ECU+ dyno pulls have me anywhere from 335-350. You saying that yours hits around 99% and saying it has 370hp makes me think that the numbers aren't lying, and that maybe we need upgraded injectors sooner then people originally thought.

 

Bump for more opinions.

 

Injectors can be run flat-out at 100%. Usually what happens is you end up losing control of the injectors and the car starts richening out. With the stockers on our dyno (keeping in mind every dyno is different) on 91 pump gas they start maxxing out close to 280whp. Running a walbro pump is an interim solution as the fuel pressure is bumped slightly over stock thus helping the situation. That said a $350 set of injectors is always a good investment for the Stage 2+ guys.

Helix injectors are in stock (hint hint)

Cheers,

Gary
Gruppe-S

 

We have seen injector duties around 90-95% with Cams mod. I would recommend people to upgrade their injectors to 720cc when they are doing their cams...especially for the track guys when they are always in the upper rpm range. It's a cheap safety against over working the injectors.

On a side note, Helix just came out with their 720cc and we have tested them with great results. It idles like stock and very easy to tune. For just $365, you can have much better and capable injectors for your power needs.

More info on the Helix injectors:

Thanks,
Tom

 

Something is seriously wack with your flash if you have to add 20+ fuel with C-16 race gas. That is a big big reason why you are maxing out your fuel injectors. I am surpised you haven't hit fuel cut.

And 14 degrees timing at 7k rpm? Yucky.

You have the ECU + now, why have a flashed ecu?

 

Gruppe-S thanks for the tip, I purchased a set of injectors (780) from a vendor here used, I have and do purchase from Gruppe-S whenever possible (and cheapest) and I'll probably be purchasing a turbo kit through you guys come spring. I appreciate your help, I'm not all about pumping up vendors, but you guys have provided me and my friend damn good service thus far, keep it up.


I don't have to add 20% fuel with race gas, I was on my pump map and was tweeking it for the c-16 when the laptop died 100 miles from home. I was thinking 25psi@12or14% fuel from 4250rpm to redline would have done the trick for a rough map.

What kind of timing advance are you seeing at 7k?

I have the flashed ecu because I'm too lazy to have it shipped out and flashed back to stock when I can just manipulate the ECU+ to do what I want it to do.

 

On a 3rd gear pull, I see approx 20-22 degrees, keep in mind however I am using 720cc injectors. Although, with my stock injectors I saw about 18 degrees.

2nd gear I see about 23.

 

This software is using a wideband 02 ? I can assure you .. that your car wasnt tuned so you would have to add 20% fuel to get into the 11's ... for afr. Every car i tune sits around 11.2 - 11.6 with a wideband ..

Mark
Turbotrix

 

I am having the same problems and i have Autronic and stock cams..... I hit 97% at about 6k rpm and it stays there I added more fuel but it stayed at 97%. so i parked the car waiting on a fuel pressure gauge so i can check the pressure the pump is sending. Im thinking its either the FPR or the fuel pump possably not switching to high mode. I also have a walbro 255

 

Yeah, it's using a wideband. I saw you tune it with my own eyes, I saw the wideband read 11.4ish. The flash does seem wierd to me, but it might just be the boost or the boost controller or something else. I know you were having problems with fuel when you tuned it, you said something to the effect of "Man I have to basically tune this thing like it has 660s".

Maybe the boost gauge is reading incorrectly? I'm getting a map sensor soon, and I'll feel like an *** if it ends up being because my boost gauge is broke.

 

I have never seen a stock turboed car run out of injector. Unless you tune is just plain out whacked, you are fine on your mods without bigger injectors. Bigger injectors on stock turbos is one on the biggest wastes of money I see on Evos.

 

I can send you some logs if you like. It's very obvious when the injectors max out - the a/f drops from mid 11's to mid 10's and timing stops advancing. I hit 85%dc at ~5800 rpm at a relatively lean 11.8:1 and it just goes downhill from there.

 

If you are at 109.5 mph in the 1/4, I doubt that your injectors are maxed out. With stock injectors, I managed 115mph in the 1/4mile AND my car (driven by Chronohunter) ran a 1:26.2 at the Streets of Willow Springs on the exact same map and tune. That 1:26.2 was part of a track day where my car saw over an hour of total track time.

Also, there are countless Evo 8's doing 12 flats in the 1/4 at or around 113-114 on stock injectors. My guess is that your logs calculations are too conservative and/or your tune needs work.

My understanding of maxed out injectors is that you will see an abrupt rich spike in your AFRs, followed by a straight horizontal line going lean.

 

IF you need to know what size injectors you need just do a brake specific fuel consumption. The equation goes as follows:
Ok lets say that your evo has 300 horsepower. Now lets just say that you are using a BSFC of .55 ( Brake specific fuel can vary depending on the volumetric efficeny of your motor, all motors being a little different we will use .55)
So then it goes like this
300x.55=165Lbs/hr
165/4(being the amount of injectors)=41.25
So the injector needs to be at least a 41 pund injector. Now assuming this is all correct, this is the maximum duty cycle that a the injector will see. Since we do not want to be maxing the injector out, usually I add about 20% on to the final answer so to have some sort of safety margin.
Now if you want to get to cc's then all you have to do is take 41.25x10.2=420.75. This being the max lets go ahead and add 20 % so that our injector duty cycle will be about a safe 80 percent, and you are coming up with only about a 505 cc injector, so if you need to figure injector size out with another horsepower, just plug the HP number as as the first variable and then bam you are good to go. Hope this helps some of you. Have a good day everyone
Mitch

 

My low mph in the 1/4 is an issue of timing, and why I switched from the emanage to the ECU+. I was seeing less than 15* of timing through the traps. I can't comment on the willow times, and I'm not sure how it realates to idc at redline anyway. The tune obviously needs work the unit has only been in the car for a couple of weeks and it's been snowing here.

I'm quite aware of the general consensus that stock turbo'd cars don't need injectors, but I can't ignore the numbers I'm seeing and I'm also unwilling to run my car at 90%+ idc. My a/f curve does show an abrupt rich spike and could go lean if I wasn't out of rpm.