Hey guys wondering if some one can help. I have a 13 b t11 streetport w/ rotaryshack oer sidedraft carb and hybrid turbo. I have a holley blue ful pump w/ a mallory fuel reg. Part #4309
Well when I start it my wide band reads in between 11 and 12 but when I drive it, it jumps up to 15, 16. I have my fuel pressure set at 5psi and when I rev it up it does rise so I have no idea what it could be.so if any one can help please do .thanks

 

I'm a turbo newb, and Have yet to have a caburated turbo, but soon my FB will be boosted. I think you may need another psi or 2 of fuel pressure. I know the racing beat holly recomends 6PSI on NA 12A's. Also I'm not sure if this is nessassary but maybe a rising rate FPR would help some?

 

air fuel guages will only work on 3rd gear at WOT with a load,its never going to be acurate at idle

 

Well I did drive it and right about 3000rpms it leans out .oh and by the way its a fresh rebuild too so I'm trying not to boost

 

ill be in the same boat as u soon. u got any pix of ur hybrid turbo?

 

he has a wideband

 

the problem may be in the carburetor's jetting. You might need to fine tune by changing the jetting.

 

Are you using a Rising Rate FPR or just a regular style? your fuel preasure should be going up 1psi/per psi of boost iirc.

if you are using an RRFPR, make sure that the tube reading the boost isn't kinked or clogged.

it could also be the Jets as TheNeanderthol said. Try tuning the carb a bit more, you'll have to do it as you drive as you need load on the motor to properly set the fuel. sitting still will not give you accurate fueling under load.

(Please keep in mind my turbo knowledge is mainly with VW Diesel engines so I may be off on some things)

 

JETS!! and possibly emulsion tube... also check your float level....

 

you need an rrfpr and alot of tuning possibly jetting.

 

The 4309 is not a rising rate fpr.

 

holley blue is not enough either. you need a fuel injection fuel pump. most guys are using MSD at a minimum

 

+1 on pump being the problem. I'm running with a gslse pump Robert sold me... he may have more ping him.

Dont go boost happy with those afr's... the rear plate in my pic cracked boosting 12 psi on 1 bad detonation... but I didnt get my carb prepped from Robert and was tunning the mikuni which is more of a pain than the webber.

 

it is a raising rate, i had one and that is the only reason i bought it
http://www.summitracing.com/parts/MAA-4309

 

what are you using to set your pressure with, it isnt a cheapy pressure gauge is it?

 

+1

Joel, you got the fpr working,now get the right fuel pump

 

Well I replaced the pump with an efi walbro and its doing the same thing so what ealse can I do mabe elimnate the fuel filter . Right now I'm stuck so please help....

 

Simplest way is to run a low pressure/high volume pump (Holley 110) from the tank to a surge tank, then your Walbro from the surge tank to the fpr with the return line feeding back to the surge tank and a return line at the top of the surge tank back to the main tank.

Even with all that, I wouldn't run the main tank less than 1/3 full if you're doing hard left hand cornering or long sweepers.

If I can find a place to work, I can mod an S3 tank for you. PM me if interested.

 

what are you using to chk your fuel pressure?

 

What size surge tank do I need and were would I mount it. Is ther a write up on this. Can you pm it to thanks

 

I'm useing a feul pressure gauge that monts on my fpr

 

if you have a full tank of gas and you are still leaning out I wouldnt think that switching the tank would solve the immediate issue.

Place your fpg where you can watch it as you hit boost (I have mine running through the groved panel where the wipers are mounted).

If it raises, then start looking for boost leaks.

If you have no boost leaks then tune your jets / tubes.

If you got the carb from Robert I am sure he can give you advise.

BTW I have my fpr set base to 7.5 psi but I'm running a stock port 12A now.

Also are you running an MSD box? Is it boggin or anything?

Has it allways done this since install or did it just start happening?

 

Don't recall if there's any kind of write up. Surge tanks have been mounted anywhere from the frame rail where the cut and check valve is to the engine bay. 1 to 1-1/2 qt is a good size for a surge tank. The Aussies seem to run them more than we do so you might do a search on Ausrotary.com.

 

I don't have a msd box I have a stock ignition with a locked dizzy and its alway done this since I've installed it

 

Well ill look into it and ill try to do some thing this weekend or if I have some free time during the week.
I want to say thanks to everyone that's helping fix this head ache and money pit but really thanks .Joel