Turbo B6 Problems....

Nomad_69er · Post by **Nomad_69er** » September 12th, 2006, 11:56 am

Well, the turbo is in, the intercooler piping is in, and it runs! The one problem I'm coming accross right now is when I'm at full throttle it bucks and pretty much loses power but if I stay at 1/4 to 1/2 throttle, it can go all the way to 6000 RPM with lots of power. Is this just a tuning issue through the SAFC 2? Do you guys think I need to take out fuel or does this sound like it's running lean??

Thanks for the help!

Bryan

By the way I'm running a FMU and an SAFC2 for tuning and fuel management!

cjthor · Post by **cjthor** » September 12th, 2006, 1:56 pm

How are you tuning? I would definitely NOT go WOT without some type of wideband signal or a dyno tune. Youre asking for trouble.

LooseChangeRacing · September 12th, 2006, 3:29 pm

yeah, should be easy solution, your not getting enough fuel....stock fuel pump? if so, make sure your tuned and if it still doesn't work you need to upgrade the fuel pump

Nomad_69er · Post by **Nomad_69er** » September 12th, 2006, 5:39 pm

I have a Walboro 255lph fuel pump already!

Marlon · Post by **Marlon** » September 12th, 2006, 7:26 pm

sohc or dohc?

BuGS · Post by **BuGS** » September 12th, 2006, 8:37 pm

If you are DOHC then you need to adjust your High Low settings on the SAFCII and the throttle settings. If you are SOHC try unplugging the TPS. That should fix things....

ModMX3 - (Carmaster2005) · September 14th, 2006, 1:42 am

Im pretty sure I read somewhere that you shouldnt use A Fuel Managment Unit (mechanical) with a SAFC electronic unit. Ive heard that they counterbalance each other, causing you to run super rich at full throttle. Allthought im not 100%, im pretty sure your not supposed to use both.

Nomad_69er · Post by **Nomad_69er** » September 14th, 2006, 4:27 pm

It's a DOHC by the way. I'm hopefully throwing a wideband on the car on the weekend but it seems to be running very rich at full throttle. The only other problem is that I don't have different injectors on the car (next year) so the FMU is the only choice for the time being but I dont want to run lean and get detonation.

JWMotorsports · Post by **JWMotorsports** » September 14th, 2006, 9:14 pm

Sounds to me like your leaning out past the point of combustion. Detination sounds like loose change rattling in your pocket. Another thing you can do is pull the spark plugs and look at them. If it is leaning out they'll be a whitish color and the ceramic insulators may have cracks in them if sever detination or small metallic specs on them if its only light detination. If your running so rich its bucking then your also washing the cylinder walls. You can tell if its to rich because the plugs will be covered in black soot. You'll also see a lot of black smoke when it gets to rich. I'd say if your still running your stock injectors then that may be the problem. Double check your sensor settings as per the S-AFC manual. If you have your throttle direction set wrong that would explain it as well. What is the rising rate on your RRFPR? Also, where do you have the boost referance hose for it connected? Using a RRFPR along with a S-AFC isn't a bad thing as long as your injectors are sized right for the fuel pressure your running at peak boost and HP. This could be your problem as well. Fuel volume SEVERLY drops of at high fuel pressures, especially with the Walbro 255 pump. If your running a 10:1 RRFPR w/ a fuel pressure base line of 43psi your fuel pressure at 8lbs of boost will be 123psi which will burn a walbro up in a hurry if it don't melt your engine first. If your looking to run more than 60psi peak fuel pressure look at the Accel DFI 75709 110GPH fuel pump like I have. It can run 75psi continuous and 100psi intermittent and draws very little amperage. The 110GPH (416 LPH) is at 60psi of fuel pressure! Most pumps give their rating at 45psi and SEVERLY drop off starting around 60psi. This is why people have sooooo much trouble fine tuning a car that doesn't have properly sized fuel injectors. My car has 1000cc injectors and idles around 22 psi at idle with a 0" vac. base line of 30psi. By using lower fuel pressures I can use a smaller pump to support the big HP numbers and not drown my engine at idle. As long as your fuel pressure is about the intake manifold the fuel will atomize (unless your fuel injectors have a poor spray path to the intake valves, then you'll need higher pressures).

