What size injectors??

[talontedtsi1995]

Hello, I have a 1996 eagle talon tsi with 3 inch turbo back exhaust without cat, FP T-28 turbo, and a walbro 255 lph fuel pump, my car boost 15 lbs with out a boost controller, even with one on turned all the way down it would still boost 15, once it hits 15 lbs the car still gets fuel cut so I am looking to get fuel injectors but not sure what size would be best for me?

 

[spyderturbo007]

That depends on a lot of variables. What are you planning on tuning them with? Do you ever plan on upgrading your turbo?

 

[ivanr4g63]

If you plan to keep this turbo, a set of 550's will do the job, and I sure hope you current FPR is doing ok, but in most cases you could be overriding it with such a big fuel pump, (unless you have an aftermarket FPR) but if not, you could be runing with the wrong fuel compensation and causing the car to go lean on high rpm and cause the fuel cut, because with your turbo set to 15psi you should be ok even with stock injectors, another thing to check is your current boost gauge, you might be spiking boost to over 15 at higher rpm and get fuel cut for that as well, also an AFC could be a better choice at this point.

On another subject, if you plan on going with bigger turbo, you might want to consider 650's and an AFC, or bigger injector and better fuel management system, depends on your budget, but if you plan to stay like this for a while, I'd say find yourself a nice set of used 550's for cheap, something to datalog and tune with and happy boosting. your setup should be good for a lot of fun as it is if well tuned.

 

[talontedtsi1995]

I am not upgrading to any bigger turbo, its my daily driver and don't need anything much bigger, I don't have a aftermarket fpr yet, I am just confused how if i dont give it much gas it holds around 10lbs alright then once i go wot it just cuts out and sputters like crazy, i did a boost leak check already and it all came out okay, my exhaust has a slight warp where it meets the o2 housing but its not noticible i wouldnt think that would effect the performance like this, how would I adjust a aftermarket fpr?

 

[Eastwood95]

550's will work, and the aeromotive FPR kit......

 

[delta448]

How much horsepower are you looking for?

Will you be staying at 15psi max?

-Since you have a 95, you could get your ecu chipped and run some more boost, if you ever decide what size injector you need for your power goals.

There is an injector calculator at the bottom of the 2nd linked page. I believe that it isn't exactly 100% accurate, because every engine is different so BSFC is not really a known number. Just because somebody else's 4G63's BSFC is 0.6 doesn't mean that your 4G63's is. But either way it will get you close.

 

[talontedtsi1995]

yea prob. around 15-16 psi max, thats about what I can get out of the t-28, so my next two purchases will be 550cc fuel injectors and a fpr, thanks alot of the ideas, does it really matter what brand for the injectors or the frp or will any kind pretty much do the job needed? thanks

 

[ivanr4g63]

Most people will tell you their brands are awesome and whatnot... I personally have FIC's (fuel injector clinic) and I have no complaints about them, but for the most part most brands are good when talking on the 550cc~650cc range, people seem to be very picky on brands when chossing a 1000cc racing set of injectors... point beeing, either one will do the job as long as they are in good working order.
As for the A-FPR Aeromotive is simply on fine product, but buschur, fullthrotle, SBR, Extremepsi and other companies have good deal and several brands you might want to look up. make sure you get your FPR with a fuel gauge to it, otherwise you'll make blind adjustments to your base pressure.
And as a future reference, you'll be setting your base fuel pressure with the car fully warmed-up and the vacuum hose disconnected to 37 psi (1G) or 42 psi (2g).

Off topic: I thought the FP T-28 was good for 18~20 max psi... 15psi seems good but not its best is it? unless you're just playing safe and realiable to not blow anything else up then I understand.

 

[talontedtsi1995]

your prob. right about it being able to handle 18-20, I would prob. keep it at 15 for everyday and maybe turn it up to 18 or so for the track and what not, but like I said before, I am running 15 lbs now but it cuts out and sputters bad, thats why I am going to hope the fpr and injectors along with the fuel pump will solve that so my car will run smooth, also, I have a fuel pressure gauge that can be mounted under the hood, will that work as a gauge to adjust it? thanks for all of the advice and suggestions its always good to have more opinions before buying something I dont need, Ill prob. order a fpr first then injectors and see how it will go from that..thanks

 

[DGajre777]

YOU ARE MISSING ONE VERY IMPORTANT POINT...
"Fuel cut has nothing to do your fuel system and your ability to deliver fuel, it isn't triggered by fuel starvation instead it's triggered by too much air."

Read this thread on fuel cut - http://www.dsmtuners.com/forums/showthread.php?t=228330 and pay attention to post 11 and 12 made by Oldman.

Your problem is that you have a boost leak - do a boost leak test!

Fuel cut - as you are describing will not be an issue due to fuel overrrun. The fuel overrun happens at idle RPMs or when you decelerate. If you don't want to get an AFPR, you could swap that 255 pump for a 190pump, which according to FP is good for 400whp.

As for injectors, find some used injectors from an EVO VIII, they should be cheaper than new 550cc injectors.

 

[talontedtsi1995]

I hear it could poss. be my knock sensor? what do you think?