A few "carb" turbo ??

[old hat doo]

So I am starting my turbo install and I'm sure I will need a little info/help...

To start, I am wondering what guys do with the vac/pulse port from crankcase?(the one that went to the stock fuel pump) do u cap the port or put a one way check valve on it?

 

[nuttyn01]

port

cap it.

 

[Fack]

Hook it to your blow off valve.

 

[old hat doo]

It's a pulse port, that would not make a BOV function properly.lol

 

[nuttyn01]

Ports

I like to pull the BOV signal from the motor side of the carb. The are blanks on the carbs that work well. I like to pull fuel pressure signal from the pipe. This allows you to set the idle fuel pressure much lower as the fuel pressure will rise with pipe pressure vs utilizing boost pressure alone. This makes pre-boost tuning much easier. You will also want a pressure relief valve somewhere before your pressure solenoid in the rave valve system, if you plan on running higher than 6lbs of boost.

Good luck

When set up correctly they work very well.

 

[brycter]

cap it. pull your signal for where nutty has said. there have been some bovs filling with oil if you pull off the case.
give me a call if I can help in any way.

what parts you slinging?

 

[old hat doo]

Thanks for the tips

It's a boostwurx aerocharger 53 setup on a 04 800ho, with full rebuilt engine and turbo head, power jets, BOV, etc. I will keep you all up to date on my build here, or go and check out the full build on dootalk.....
"04summit/few parts build"

 

[old hat doo]

So you say to cap the vac port. Is there any reason why I couldn't put a inline one-way valve and loop it back to the charge airbox like a PCV valve?

Also wouldn't this PCV idea let any eccesive crankcase pressure blow off instead of blowing the isoflex out of my bearings. Just a thought? let me know what you all think???

Also does anyone know of a turbo blanket that will fit the aero53? I don't wanna melt my lexan panel.

 

[old hat doo]

I did some thinking and realize that the pcv idea would not work pre boost.

Also talked to Jerry @Aerocharger, and found that they sell a heat shield for the 53aero.

 

[old hat doo]

My build is here for those who wanna check it out http://www.dootalk.com/forums/topic/925609-04-summit-few-parts-build/

 

[old hat doo]

So where is the best place to pull 12v power for fuel pump and gauges on the REV chassis?? Looks like I need 12amps or more...

 

[old hat doo]

So I was trying to get this setup tuned when I had an e-clip come off the carb slide mechanism and go through the engine. Waiting for my cylinder to come back from plater and try again.

What I am curious about is what would cause a stumble/ bog on 1cylinder(MAG) just before boost 5000-6000rpm?
If I squeeze throttle from an idle it revs past the stumble and comes onto boost and pulls good, but if I am varying the throttle it can't get past the stumble/bog. Another fella on dootalk seems to have similar problem but he can't even get over 5500rpm.

Carbs:
400mains
22.5 pilots
Needle 2nd clip(leaner) + 0.020" shim
Fuel screws 2 turns open
Powerjets 2 turns open

FYI Power jets are centered in the airbox outlets. Fuel pressure reference from vacuum side of carb slides, idle fuel pressure 3psi.

 

[swrev]

I'd first try powerjets all the way off to eliminate the tubes being to long as your starting to build boost and fuel pressure. If no difference in stumble drop pilot jet size. Most carbs are stock or smaller for turbo apps. Start w/ 17.5 or less. Most likely your sled is just going extremely rich during the pilot, main transition. As far as one cylinder being more prone to stumble, could be just a weird coincidence unless the one that wasn't stumbling is also the one that the clip came off of as that would essentially keep your needle seated further and lean out the mid. How fresh are you caps and wires? Bad/weak spark creates some weird issues also. I'm replacing wires and coil on my turbo, had some nice melting going on when a wire came loose from the coil.

 

[old hat doo]

I replaced the plug caps and wires early last season, has good clean spark at the plugs.

I had a 17.5 pilot in originally but it made my engine idle really high so went back to 22.5(had 22.5 N/A).

Even before the slide mechanism came apart it had the 1cyl stumble at 5000-6000rpm. I tried power jets in all sorts of positions but it only moved what rpm it would stumble at, no real improvement, needle position seemed to have the same effect.
I'm starting to think that I have my carb floats out of sync or a weak needle seat that is bypassing when fuel pressure starts to rise??

 

[brycter]

put in 15 pilot close. make sure your only seeing 3 psi of fuel pressure at idle. make sure your bellows have not blown apart. make sure your pipe is not blown apart at the seams

 

[old hat doo]

Thanks, I tried 17.5 pilots from the start and couldn't get my engine to idle down. Was over 16 on the wideband, put 22.5 back in now it's 14afr and idles good.
Just checked, rebuilt, and glued rave bellows after first time I let off the throttle with boost and they blew apart.

Gonna pull pipe and take a look for exhaust leaks tonight...

 

[swrev]

Didn't look at complete build, but your DPM is undone isn't it?

 

[old hat doo]

Yes, DPM is gone. Boost reference on the carb ports that were used for DPM.

 

[old hat doo]

A few pics of my build/setup..

 

[swrev]

Got to thinking about only times I've had throttle transition issues. You've eliminated spark and power valver, I'm assuming you double checked when taking apart. Only other time was directly related to carb reference. Had a hose basically floating over a nipple off the air box. I actually ended up getting rid of all the hosing that looks like the stuff you are using and run some small translucent fuel hose. Easier to get a solid connection to the barb fittings and then secured with a small zip tie. If you've been test fitting, could easily just be a leak at one of the fittings. I hope it ends up being that simple because nothing else is really coming to mind. I've split pipe, blown boots, and even ran after sticking a piston and those have never caused a stumble. About has to be a boost reference issue.