My recommendation to you is to DITCH the RRFPR (or get a MUCH smaller RRFPR like 2:1 if your running low boost). Your best solution is use a 1:1 RRFPR and bigger injectors sized a bit bigger than your peak power. I HIGHLY recommend the Barry Grant 1:1 RRFPRs! Fuel pressure stays ROCK steady and responds instantly to even the slightest pressure changes! For most people the stock FPR is all you need but I do recommend using a fuel pressure gauge to keep an eye on things. Other good early warning instruments are EGT gauge, Wide Band O2, Oil Pressure, Water Temperature, and of coarse a Boost Gauge.

Nomad_69er · Post by **Nomad_69er** » September 14th, 2006, 10:16 pm

Wow....things I should've know before I started this thing! I believe the unit is a 10:1 RRFPR. The hose from the FMU is connected to the vacuum line from the throttle body to the vacuum chamber (just with a t-fitting). The SAFC I believe is hooked up properly but I will double check just to be sure. The spark plugs were a little bit on the whiter side so I'm going to try to increase the fuel. As for the 1:1 RRFPR, where can I get one? Why can't anyone who's done this live in or near Winnipeg??

Oh well, I guess I'd never know unless I make the mistakes. Any other suggestions or ideas on how to setup the SAFC for the time being? Like what percentages to run at which RPM?
Thanks for all the help guys!!

Bryan

ModMX3 - (Carmaster2005) · September 15th, 2006, 2:35 am

I can tell you from experience DONT RUN LEAN, if thats the case. Expecally on a turbo setup or youll end up installing new pistons like me. and trust me its really hard to locate cheap pistons for the B6. Good luck !

Nomad_69er · Post by **Nomad_69er** » September 15th, 2006, 4:04 pm

On the topic, what size of injectors should I use? I was thinking about throwing in 310cc. Any comments??

Bryan

Marlon · Post by **Marlon** » September 16th, 2006, 12:44 am

what turbo are you using? what psi?

JWMotorsports · Post by **JWMotorsports** » September 17th, 2006, 10:57 pm

As mentioned above...it does definately depend on your turbo.

http://www.rceng.com

RC Engineering has a lovely worksheet to help you out on this. What you need to do is find out the MAX HP your turbo supports. Or if your planning to upgrade to a larger turbo you should go ahead and buy the injectors to support your peak HP you plan to make. If your running the VJ-14 turbo 330cc injectors from a 323 Turbo would be the ticket (test your injectors to see if they are High Impedance or Low Impedance). The are probably High Impedance. I've got a set of 323 Turbo Injectors on hand, if your interested PM me (the injectors I have are High Impedance). On my old VJ-14 setup I used 440cc injectors and a MASSIVE front mount intercooler for that turbo (APEXi Silvia IC).

As far as the S-AFC setup you'll need a Wideband AFR gauge and an EGT gauge for optimal settings. I HIGHLY recommend PLX Devices....I have the M-500 Wireless Data Logging Unit no longer offered. Another good unit is the AEM or NGK Wideband. For EGTs I HIGHLY recommend the Autometer gauges. PLX has a unit that will monitor and datalog both AFRs and EGTs but its pricey...well worth it though.

http://www.plxdevices.com
http://www.corksport.com
http://www.nopionline.com
http://www.jegs.com
http://www.summitracing.com

As for standalones I recommend the Microtech LT-8x available from Corksport. Also I recommend the Haltech systems as well. If you have money to throw around I HIGHLY recommend the Accel DFI Gen 7. The AEM and Motech systems are awsome as well but VERY difficult to completely tune...also VERY pricey!

The Microtech LT-8x is about $800
The PLX M-300 is about $320
The Autometer Ultra Light EGT is about $120

BuGS · Post by **BuGS** » September 18th, 2006, 1:15 am

310 would be good. I think you pretty much have the same setup as Josh. He found with the small b6 with the stock ECU 310's seem to work without a hitch.