getting them to idle on a 4.6.

 

You also have to be concerned about going batch fire and hosing down the cylinder walls with gasoline. That would not be good for your rings, or you oil.

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You are correct Lockjaw, the bigger the injector the rougher the idle. These 2.8L turbo motors sip the fuel at idle, and of course gulp large quantities at WOT. I'm running the 450SEL injectors, and my EFI computer reads 1% duty cycle, and I think it reads 1% because that is the smallest percentage it can.

 

When you run injectors at an extremely low duty cycle, electrical issues can arise. My car idles and runs like a champ as long as I don't have too many electrical accesories running. With the lights on, the cooling fan and heater blower running, the car will idle rough. If I start pulling injector plugs I can find one or two that do not effect the idle quality (those are the ones that are not opening due to too a small a pulse width).

 

If you go to 720cc/min injectors, I believe that you are going to have issues like this. An injector can only react to a certain minimum pulse width.

 

I'd reccomend some experimenting. The other option is to a a couple supplimental injector that modulated on only when you reach a certain boost leave. I have a friend that welded two ZXt injector bosses into the intercooler pipe right before the TB. These are staged on at certain boost levels. He says it works great. I'm not sure if the SDS can do staged injection or not.

 

Pete

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What kind of computer are you running Pete? I have the JWT upgrade. It runs quasi-sequential batch fire. That is, it fires in batches of three until it reaches 49% and the switches over to batch fire. It only has one timer. If I got one of the new infinity boxes with two timers, I could stay in te quasi mode all the time.

 

I have the 420 cc injector too, and am concerned about needing more fuel than what I can do right now. I am at a point where more boost is not really speeding my car up, but once I have the EGT going I will know why.

 

I think it could get the ecu re-chipped for those 53 lb injectors, and that should be way more than adequate. I run rich at idle, and complained about that, but I suppose I am down where you are and can't really get a lower pulsewidth. I could lower my fuel pressure though, and with the bigger injectors, the boost would crank it up there anyway.

 

I did swap out my alternator for a 87 maxima unit and got a pulley for it at a local alternator shop since I was having problems when I ran ac, lights and windshield wipers. This 90 amp maxima one took care of all of that. In fact, I think the car runs better with it. It is nicer looking with an internal fan too, so since I have the electric fan,nothing really down there that would mess up some fingers except getting them caught in a belt.

 

I have thought about the additional injector deal too. I pulled some info off the web the other day where you can use this pressure switch and a cold start injector to provide enrichment after a set amount of boost and even thought I could use two if I wanted too. Yes it would be crude, but way cheaper than an AIC or 6 bigger injectors. I am going to order one of those Chrysler injectors and see what it looks like and then see what Clark will do for me at JWT. I bet I would have to run massive boost to max those out.

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I'm running a Wolf3D with crank fire ignition. It runs in batch mode firing two injectors and two plugs at a time. Nice system. It has additional injector outputs that you can program to drive additional staged injectors. Right now I'm running 12psi, and I only log a max of 66% duty cycle, so I know I've got some reserve capacity there. I don't think I would go to larger injectors because of idle quality issues (I still want it to purr like a kitten). As I increase boost more, and I run out of capacity, I think I'll go the staged route. BTW, I'm running 38psi of fuel pressure at idle, and over 60psi at WOT.

 

Pete

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3.0l Supra run 720CC injectors as a standard upgrade, they run out of fuel at about 500RWHP on the stock 550CC injectors. Those injectors can be had cheap used but they're side feed peakhold injectors and might not work for you. the 720CC injectors that Supra upgrade to are top feed Bosch style (I'm looking for some). People often upgrade to 800+CC injectors too and apparently they idle just fine on a Supra but again that's peakhold. Right now with stock 550CC injectors I idle about .6% and that's actually a little rich. When I get my ignition running better I'll be able to lean that from 12:1 where it's at now to at least 14:1 or leaner.

 

Hrm, and Supra guys are finding that the Denso Iridium plugs make a BIG difference in our cars. These will fire in the hell that is 30+ PSI and 780RWHP!

 

Hrm, consider a W/B O2 setup. Mine is installed now and WOW does it make a difference knowing what's going on under the hood. Scottie, if you can swing the funds grab one of these puppies! DIY-O2 is the cheap way and would be perfect for your Z...

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