# Turbo carb?



## Montrocco (Nov 9, 2009)

one of the few production cars to ever be turbo/ carb were the corvair spyder and the trans-am turbo. Both those were disasters at best and never really had the right feel
The problem is that the carbs you want to use have no way of telling when there is boost. Plus, since you have 4, i guess youl want to blow-thru so you would have to box them and put a device to raise fuel pressure. Then you need to figure out a way of enriching the mixture under boost. then you also have to to pressure-retard ignition. It would be a lot easier to go with a volvo 240 turbo cis setup with the dizzy and wur. You could use a modified distributor from mk1 with the dual diaphragm canister.
If you really want to go carbs, sell the ones you have and buy a very common weber downflow 32/36 dgv. do it draw thru. (make sure you have a turbo that has mechanical seals that can seal vacuum. If not, add a butterfly downstream of the turbo and have it close a little before the carb so the compressor never sees vacuum.) Set up the secondaries to operate on boost and jet them RICH! This way, as soon as boost start building up, the secondaries will open and you will feel a real rush in power. Don't forget to install a small pneumatic valve linked to the primaries to vent the secondary diaphragm to atmosphere, Otherwise, the car will keep going full bore when you take your foot of the throttle, not cool,,, Don't forget the pressure-retard dizzy. 
That's probably the simplest, cheapest and most reliable/ flexible turbo/ carb setup you can have. Don't forget that when you turbo the car, it usually takes LESS carb than if you would tune it the regular way. therefore, one 32/36 dgv is more than enough for the 2l ABA. plus, parts and jets are cheap and plenty as it is extensively used in formula ford and as replacement for carter, rochester, etc..
Hope this helps, cheers


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## dubdaze68 (Oct 29, 2001)

*Re: Turbo carb? (Montrocco)*

Car that used that setup was the Maserati Biturbo.
























Another setup is to use the MG Metro Turbo carb, it's the SU type.








HIF44


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## Montrocco (Nov 9, 2009)

*Re: Turbo carb? (dubdaze68)*

Those are all pretty hot setups for back in the day. I would go draw-thru for ease of installation. Otherwise, you have to box the carb like that Maserati diagram. SU blow thru works well. There was also a mini metro kit that used Weber sidedraft blow thru that worked really good. Same for fiat X19
The only real issue with draw-thru is fuel lag. and also fuel puddling if you use an intercooler. The turbo seal also 
Awesome pics where did you find those antiques?


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## dubdaze68 (Oct 29, 2001)

*Re: Turbo carb? (Montrocco)*

Google is your friend...I just know what I'm looking for. You know, I've never seen SU's on a Rabbit. Talk about a dead simple carb....If you have all the needles to tune with.


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## Montrocco (Nov 9, 2009)

*Re: Turbo carb? (dubdaze68)*

Yeah for sure, if you have all the needle and base jets it's great. they even have some models needles with multiple tapers to give higher enrichment at different piston heights. Works half decent for turbo. It's just that you're always really rich when the boost starts and lean near the top.. So it bogs a bit off idle to lets say 2k and than it goes like the scalded cat to 6k, but you can't hold it there too long as it's not really rich enough.


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