Turbos and BlowThru Carbs

[A/Fuel]

Re: Turbos and BlowThru Carbs

I'm still not so clear on what it takes to make a blow-throu carb....

[seanm]

Re: Turbos and BlowThru Carbs

http://www.hangar18fabrication.com/blowthru.html

Read the link. It covers the basics to making a carb work in blow-through.

[BangShiftChad]

Re: Turbos and BlowThru Carbs

I've never built a blow through carb, so I don't know the specifics, but I do know the box works good.

They aren't cheap, but somebody could build one pretty easy.

They use double seals and bearings for the linkage which is the only "trick" part to them and you could build your own pretty easily I think.

[milner351]

Re: Turbos and BlowThru Carbs

The modifications outlined in the hangar18 threads are not complex or expensive.... but they seem to be the bare bones minimum for a blow through.

The $1350 ethanol blow through ready set up on Eric's page is a very neat looking piece - but - only required if your also running E85 with your boost - which is interesting as hell to me!

[horsewidower]

Re: Turbos and BlowThru Carbs

E85 and boost are made for each other.

[Memphis]

Re: Turbos and BlowThru Carbs

Apropos of nothing, but Morris & Co. had that 2000 HP Pro charger blown 572 BBC wagon at the '05 DW and it was completely sick. It sounded like a TF car echoing of the trees before it pushed a rod out of the block.

I believe this is the beast you speak of

http://www.youtube.com/watch?v=FoySWrfJn6o

[CDMBill]

Re: Turbos and BlowThru Carbs

That's the one. 7.51 @ 190 who wheee!

[Bamfster]

Re: Turbos and BlowThru Carbs

WOW!....That's cool

[Huskinhano]

Re: Turbos and BlowThru Carbs

I've often thought it would be cool to build a cheap blow through system as well. Generally what I've read is that you can runner a smaller carb mostly because you're blowing a lot more air through it then you could suck through it. Next is to run annular booster carb instead of a straight or down leg booster because it meters the air better. Next is to drill open up the power valve circuits. This way you can run saner jetting size for cruising while allowing the power valve circuit to flow the additional fuel when boosted.

There was a guy in NE PA who built a really cheap blow through dual turbo on a late 80's Tbird with a junk yard 351W and Tbird turbos. For fuel enrichment he had a really slick and cheap set up. Two fuel injectors off a Mustang triggered by a pressure switch plumbed into the inlet tubing to the carb.

Found the link http://members.jasnetworks.net/mjsitar/toohighpsi/

[TC]

Re: Turbos and BlowThru Carbs

I've often thought it would be cool to build a cheap blow through system as well. Generally what I've read is that you can runner a smaller carb mostly because you're blowing a lot more air through it then you could suck through it. Next is to run annular booster carb instead of a straight or down leg booster because it meters the air better. Next is to drill open up the power valve circuits. This way you can run saner jetting size for cruising while allowing the power valve circuit to flow the additional fuel when boosted.

There was a guy in NE PA who built a really cheap blow through dual turbo on a late 80's Tbird with a junk yard 351W and Tbird turbos. For fuel enrichment he had a really slick and cheap set up. Two fuel injectors off a Mustang triggered by a pressure switch plumbed into the inlet tubing to the carb.

Found the link http://members.jasnetworks.net/mjsitar/toohighpsi/

On Ebay they have Demon BlowThru carbs for 5-600 dollars, just pull out of the box, bolt on and go(no drilling required). ;) An 850 annular runs $600, and that is the size of the carb that was in that BlowThru article in CC. I'm figuring in a blow thru setup the more fuel available the better.

[Huskinhano]

Re: Turbos and BlowThru Carbs

I've often thought it would be cool to build a cheap blow through system as well. Generally what I've read is that you can runner a smaller carb mostly because you're blowing a lot more air through it then you could suck through it. Next is to run annular booster carb instead of a straight or down leg booster because it meters the air better. Next is to drill open up the power valve circuits. This way you can run saner jetting size for cruising while allowing the power valve circuit to flow the additional fuel when boosted.

