Throttle chop poll! everyone please respond.

[hot rod rooster]

i would like to know

1. what kit everyone is running, brand and front or rear

2. what BOV/BOVS you are running

3. how bad the throttle chop is.

4. if you did anything that made your chop alot better.

thanks in advance for your time!!!!!!!!

 

[Turbo Tim]

On my bender the throttle chop was fixed with lowering the float level , it was never bad and I didn't have a blowoff valve.This year I have one of the powderlites BOV 's on it and it still does fine , and no more compressor stall

My cpr turbo never had a blowoff valve and never had a throttle chop problem .This year it also has a Powderlites bov .

 

[hot rod rooster]

what did dave charge for the bov?

what are your float levels at?

 

[woodsrider]

Bender rear mt, 14# boost, TurboXS BOV w/4 coils cut from spring, lowered needles 4 nylon shims, 140 mains, 40 pilot, 3 out on pilot screw, 600 pitot tube jet, no throttle chop. 6000ft.+ elevation.

 

[givemeaboost]

I have a Bosch blowoff valve . I think it's what Powderlights is selling.You can get one at any VW dealer or maybe even the parts stores. I paid $42 for mine and I hooked it on the end of the intercooler and it never even fazed the throttle chop problem but it does let it go back to high boost better and sounds cool too. I can go from wide open to off the gas and back to wide open but can't let off and try to go easy or it will die. Funny thing though, when it does this and dies I just hit the key and it fires right up and takes off like nothing happened,Ken.

 

[hot rod rooster]

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givemeaboost, my sled will do the same thing, when it does die i can just turn the key and it fires right up too! i am going to drop to 15 pilots and the feul screws to 1-1.5 turns and see if that helps!

 

[powderlites]

throttle chop

Blowoff valve does two things!
one is it lets turbo keep spooled up for better throttle response keeps turbo stalling under hard throttle chop.
When blowoff valve is installed ahead of float vents pressure hose and not in the end of intercooler so it won't flood under throttle chop.

On our turbo kit blowoff valve is open at idle so turbo is spooled up and ready for boost. No lag !
Vector can idle at 1500 RPM and can still race with the best of sleds out there.
Blowoff valve oepns at 5 to 6 inches vaccum!!!
Check the other ones and you may find out only open when chopping throttle at higher vaccum and boost to help push open!

I have made and sold over 50 blowoff valves for MC,CPR guys this season.
Our Apex has all new designed blowoff valve that flows more then double of bosch or mitshibushi ones used.
As for Apex supercharger running with our turbo kit was a joke and everyone there agree the EFI programing was way off on supercharger.
20 sleds lengths in short run is not even close.

 

[rideblue]

Boondocker side mount
Bosch BOV
Float level at 15 mm
Fuel pressure regulator tee'd into intake boots and set at 4 psi.
Only problem with throttle chop is when nose is straight up and go from WOT to fully closed. Going to lower floats to 16mm and try agian sunday and monday.

 

[Freak]

Dallas are you having chop problem? I thought you cleared it up with the HKS?

MCX rear mount

Mitsu BOV

Chop used to be really bad. Moved the equallizer line to the vaccum side of ALL carbs and improved chop by about 80%

 

[sledheadgeorge]

1. MCX rear mount.
2. Turbo XS with a few coils cut from spring.
3. Non existant.
4. Venting all vaccum lines together and BOV solved it.

I have one of the original MCX rear mount kits that came with no BOV.

 

[hot rod rooster]

freak the chop just showed up out in the hills. it was almost non existant here at home (2000 ft) but out there in the moist thin air it was pretty bad. i think we may have tracked it down to pilots and air screws. i think i am going to loosen off my BOV's too.

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thanks to everyone who is replying to the poll! it is a big help!!

rooster

 

[Feetsbig]

MCX rear,BOV on side of intercooler,added a bosch in charge tube hose,lowered floats,plumbed to carb boots,much better

 

[rxrider]

i would like to know

1. what kit everyone is running, brand and front or rear

MCXpress rear 16T Mitsu.

2. what BOV/BOVS you are running

Mitsubishi mounted on left side of Intercooler vented to carb boot 1 and 4. I will try to vent to all four.

3. how bad the throttle chop is.

It's there. Sled died if I let off throttle at WOT and full boost. When going uphill with skis in the air or doing wheelies then when I'm coming down hard it does some coffin and spittin then clears up.

4. if you did anything that made your chop alot better.

I have raised idle rpms to 1800-1900, it is not dying on me anymore. MCXpress recommends removing the Mitsu BOV on the side of intercooler and plug that hole because having it too close to the carbs is causing flooding of the carbs, the BOV can't react fast enough on the raised pressure when too close to carbs. Next they say is to add a BOV right in front of the intercooler. A friend of mine has this done to his sled and it's much better now.

thanks in advance for your time!!!!!!!!

 

[hot rod rooster]

this is all great info guys thanks for the help!