Turbos and BlowThru Carbs

[TC]

So with all this talk about Turbo's, I'm thinking of changing my idea of a Junkyard nitrous motor(which I've already done) to a Junkyard motor using one of these turbo kits off Ebay. But instead of having to deal with the hassle of EFI and the headaches of tuning it I figure the fastest and best way would be going with a BlowThru Carb.

Now normally on a naturally aspirated 350 I would run a 750 cfm carb, but doing a turbo motor would you want to increase the Carb size?? Like go up to an 850??

Also I saw BlowThru carbs on EBay for 5-600 bucks, opinions??

[A/Fuel]

The bigger carb will flow more right? LOL!!!!!
Just do it.....I dare ya!

[milner351]

I've been thinking along the same lines (the ranger headers where cheap enough)

I would try to find someone who's built a blow through on the same size engine and see what they are running.

I don't know how boost effects flow rates in relation to engine size/pumping loss/volumetric efficiency
- the cfm ratings are done at a constant pressure across the venturi's - so obviously boost changes everything.

[STINEY]

2 words - - Modulator Rings.

Nobody seems to know what they are or what they do for carbs under boost.

[joe_rocket45]

I think the idea is to go with a slightly smaller carb to boost signal to the boosters plus the restriction helps cool the charge slightly (but to me that's only b/c the restriction makes heat pre carb, right?)... anyways do not try to over carb a blow through setup

[88 Dippy]

i have been having the same idea with my LeBaron. the stock fuel system is none tunalbe so you have to buy a stand alone or MegaSquirt.

but i am cheap i just want to put a turbo on it and a carb lol :D the stock ECU would still controle timing if i left th injectors pluged into the connectors it would be so redneck though

[BangShiftChad]

Several guys on here are fans of blow through carbs. I have seen blow through setups run perfect almost half as often as I've seen them run like crap. LOL

I think the safer solution is to use a box instead. Like a Vortech box. The carb doesn't know it's under boost that way, and it's always happy. We've run the Camaro that way, and still do, and it works great.

But, I've known guys that ran less than 10 pounds and just did a hat on a regular carb.No tricks.

[dieselgeek]

I vote for the box! Freiburger had that blower motor running like a champ with the carb box... he said it was totalyl easy to do too. I trust him.

and, I think it's pretty clear that a blow-thru carb with anything more than low boost is far more rocket science than any EFI setup - and a heluva lot less forgiving, there are *experts* who have a single mishap (oops, ran a few psi too much boost) and burning holes in expensive parts.

But, anything that gets TC off the keyboard and into a running car, I'll support no matter what it runs! haha

[TC]

So what I'm hearing is run the same size carb that you would run naturally aspirated, but use a carb box instead or a blowthru carb.

[seanm]

No need to go to a bigger carb for a blow- through. The same or a little smaller is fine. 750's have supported 1000hp+.

Most use a bonnet, and that is what most guys that use blow-through know about. The box isn't as popular. Have never used one. But it might work great.

The carb will need to be modified and tuned, so you can't get away from that. There is a lot to learn and more than one way to modify a carb to work with boost.

This is a basic guide to building a blow through carb: http://www.hangar18fabrication.com/blowthru.html

It covers the basics only. That may be all you want, depends on how "perfect" you want to be.

and, I think it's pretty clear that a blow-thru carb with anything more than low boost is far more rocket science than any EFI setup - and a heluva lot less forgiving, there are *experts* who have a single mishap (oops, ran a few psi too much boost) and burning holes in expensive parts.

Oh blessed goddess of speed, lets not turn this into another carbs vs EFI thread.

In what way is a carb for high (please define) boost "rocket science"? Have you built carbs for blow-through? Thats an honest question? Would like to know your experiences good and bad with blow-through carbs.
Have seen EFI cars tuned by "experts" with burnt parts too. So EFI and carbs both can suck ;)