I know there have been plenty of turbo'd carb vehicles in the past. And I'm getting serious (AKA, now have income) about adding turbos to my carb'd Bronco.

SO, I've gone out and bought a few books on turbos and supercharger theory.

The best one that I've gotten SO FAR is "Maximum Boost." These books teach a little more than the fluid dynamics classes I took in ol' college.

In the book, it mentiones that a turbo and a carb will be at odds with eachother due to the designes. That the turbo will either make the engine run WAY too fat under no boost, or will force the fuel back into the tank under boost.

But, then he goes on to mention that as long as you set up a blow-through system and put a fuel regulator that varies pressure in relation to boost that you'll be fine.

What gives?

I've got one engine that I'm going to put a turbo on and one that I'm putting a Mega-Squirt on. Should I stop expirimenting and just put the turbo on the fuel injection engine??


-Dave....Cheap and Easy.

 

The fuel regulator you mention is known as an FMU (fuel management unit) and restricts the amount of fuel that is allowed to return to the tank (on a return type of fuel system), thus increasing the fuel pressure.
The only obstacle I see with a carb/turbo setup is that the motor can be under full boost at only part throttle, and the carb might not give the motor enough fuel to maintain healthy...otherwise known as a tip-in-lean condition. Now on an EFI motor w/MAF, the air meter measure the amount of air going into the engine at any throttle position and match the amount of fuel that is needed.

 

Remember, that there are two ways to route the turbo to the carb: 1 - "Blow Through", where the carb is downstream of the turbo, and the turbo pressurizes the carb: the biggest problem is increasing the fuel pressure as the boost rises, othewise the fuel won't exit the carb. 2 - "Suck Through", where the carb is upstream of the turbo, and the carb sees no boost. If you have the room to route the plumbing, then "Suck Through" is the simplest, most effective way to go.

 

never heard or seen a suck through but i know that companies make fuel pumps that have a vacuum port on them that senses boost and ups the psi when the boost goes up. do you have any info on suckthrough setups. i may do that to the stang. i have the turbo.

 

I not sure, but weren't the early(before F.I.) 2.3 Mustangs suck-through? The big problem with the suck through installations is clearance. If the intake and exhaust are on the same side, things get kind of tight.

 

I've pretty much ruled out the draw-through set up.

I guess I was looking for confirmation that using the carb would be OK.

BUT, I suppose I could go ahead and put my little MegaSquirt system on there and check it out.

Heck..I'll do it both ways.

Now if I can only find a shop that'll weld up the pipe I need without going crazy about "It's not smog legal!!"

Maybe I'll tell 'em it's a trailer queen.

 

Go to Paxton website, they make an incredible & simple blower/carb combo. If you remember they were in cahots with Carrol Shelby & built the carb/blower set up for the 65-66 Gt-350's, its still available but much improved & believe me it really wakes up a 302/5.0.
Their tech staff will walk you through the whole process, know your car weight, rear ratio, compression, transmission as they will ask you all this stuff.

 

When using a blow throu setup make sure that you spend the money on a blow thru carb. We tried once to do our own changing the floats and expoying some holes shut. The combo worked but never right. Soon as we paid the big bucks for a nice blow thru the car ran very good. Yes you have to run a fuel pressure regulator with a boost port. Usually it raist fuel pressure a 1:1 ratio

Draw thru setups work fine if you can find a good base hat. I have only seen a few of these kits an they were in the 5-7PSI scale.

I have seen a few on ebay.

 

yahoo groups, "blowthrough" is the name of a site my buddy told me about, his truck is on there, he's got a SBC 350 with a t-3 soon to be a T-4

let me know what kidna info you may need

 

One source for specific built blow thru carbs is http://www.performancecarburetors.com/

 

I did a draw thru setup on my 300 straight six. The only thing which needs to be changed on the carb, is the vacuum pickup to the needle valves need to be down stream of the turbo, so when drawing air thru the carb, the needle valves don't get pulled shut.
I also used a Aerotech fuel pressure regulator, which has a vacuum port. When under boost, my fuel pressure goes from 3 psi, to 12 psi, works great. Don't buy a cheap regulator, and try to modify it, I tried this first, and it didn't work.

 

Go to www.turbomustangs.com there is a ton of turbo info there in forums, one is specific to carb and turbo combo's. Good informative reading.

 

Yea Rob thanks for letting everyone know. I am a member there, Thats how I have learned what I know.

Also just in the future I don' think that this site likes other web sites with fourms to be posted with an URL.

Your right though, Turbo mustangs it the place for blown fords period.