Hello,

I am currently running a S-trim with 6-lbs boost, 24-lbs SVO injectors, and the FMU (as well as a custom tune). I am going to swap the 10-lbs puly combo on after installing Vortechs intercooler (which should net me around 8-8.5 lbs boost) I want to get rid of the FMU and retune the computer. Will 42-lbs injectors be sufficent or do I need to go with 48's? (from what I can tell I really should go with 48's?) Where can I get a good set of 48's? -I can find 42's everyware. . .

Thanks,
-Justin

 

They should be... the only way to know for sure is to check your duty cycle.

 

I run 42 Lucas injectors on mine at 8.5-9lbs with no problem. I don't remember the duty cycles though.

Do you have stock motor other than the blower?

 

Have you used the calculators?

They're quite useful for ballparking things.

 

Thanks for the info. Yes, the motor is internaly stock at this point. According to the caculators I've used, I'd be right at the point where I could go either way, 42's or 48's. I'm leaning towards the Racetronix/Delphi/Lucas 42 LBS high impendance injectors right now.

Thanks,
-Justin

 

You might be better off going with Mototron 60's so you'll have plenty of injector for later mods. I have them and they work great. Plug and Play. They have a good spray pattern which helps at low pulse widths.

 

I agree 100%. I had 42's on my stock motor with 8psi, and they were pretty much maxed out at that point. So I had to go a spend more money on a set of 60's. Might as well get those in case you do more mods. It's not gonna hurt by going to the 60's.

 

I third that. Also I wouldnt recomend pulley up without a dyno tune atleast. Listen to what others think. Learn from our mistakes.

 

I thought stock pcms can only be tuned to handle max 50lb injectors??

 

Racetronix sells 60# High Z Seimens and they work great with the factory computer. As long as you change your constant for them, you shouldn't have a problem. There pretty reasonable in price too. Mine run great.

Ken R.

 

My impresison was that the maximum the factory constant could be adjusted to was for 50lb injectors. Im more than happy to be wrong

 

Thanks for all the info on the 60's guys!

-I looked around at those Motron/Siemens 60's. . . . There seems to be two sizes, which size is correct for our appliction, the "long" or "short"? Also, what does the constant need to be set to for the Motrons? -I already have a MADZ28 tune, which I will be updating when I do the install (I'm installing the intercooler and upping the pully at the same time). -Than I do plan on getting it on a dyno for finetuning as soon as possible. -Are there any things in particular I need to look for in regards to running the 60's?

I still am interested in the RX 42's, however it makes since to go with higher (60-lbs) injectors since I eventually plan on doing the heads+cam (Though I sold the heads and cam I was going to use, so this has been pushed back a few years. . .).

 

Want to get a cheap set of 42's or 50's...go to the Lightning forums...

The 42's come stock on Lightnings so guys sell them cheap...a lot of guys then turn around and get 50's and then switch to 60's...so the 50's are just as cheap.

I bought my 50 lb. MSD's from a Lightning forum...I think I paid like $212 shipped.

 

Your tuner should be more than capable of setting the IFR for a set of 60's. I didn't see any difference in driveability or anything when I made the change from 42's to 60's. By the way, I have Mototron's. I don't remember seeing anything about tall or short sizes though. Good luck.

 

Thanks for all the input. I just ordered a set of the flowmatched Motron 60's.

-Justin