A few Turbo CIS questions

[pjv911]

3-4 weeks ago I got my 82`sc up and running with a 92` C2 3.3 CIS turbo engine. It runs great but im still looking to make sure I made no mistakes along the way. So I have a few questions for you guys.

#1 I bought both turbo fuel pumps used here from a fellow pelican. My shut down fuel psi drops below spec within 5 minutes. Spec calls for 20 minutes. Im experiencing a hard warm restart after 15 minutes or so. I pulled out my accumulator which was a 005 version and checked it. The diaphram is good. However I found out that the correct accumulator is a 031 and since I had a good one I put it in. Also used the larger S line that goes to the filter. Well the problem still persists. Next is to replace the check valve in the pump/s .
My question here is... Are both pumps supposed to have check valves or just one. Also which one if not both ?


#2 My engine came factory equiped with an air pump/air injection system which puts fresh air into the exhaust port.
I removed the entire system except for the air injectors/lines/and check valve. My question is will the check valve still allow air into the exhaust ports ? Should I find plugs ? Where can I get them ? The reason for concern is that between every shift (even when driving very easy) Im experiencing loud backfiring out the aftermarket fabspeed muffler. Funny thing is the problem just got much worse today after installing the correct turbo accumulator and a new f/filter .

#3 Which causes more backfire/flames when decelerating ? Is it rich or lean that makes it worse.
For what its worth my dead head fuel psi is 98 lbs and warm running psi is 65 psi . Both are correct spec for this engine.

#4 On a cold morning start my controlled fuel psi increases from about 45psi to 65psi just as it is specified in the book. It takes less than 2 minutes to get there. Is this too fast ? The book does not mention time frame for refference.
Also I recall reading that its a lower control head psi that gives a richer condition due to the metering plate moving easier. Is this correct info ?

#5 Lastly (for now) Im very interested to push the boost up to 1 bar. Im currently running it safely at .6 bar untill all fuel issues are secured. I have a Andale Enrichment setup but think its kinda primative and will add more room for problems. Should I list it on ebay and get the Imagine Auto fuel dist mod done ? I spoke with them today and its only $540. Has anyone used this service before ? Any input ?

Overall the car is running like a scalled dog with the stock 320hp in a 2400lbs car and a modified ratio shortened G50 5spd . For the record I just yesterday beat a friends 2006 ZO6 vette from 35-85mph by a car length. Yes he was embarressed and said he had the A/C on.
Im looking to get another 75hp or so. Can this be done with 1 bar and proper fuel mixture ?

Sorry about all the questions. I hope some of you will take the time to offer me advice. More than one members responce is always better. This is my first 911 turbo experience so its kinda new to me.
I should also add that my engine came from Brumos Porsche in fla
It was to be raced back in 92` but the 3.6t had just become available so it has sat on the shelve since. Its basically a complete brand new stock engine. It is labeled all over the engine and computors as "super car" Anyone know what that meant ? And I did run 2 bottles of techron through it already. In short the engine is stock and mechanically sound.

Thanks in advance

Kurt Williams

[mb911]

sorry no good answers for you but have heard the IA system works great. I also would guess the pump closest to the tank has the check valve.

Man when do you sleep. and for that matter nakita. You east coasters are go getters. saw the 914-6 2 man I am jealous

[pjv911]

Originally posted by mb911


Man when do you sleep. and for that matter nakita. You east coasters are go getters. saw the 914-6 2 man I am jealous

I think Nikita works and thinks Porsche 24 hrs a day. And somewhere in between manages to sell mortgages and keep his wife happy.

Me , I do all of my own work but also have hired help to do the dirty stuff. Owning my own repar facility is an added bonus.
I find it easier to buy things then it is to install them . Time is always limited.

Kurt Williams

[mb911]

let me know if you want out of the 914-6 I would find a way if it were. I could trade you a bunch of mufflers

[mdj930]

I am still breaking my engine in that was rebuilt at IA. Stephen is a great guy and I am very happy with the work they did.

Mike

[pjv911]

Anybody care to help ?

[Paulporsche]

Usually popping out the exhaust on a NA car means the mixture is too rich, but it may be different for a turbo. I remember turbos from the turbo F1 and 935 era used to pop that way because they were set rich, and because the was excess fuel (because of the wastegate) in the system which would ignite and shoot flames and loud noises out the tailpipe. Maybe since you removed that air injection, the mix, at least @ that point, is too rich.

At least this will bump it up for you.

[rsrfan]

Kurt,
try posting this on the Rennlist forums. There is a lot of turbo knowledge over there.

JP

[pjv911]

I tried Rennlist. Not one answer. Kinda like here. I cant believe knowone has helped yet. At least on some of the questions.

Kurt Williams

[mb911]

as already mentioned poping out the tail pipe typically means rich condition but could also mean something as simple as loose exhaust flange etc. I am sure you already know that though.

I would say that the air injection pump should be plugged as well along with all the ports if you are not using it. But again you probably already know that.

I can tell you that My friends 930 does not pop or shoot flames at all but his is a stock 79 With minor upgrade such as better headers etc.

My turbo does not pop either but again a poor comparison as it is efi and was NA turned to turbo

[9dreizig]

My turbo doesn't pop.. My buddies was a couple of weeks ago and it was a cylinder gone bad.
75 HP is alot of ponies for just moving to 1 bar and I would be VERY leary of doing that until I found out how the A/F was running. What about a larger turbo and intercooler ?
There are enough turbo geeks here to help, give it a day or two...

[slow&rusty]

Kurt - Go back to the Rennlist topic, both myself and Stephen from Imagine have replied to some of your questions.
Yasin

[pjv911]

Originally posted by slow&rusty
Kurt - Go back to the Rennlist topic, both myself and Stephen from Imagine have replied to some of your questions.
Yasin

Thanks I will take a look see.

MB, I am fairly certain that since its a 965 engine with the big intercooler, factory k27 turbo and low factory boost setting that it will respond nicely to an additional .4 bar . Doughtful I will get 75hp more but maybe with some other mild mods.

Ok let me go read the rennlist responce.

Kurt Williams

[mb911]

Originally posted by pjv911
Thanks I will take a look see.

MB, I am fairly certain that since its a 965 engine with the big intercooler, factory k27 turbo and low factory boost setting that it will respond nicely to an additional .4 bar . Doughtful I will get 75hp more but maybe with some other mild mods.

Ok let me go read the rennlist responce.

Kurt Williams

Wait that was not me suggesting that

[pjv911]

Opps. Sorry about that. Anyway Steven said the same thing too so its not wrong.

Kurt Williams