Blow Thru Carb

I know your pain Adam.:biggrin:

Getting the turbos to balance will be the biggest problem. Using two of them can be somewhat problematic to say the least. Do a search in the general section as well as the turbo section.

That's been on my mind as well. I have all the turbo books people suggest and IIRC, there is a way to join the turbos together to equalize or balance the pressure with a crossover tube. I'll have to crack the books open again to double check.
BTW, I'm pretty sure the twin turbo 4.1 had that done as well.
 
You could always do it so that one blows into the intercooler and then into the second one to increase pressure, then route it into another intercooler. That would double the pressure easily. Look up Rick Dobertin and see if you can find one of his creations. The two that I know of has twins blowing into a supercharger and worked fairly well.
 
You could always do it so that one blows into the intercooler and then into the second one to increase pressure, then route it into another intercooler. That would double the pressure easily. Look up Rick Dobertin and see if you can find one of his creations. The two that I know of has twins blowing into a supercharger and worked fairly well.

:eek: That sounds wicked, but maybe more over the top than I want.

As for those thinking I should go single, I might do that, but only if I use a 4.1 block.
I think twins would be better for reasons previously stated, even for the 4.1. ;)
 
Twins or single? I don't really see one outperforming the other both will perform well as long at they are optimizerd for the right AFR. Single system will always be cheaper and easier to tune.

The stock'86-'86gn/T-type cam will not reach 6500 it's dead at 5000 or 4500 if you have stock valve springs, you will have to go with a roller cam or a special flat tappet.

Carb selections are pretty much any holley 4150, demon, the new summit carb.
The Carb Shop, QFT, CSU, C&S can all build you a blowthru carb for a price, VS you buying a demon or building your own carb, spending lots of time testing, trial and error, tuning and using math to get the carb tuned well with a RELIABLE AFR.

Carb hat or bonet: This peice is a big deal don't get junk and never use the turbonetics hat it's less than trash.

MUST get a WIDE BAND o2 controller, VERY IMPORTANT!!
You need something to control the ingition curve.
 
WarWagon said:
Twins or single? I don't really see one outperforming the other both will perform well as long at they are optimizerd for the right AFR. Single system will always be cheaper and easier to tune.

My thinking is thus: Lower boost for same power, that means less detonation risk. It will be run on pump gas in AZ where it's not unusual to see 115+ degrees during the summer. Yes it requires custom fabrication of exhaust manifolds, but I have a MIG welder itching to be used.

WarWagon said:
The stock'86-'86gn/T-type cam will not reach 6500 it's dead at 5000 or 4500 if you have stock valve springs, you will have to go with a roller cam or a special flat tappet.

Hmmmm. Looks like I'll have to go with something a little hotter then. Any suggestions? I'll upgrade valve springs as needed.

WarWagon said:
Carb selections are pretty much any holley 4150, demon, the new summit carb.
The Carb Shop, QFT, CSU, C&S can all build you a blowthru carb for a price, VS you buying a demon or building your own carb, spending lots of time testing, trial and error, tuning and using math to get the carb tuned well with a RELIABLE AFR.

I was actually thinking of the carb shop due to their reputation. Either that or a Holley 4150 since it has a proven track record for blow-thru setups. I'll have to check out those other companies. Things have changed since I last researched carbs and blow thru.

WarWagon said:
Carb hat or bonet: This peice is a big deal don't get junk and never use the turbonetics hat it's less than trash.

I knew the right one was important. Didn't know the Turbonetics one was crap. Guess they should stick just to turbos.

WarWagon said:
MUST get a WIDE BAND o2 controller, VERY IMPORTANT!!
You need something to control the ingition curve.

That was on the list as well as tuning by a local shop. Also a MSD BTM is on my mental list of things I need.
Thanks for the info. It's extremely helpful and appreciated.
 
Like the new avitar Adam. lol Glad to have you in once again for input. A single will respond better unless you go with two small turbos. Getting them to flow at the same rate is a pain but it can be done. It will be much easier to run a single and it should give you the best overall effect unless you're just going for "wow" factor.
 
