4 barrel turbo?

[The Revelation]

ok so im building my own blow through housing for a arizona z car 4 barrel carb (holley) (basically cause i was tired of balecing) i was wondering if anyone thinks that would be a good idea, or if anyone else is running that setup. it will not be for a while because im undergoing a frame off restoration but the body should be done soon so then i get to the fun stuff. (the engine and suspension )

[JMortensen]

Do a search. There was a VERY successful 4bbl draw through turbo setup (like 500+ hp). I'd suggest you go that way and forget the blow through. Search for "Bob H" and "Bob Hanvey". He bought a car with that setup that had huge IMSA flares. I think he was going to swap out the motor for an RB though.

[Clifton]

My first turbo car ride was in a blow through 4bbl 240Z. It hooked me.

 

I believe trubomioester, ususally on the v8 section runs blow through.

[Cobra_Tim]

http://www.turbomustangs.com has a VERY good section on blow through 4brll applications.

[Clifton]

www.turbomustangs.com[/url'] has a VERY good section on blow through 4brll applications.

 

I was on there and amazed. 1000 rwhp blow through street car. Carbs seem popular on there.

[ww]

I prefer the blow-through vs. the draw through. There's nothing worse than having fuel pool at the bottom of your turbo housing and or intercooler and having pre-ignition light it up through the intake... FFFFOOOOMMMM!!

 

Blow throughs have their own set of problems with carbs that weren't designed to hold positive pressure especially 15, 20 and even 30 psi. But, in my opinion, the end result is a more reliable vehicle with ultimately more potential.

[AK-Z]

With the way the intake manifold is usually designed for the 4 barrel setup for these engines. There is usually a lean issue on the 1 and 6 cylindars because of the runners. With a draw through you won't have that problem because your setup would a/f mixture will be equally distributed.

 

The problem I see is if you set it woth too much fuel, some might condense and settle inside the turbo. Might go boom, under the right conditions.

 

There was a a company that makes just sealed carbs and are fairly cheap and easy to find. Most of the VW dunebuggy guys use them. I don't recall the name but I'll look around for it.

[FEnatic]

If you want to use a 4 barrel, why not look into a Holley Projection unit. A friend of mine overseas ran one in his Z with a T04 blowing through it, ran real well too. Plus you get the added benefits of fuel injection. My .02

[z-ya]

I've seen a number of blow through 4 barrel setups, one was on a twin turbo Chevy small block 240Z. I saw it at the MSA show a few years back. The way to do it is presurize the entire carb (put it in a box). This guy had built an aluminum box that had a lexan top so you could still see the carb. Kind of cool looking.

 

The Holley projection system is a POS IMO. You are better off with Megasquirt and port injection. Oh, and then you might as well run an 280Z manifold, and just forget about doing anything with that 4 barrel manifold and carb. Or, you can use a the Megasquirt ECU to control a TBI throttle body. Anyway, it's a lot of work to keep that manifold if you decide to go with fuel injection.

[AK-Z]

I may be wrong, but I see the reason in going carb from EFI in being the tuneablity. With EFI you would have to be able to adjust fuel maps (pretty hard on the stock EFI) and maybe buy bigger injectors ($$$). With carb you would just need to adjust and maybe get different jets. Most of the aftermarket carbs are sealed anyways, but for the price of going 4barrel carb, you can get a full MS kit (comparing new for new).

 

Guess its up to you. If yo go carb, I would try to do something so you would have equal length runners.

 

Well I'm still looking for the name of that company that makes those cheap sealed carbs I mentioned earlier. I'll have to post it later I guess.

[iaconsultants]

You might be thinking about the Preditor Carb which is kind of like a cross between a throttle body and a carburator. I have done a variety of turbo and supercharged cars with carburators and I can tell you that a suck through is easier than a blow through. With a blos through you will have to make sure that you do not pressurize the float bowls or you end up with a mess that could easily catch a spark. It seems that a Carter Carburator was better for blow through than a Holley and definitly not the Rochestercrap. The Preditor works well in either case but forget about fuel economy. The best setup I felt for a turbo L6 motor was a Holley 390 suck through with a primary metering block replacing the metering plate on the secondary side. This would allow you to have a power valve on the secondaries. Then comes the fun by inserting a brass tube through the carb body and behind the power valve so you can run boost to the back of the power valves to open them up and allow for more fuel at that time. If you want more information let me know and I can probably describe it in much more detail, but for the easiest setup these days it seems that you should probably go fuel injection since that appears to be the most stable. Good luck

Robert

[ww]

Agreed. FI is the way to go now. Carbs are really just for nostalgia at this point. For the price of a turbo carb setup, you can buy a fully built MS system and save yourself the pain of trying to make a carb do something it wasn't originally designed for, aside from the custom fabrication if you can't find the original after-market parts lying around somewhere.

 

At this point, if I'm unable to get the power numbers I'm looking for, I will convert to TWM ITB's with a MegaSquirt-n-Spark stand alone setup. This will at least retain the nostalgic 'look' of triple Mikuni's, but give me WAY more tuneability.

 

In 2006, there's really no reason to do a turbo carb setup. I'm even considering a dual TWM ITB setup to replace the SU's on my 240z... Wouldn't that be entertaining?! Just what I need, another freakin' project...

 

At least I'm picking up two "low rust" California '73 240Z's for free this weekend.

 

I wonder which one will loose the crappy flat-top's and get the ITB's?