550cc injectors and the evo 16g

[Steve93Talon]

Theres a local guy in the pa area on a 20g going low low 11s on 550s with a 20g tort20g or something is his name on here

Tort went 11.05 @ 123 on 550s. This is on a 1G at 37psi base fuel pressure. With race gas, you can take it alot further on small injectors.

 

[SFRacingGST]

not really sure why my car ran as it did with the 650's. I had alot of work done at PRUVEN and i had given them 650's with it. When i got the car back, it ran like crap and missfired like it was its job. Called up dan at pruven to see what the deal was and he told me that the 650's was my problem. I bought some rc 550's and they did the trick. after reading this thread though it made me think more that pruven didn't know what was up. My car should have ran fine with the 650. I am saving the 650's that i had incase i decide to go bigger than the evo 16g.

 

[pickens]

650cc and AFC w/out chip compensation will lead to the car bucking quite violently at part throttle. Some think its a misfire, some think its compressor surge, but in reality its the amount of airflow that is being hidden from the ecu. The ecu doesn't know what the engine is really doing to effectively control it at part throttle. Full throttle you wont have a problem, just part throttle when building any positive boost. It gets annoying because you either have to baby the car or floor it (no inbetween), and you cant use cruise control on roads w/ any slight hills that cause boost pressure to go positive.

Solutions: Chip compensation or DSMlink

 

[spyderturbo007]

650cc and AFC w/out chip compensation will lead to the car bucking quite violently at part throttle.

Do you have any 1st hand experience with 650's and a SAFC-II

I have no problems with 650's and an SAFC-II. Also, if I remember correctly CanadianTSI is also running 650's and a SAFC-II with no problems.

Being FWD I can only run part throttle durning a launch and have had no problems with bucking. So I don't see why you are saying it can't be done. WTF

 

[pickens]

Let me clarify...part throttle as in day-to-day driving like when you need to accelerate moderately to either pass, merge, etc. Accelerate at about 35-45% throttle while building any positive boost pressure and the ecu will let you know it doesn't appreciate. Now, launching at part throttle isa totally different scenario because a completely different load is placed on the engine causing the ecu to respond differently. I never had a problem launching either, FWIW.

Now perhaps, you can band-aide the problem by playing w/ switch over points and have the AFC not hide so much airflow at certain points. I tried for a year unsuccessfully, but even if I did the car would still not run as intended during part throttle (day-to-day) acceleration scenarios.

And yes, I was running an SAFC-II for over two years w/ 550s, 650s, 14bs, 16gs, and 50 trim combinations over that two years. Trust me from experience when I say, the difference between a straight AFC and chip comp/Dsm link is night and day in terms of drivabilty for 650s.

 

[spyderturbo007]

Maybe my car is special, but I have absolutely none of the problems that you describe, regardless of my throttle position, load, boost pressure, etc.

Weird.

 

[pickens]

Post your AFC settings for low, high, and crossover positions.

 

[GVR4592]

I've also ran 650's and safc with no problems as have thousands of other people. The only problem I've encountered with large injectors and safc is to much timing advance. I've ran 750's and safc before with no bucking, hesitating, or anything.

 

[spyderturbo007]

Post your AFC settings for low, high, and crossover positions.

I would be more than happy to, but she is in storage for the winter. Washed, waxed, no battery, covered, etc. So I really can't get them for you.

I can, however, make a generaliziation from what I remember.

Lo throttle point = 30%

Hi throttle point = 80%

Low throttle correction = All are around the -12 to -14% range.

After my dyno WBO2 tune these were the hi throttle settings

1k = -23%
2k = -23%
3k = -22%
4k = -26%
4.6k = -27%
5k = -34%
5.4k = -33%
6k = -33%
7k = -33%

The company that did the dyno tuning was clueless and I was having my timing pulled all over the place, so I have made some adjustments since then. But those numbers are probably close to the values now.

 

[92GSXBaltimore]

depending on how much boost you are planning on running, you should be fine with the 550's. Incrementally turn your boost up and tune with your AFC (and a borrowed logger). Check your IDC and if your nearing +95%, turn your base pressure up a couple pounds. Re-tune, log, repeat....I just wouldn't go past ~47ish pounds base without at least a chip.

p.s. your timing might be getting pulled b/c of a intake(boost) leak.

 

[pickens]

Those seetings look nearly identical to what I had. Perhaps you do have a special car.

I'd bet the reason why timing was getting pulled was due to knock. The ecu was probably trying to advance timing pretty aggresively which leads to knock early on. I had the same problem and ended running my AFC richer than I liked to slow down the timing advance. my high were in the high -20s at one point. Even then, the car was never consistent from run to run. When I first connected the DSMlink I set the initial settings based on the AFC compensation I had. And man, I was surprised at how janky the engine was running w/ an AFC like tune. How'd that old song amazing grace go...."I once was blind, but now I see". .

 

[GVR4592]

I'm not trying to be a dick but I think your car is the special one. I've experienced the bucking you are talking about but I was always able to tune it out. It was usually from being to rich or from a boost leak. That's weird that you weren't able to tune it so it wouldnt do that. I do agree with you about going from safc to dsmlink it's a huge improvement.

Those safc setting don't look right to me. Pulling more fuel in the midrange is just the opposite of how it is supposed to be. Generally you need more fuel where your engine is making its peak torque, on our cars thats usually between 3800-5500. Which is right where those safc setting lean out the a/f. What was the a/f ratio on those dyno runs.

 

[NewB2dsm]

depending on how much boost you are planning on running, you should be fine with the 550's. Incrementally turn your boost up and tune with your AFC (and a borrowed logger). Check your IDC and if your nearing +95%, turn your base pressure up a couple pounds. Re-tune, log, repeat....I just wouldn't go past ~47ish pounds base without at least a chip.

p.s. your timing might be getting pulled b/c of a intake(boost) leak.

I will be pushing this turbo to its limits. I have 650cc injectors and will be getting my eprom chip here shortly.

 

[CanadianTSi]

Wouldn't happen to be venting your BOV would you Pickens?

I can sit there at like 50% throttle in any gear and hold 5-10psi and accelerate to redline without any bucking.

 

[pickens]

Of course I'm not venting my bov. Hey, if the AFC is working for you then great, it didn't for me and now I swear by DSMlink. Just by switching to DSMlink I picked up 3 MPH in the 1/8 mile and that was w/out knock on a mild tune. Gotta love this stuff.

 

[spyderturbo007]

Those safc setting don't look right to me.

Are you talking about mine.

They have been adjusted since my dyno tune (AFR = 11.3:1).

Don't worry about me, I'm good at tuning.

 

[Spoolin4Ever]

Are you talking about mine.

They have been adjusted since my dyno tune (AFR = 11.3:1).

Don't worry about me, I'm good at tuning.

Just curious; are you still at about 240 WHP and running 650 CC injectors?

I'm trying to come up with a cost-effective way to hit 300 HP. I was thinking of going with 550's, and an EVO FP, and EVO or 550 injectors, and SAFC2, and an EVO3 16G. Looking at your mods and you're only at 241 WHP, makes me wonder if this is a reasonable expectation..?