Like the new avitar Adam. lol Glad to have you in once again for input. A single will respond better unless you go with two small turbos. Getting them to flow at the same rate is a pain but it can be done. It will be much easier to run a single and it should give you the best overall effect unless you're just going for "wow" factor.


Haha. The only wow factor I am interested in is when I hit the gas. I'm not a bling-bling type of guy. :cool:

I have one T3 turbo and will obtain a second one, so yes I plan to go the small turbo route.
I know a single would be easier and cheaper, but I like to have as much safety built into an engine as possible. Less boost needed, less risk of detonation on 91 octane squirrel pee or even 89. Intercooling is mandatory and alky probably will be too.

The only thing I think would keep me from going twin, is if the consensus is that to run 12.0's in a 69 Buick Skylark boost will not need to be too high.
Remember, this car WILL have A/C and be driven during the summer on 91 octane where triple digit temps outside are the norm. Oh and BTW, I'm trying to keep turbo lag down too. I don't ask for much, I know.

Last but not least, here is a link about joining exhaust manifolds to equalize exhaust pressure to the turbos which balances flow. Look under Heat Risers & Carburetor Heaters.
I have the book it's out of. :biggrin:

Turbochargers - Google Books
 
The big thing is getting the turbos sized for twin use. You should probibly use two off of a 4 cylinder to get the best response since it will have the smaller exducer on it. Somewhere around a 1.8 to a 2.0 Liter engine shuld be just right for you. If you use the one off the V6 Buick it wll be very lag prone due to the size of the exducer wheel. A smaller wheel will give much better response in the long run. 231 divided by 2 is about 115.5 CID so you need to find a turbo intended for an engine some place in the 140 or smaller CID to spool better.
 
The big thing is getting the turbos sized for twin use. You should probibly use two off of a 4 cylinder to get the best response since it will have the smaller exducer on it. Somewhere around a 1.8 to a 2.0 Liter engine shuld be just right for you. If you use the one off the V6 Buick it wll be very lag prone due to the size of the exducer wheel. A smaller wheel will give much better response in the long run. 231 divided by 2 is about 115.5 CID so you need to find a turbo intended for an engine some place in the 140 or smaller CID to spool better.

Excellent point. The T3 I have is off a 4 cylinder, but I had planned to consult with a turbo company to ensure it was sized properly and send it off for changes as needed.

There is one thing that may keep me from going TT. Space. That darned steering link may only provide room for headers. As it is it even makes headers a pain. Yes a TT been done on a 350, but only with serious effort.
I'll have to mock something up when I have an engine block.
 
You mean something like these? These were made for a TTA so if it'll fit in there then it'll fit in a G body.:biggrin:
 

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For some reason I can't see the pic. It's just an X in a box. I may need to clean out my cookies but check and see if you can see it.
 
Do a left click on the pic and copy it to your files. Then upload it here. If you're not a member you can't see see it.
 
Do a left click on the pic and copy it to your files. Then upload it here. If you're not a member you can't see see it.

Let me try that way.
My concern is that even with the 6 the lack of space will be the same problem. He chose that square log manifold because the header type for turbos wouldn't fit.
 

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Those are cast iron manifolds. Good luck finding a set for a Buick V6. I remember them on evilbay some time ago.
 
Those look like part of a twin turbo kit from Burton Machine.
I remember a guy in Pittsburgh building a blowthru buick 350 and he bought one of their kits, everything looks just like the stuff in these pics. I put spaces in the link
http:// burtonmachine. itgo. com/
 
If you start with a single, then everything is easy - just use readily available exhaust stuff off a 86/87 TR. Then move to twins later if you need to. Look at some of the really fast cars out there on a single turbo. You'll have more than enough to keep yourself busy with tuning the carb, etc.

How will this car have AC and two turbos? Are you going to have a distributor, power streering and an altertator too? That's a lot of junk on the front of the motor.

89/91 Pump gas? really?
 
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