I'm currently installing an ATI P1SC on my 95 Z28 and decided that I did not want to hassle with two fuel pumps so I bought a RaceTronix kit with the Walbro GS340 high pressure 255 lph intank pump so I could run just that pump.
Is this going to be okay to use with the stock injectors and FMU for now? I plan on running either TunerCat or LT1Edit and getting bigger injectors soon but it'll have to wait for a bit.

Thanks for any info guys!!!



Seth

 

Knowing what your realistic projected FWHP, max RPM and fuel pressure will help make this determination much easier / accurate.

 

I would eventually like to see ~500 RWHP with either a 355 or 383, I would probably not turn it much more than 6000 or possibly 6200. I will currently be using the FMU until I can get ahold of some larger injectors and either TunerCat or LT1Edit. I've been told the FMU will create a 90-95 psi condition on a stock install with stock injectors. I am really questioning whether the pump will be able to keep up. Everything is stock for the time being except for the fact that I have headers and free-flowing exhaust (offroad pipe and Borla exhaust).


Thank You!


Seth

 

I was running close to 9 lbs boost and was seeing 100 psi fuel pressure on stock injectors. This was with a Vortech T-Rex pump. I didn't have any problems , but didn't feel comfortable with the possibility of going lean. Larger injectors would much safer and might save a motor.

 

The problem with stock injectors and an FMU is that the stock injectors sometimes lock closed under high fuel pressure. As you can imagine, the results are not good. Do a search on this and you'll find gobs of info.

A low buck set up is to switch to a set of 24# SVO injectors. They don't lock closed, don't require special programming, and cost only around $200.

Your single 255 lph fuel pump will be just fine with this set up. I've made 470 rwhp with only a single 255, and others have made 550+ with a single 255.

Mike

 

Thanks guys,

I will look for some SVO's then. I would have liked to wait to swap in some 30 or 36 pounders so I wouldn't have to upgrade later but I guess if this will do the trick I will look into it. I really appreciate the info.
I can't believe how many roadblocks I've run into trying to put on this d*mn blower. What a headache trying to get things to fit and work!!!
Next up from what I hear... Rebuild Club!

Ohwell, that's how it goes.


Thanks again,

Seth

 

Then again, I paid $285 for a used set of 42# injectors. Then you could ditch the FMU and install a custom program. Another board member e-mailed me my custom program and it's worked beautifully.

 

A new set of 37's from Racetronix are $303.92 currently. Most people buy the 42's. They are not much more and they give you room to grow.

FMU + F-LT1 PCM + MAF + FI = PITA

 

May I ask which program you are using to tune? I would guess either TunerCat or LT1Edit... Which is more user-friendly for the novice? I have heard/read that LT1Edit is only good on one car (i.e. one VIN) unless you register others, which is kind of a turn-off to me.
What all would I need to set up a custom tune for the stock motor with very basic upgrades (headers, borla ex., offroad pipe)? I would really seriously consider a custom tune as I am not exactly excited about running that damn FMU.
If I set up with 42 pounders and a custom tune, how much should I expect to spend? I don't mind spending a little more but I don't want to get roped into another grand at this time.
If possible I would really like to talk to one of you in person on the phone to get a little more into the details, if that's not a problem.

Again, everything is appreciated!


Seth

 

Tunercat is much easier to use and its GUI interface is great.

http://www.tunercat.com/

TTS Datamaster is a must along with their interface cable which can be used for programming and does not require phantom power like most others.

http://www.ttspowersystems.com/diagnostic.htm
http://www.ttspowersystems.com/adapt_cable.htm

Injectors

http://www.racetronix.com/Racetronix..._Sale-42s.html

 

So if I get the TunerCat program, ALDL connector, cable and diagnostic software, I will be totally set to tune on my own? I realize it might take a little playing around but this will get me going?
Is there anything else I may need, such as a wideband O2 to use this stuff? Or is it possible to tune using the stock O2's?

Thanks again!

Seth

 

Some people tune using stock O2 numbers but it is much easier and more accurate with a WBO2 system. a WBO2 system is a good long term investment. It is best to buy the tools up front and put aside some hypo parts if you are on a budget. At least this way you will be better able to get the max performance out of the HP parts you do buy and able to deal with problems if they should arise.

 

Where would a person get a WBO2 setup that is reasonably priced? It may be an option I would like to explore as well. From what I know about stock ECU's they do not accept WB's so would I also need a different datalogger too?
What is a popular setup that works well with what most people would run? I take it I would also have to weld in a bung in the ?y-pipe? for it?

-Seth

 

What is the stock LT1 pump rating, lph.

 

try this www.innovatemotorsports.com. I bought one of the first LM-1. It's a nice unit.