There was a guy in NE PA who built a really cheap blow through dual turbo on a late 80's Tbird with a junk yard 351W and Tbird turbos. For fuel enrichment he had a really slick and cheap set up. Two fuel injectors off a Mustang triggered by a pressure switch plumbed into the inlet tubing to the carb.

Found the link http://members.jasnetworks.net/mjsitar/toohighpsi/

On Ebay they have Demon BlowThru carbs for 5-600 dollars, just pull out of the box, bolt on and go(no drilling required). ;) An 850 annular runs $600, and that is the size of the carb that was in that BlowThru article in CC. I'm figuring in a blow thru setup the more fuel available the better.

Yeah, I'm with you. I think I'd pony up for a built blow through also.

[seanm]

Re: Turbos and BlowThru Carbs

I doubt any blow through is going to be a perfect bolt on and go. They will all need some fine tuning. Even a custom built one might need some work.

Unless they have made changes the BG blow through Demons tend to run on the lean side and need some jetting, air bleed changes and the pvcr drilled to get closer to a better tune. especially if you run over 10 psi. They are mass produced carbs after all.

[miketblsr]

Re: Turbos and BlowThru Carbs

I've often thought it would be cool to build a cheap blow through system as well. Generally what I've read is that you can runner a smaller carb mostly because you're blowing a lot more air through it then you could suck through it. Next is to run annular booster carb instead of a straight or down leg booster because it meters the air better. Next is to drill open up the power valve circuits. This way you can run saner jetting size for cruising while allowing the power valve circuit to flow the additional fuel when boosted.

There was a guy in NE PA who built a really cheap blow through dual turbo on a late 80's Tbird with a junk yard 351W and Tbird turbos. For fuel enrichment he had a really slick and cheap set up. Two fuel injectors off a Mustang triggered by a pressure switch plumbed into the inlet tubing to the carb.

Found the link http://members.jasnetworks.net/mjsitar/toohighpsi/

On Ebay they have Demon BlowThru carbs for 5-600 dollars, just pull out of the box, bolt on and go(no drilling required). ;) An 850 annular runs $600, and that is the size of the carb that was in that BlowThru article in CC. I'm figuring in a blow thru setup the more fuel available the better.

I hate to tell you this but the demon B/T carbs are junk!!!!! You will spend more time one the dyno trying to get them to work right then they are worth. You really need to read the turbo forum and see exactly what it takes to make it all work. If you are not going to use a box its better to spend the cash on the CSU or c&s carbs.

Here is the link to the turbo forum see the carb section

http://www.theturboforums.com/smf/index.php

[SpiderGearsMan]

Re: Turbos and BlowThru Carbs

EVERYBODY DUMPING ON BARRY GRANT AGAIN .......

[Eric68]

Re: Turbos and BlowThru Carbs

Blow through carbs are not a simple or easy deal to build. At $1350 mine is a steal for what goes into it. FWIW I don't make any more money on a blow thru E85 deal than I do a $600-$700 naturally aspirated deal, if that tells you anything.

There are some very unique challenges to building a blow through carb that works correctly. At low boost levels you can get away with minor mods and basic carb builds, but more serious programs need a lot of attention in areas that NA and nitrous builds don't. Fuel management in the bowls, fuel flow volume through the metering passages, correct emulsion for a flat fuel curve, and the proper booster spec to make it all work together.

Don't get me wrong, I am not discouraging the do-it-yourselfer from building a blow through carb, just be aware that you are in for quite a project if your program is at all serious. I consider a wide-band or EGT a requirement for tuning (besides the old reliable plug reading) to get a flat fuel curve. Most guys will just dump a lot of fuel at it to make it "safe" and give up a lot of power in the process.

I hope that helps.