blow-through turbo setup. which carb is better to use?

[antzbongo]

Gday guys, im doing a blow-through setup. Running an F8 mazda block, 626 turbo capella pistons, just changed rings, chucked the block back together, in the middle of making up turbo exhaust manifold at the moment. Just wondering if anyone's used blow-through setups before. Ive been told that weber carbs are good to use, as long as theyre pressurized, and run a boost controlled fuel pressure reg. with an electric fuel pump. am i missing something here, or is that pretty much it? or are there better options as far as carburettors go for boost applications?

any help would be appreciated. thanks

p.s. heres a link to the build: http://www.rangimods.co.nz/rangiforu...opic.php?t=285

[UncleBob]

not very helpful, but go for the cool factor. Get a set of motorcycle carbs.



Otherwise, sounds like you have your bases mostly covered.

[antzbongo]

sweet thanks mate. do certain bike carbs run good under boost? ive heard that apparently dellortos dont need any adjustments, and with just a fuel pressure regulator they run ok. are those dellortos there? im quite new to the whole carburration side of things, so yeah.

[UncleBob]

I have little to offer on "car" carbs, since all of my blow thru turbo carb setups have been on bikes.

I would assume carbs such as webers would work well, because of their simplicity. Much like motorcycle carbs, they don't have a lot of complex valving and doodads that are designed specifically for naturally asperated issues, which can be thrown way out of whack on blow thru applications.

I've never even heard of "dorito" carbs....do they give you the munchies? (just kidding)

As for what bike carbs work well, CV carbs or flat slides work great. I usually use Keihen's, but thats mainly because of the bike models I have turbo'd used them to begin with. If you want some suggestions on bike carbs to look for, if you really are interested....whats the parameters of the engine? Whats you HP goal, whats the valve size you'll be using? How much money are you willing to spend on carbs?

The high end carbs, brand new, can get over $1000 (such as 41mm FCR's ....awesome carbs if you got the cash). But you can get much much cheaper used OE carbs off ebay for $100

[antzbongo]

thanks for your reply there mate. well ok here is some more info for you jsut to give you an idea:

this is a motor out of a Mazda Bongo van (not friendie, but an e-series bongo). its a small project for my website - rangimods.co.nz which is a website made just for shits and giggles, and demonstrates a really rough and unprofessional approach to automotive modifications.

the parts, such as the block, gearbox, even the turbo were donated by our forum members, and we are trying to set this van up to race it around the track.

Block: standard 1.8L mazda F8
Pistons: Mazda 626 Capella pistons, new rings
Head: standard 8 valve head, standard camshaft, etc
Turbo: not exactly sure, but it would be the size of a vf8 turbo

so yeah, just need a semidecent carb setup, to make sure it doenst lean out, and gets enough petrol. If we can get 200Hp out of this block ill be extremely happy. But i mean anything over standard 85Hp is an improvement.

So yeah the cheaper the better. I have an intake manifold for a single carb, but i can always chop it up if necessary. So any suggestions on what carb size, etc, maybe off which bike, etc.

Thanks for your help.

Ants

[curtis73]

Most carbs will take to boost pretty well with some modifications. Qjets are probably the least easy to modify this way but I doubt you'll need a Qjet for such a small displacement.

Cruise on over to our forced induction forums listed under "cars in general". They might have a bit better finger on the pulse of which carb works best.

[UncleBob]

again, not sure how serious you are, but a great carb bank off bikes would be a CVK36, 36 mm CV carbs made by keihen. Best applications to get it from are 99-00 kawasaki ZRX1100, 01-05 kawasaki ZRX1200, and 95-96 GPz1100

They are all the same carb, side draft. What I work with a lot. Plenty of carb for your engine, but CV, so they will keep decent low RPM performance. The details of making them work on a turbo application is very simple. Just need a pitot tube, which is a fancy way of boosting the bowl vents, but nothing difficult. Otherwise, just your standard jetting of any carb

same carbs on the picture I posted, which is a toyota 22R motor that I'm building for a 69 corona (not sure if you had those in NZ)

[Moppie]

A Turbo Bongo!
Choice bro!!!!!!



Looking for something different instead of usual rotary swap?

Originally Posted by antzbongo

Ive been told that weber carbs are good to use, as long as theyre pressurized, and run a boost controlled fuel pressure reg. with an electric fuel pump.

This set up worked for Lotus for 20 odd years in the Turbo versions of the Esprit.

Makes one hell of an awesome noise too

[antzbongo]

Thanx uncleBob, ill defiantely research those options, will see what i can find for sale.

Originally Posted by Moppie

A Turbo Bongo!
Choice bro!!!!!!

Looking for something different instead of usual rotary swap?

i already got a bongo with a v8 in it:
http://www.youtube.com/watch?v=tJPwmAtFyBw

so this time gotta do something different again.

[Moppie]

Originally Posted by antzbongo

i already got a bongo with a v8 in it:
http://www.youtube.com/watch?v=tJPwmAtFyBw

so this time gotta do something different again.

Ah, yes. I have seen that before, I think it was that Dodgy Performance Car TV or similar.
Need to ditch those SU's though, and put some real carbs on it

If you want something really, radical theres a Turbo Honda V6 on trademe at the moment.