Twin Turbo 383 questions

-
CUUDAK

CUUDAK

Well-Known Member
Joined
Apr 13, 2008
Messages
2,002
Reaction score
94
Location
Hempstead, Tx
I am new to the Turbo thingy and have been searching the internet to determine what turbo's to choose. Most of the drag cars down here are going turbo and WoW, they are getting seriously fast! Obviously Garrett is the instant choice but I was struck by a damn lay-off!
I have read many comments on the Masterpower brand and looks like this may work for starters. Only one concern is that I cannot find info stating that they are "ballbearing" type. I think that with these things spinning 10's of thousands of rpm's that they really need to be bearing type.
I found some so-called 70mm's on ebay for $188 but I am aware of "you get what you pay for" thingy
I have decided to use a Blower camshaft and work from there. I am converting my 850 Holley DP to a Blow-thru per an article from "turboforums". This will get me going in the direction I am aiming for.
I have a few questions about the exhaust turbine size. Seems from what I have read that the .68 is gonna work but something was said about back pressure. I would think that the wastegate would correct this as well as the mid-to-high rmp shutter. Is the smaller size gonna spool up quicker? Or should I go with the .98?

Come on, Bang heads with me!
 
Turbos have been spinning thousands of RPMs with bushings in industrial applications since before most of us were even thought of. Unless this is a serious all out race app the ball bearing unit is a luxury that may actually have potential for failure before bushings. There is a guy back east running a boosted 383 in an orange Challenger that pulls in the 9s! I think it may be supercharged instead of turbos but still some good info on what to do to the block to take it. Small will spool faster which is nice on a street car. There are several charts available to help match turbine size with displacement. One article in Hot Rod archives should help you a bunch.

http://www.hotrod.com/techarticles/engine/hrdp_1008_whats_new_in_turbos/new_technology_in_turbines_rear_mounting.html

"One Turbo or Two?
Single big performance turbos might be required to conform to specific sanctioning body rules limiting the number of turbos, or in narrow-bodied Bonneville Streamliners with clearance problems (which don't need to spool up quickly anyway). Fortunately, they're available: Turbonetics' large 115mm-inlet compressor can support 2,800 to 3,000 hp on gasoline; a 122mm prototype in the works can support more than 3,000 hp. Precision's HP118 turbo is rated to 2,800 hp on its own, while Pro Mod 108s can support more than 4,000 hp when used in a twin configuration. For the majority of nonconstrained applications, the crossover point from single to twins is still in the 700-to-900hp range, however."
 
Mguner is correct, ball bearings are a luxury, they allow the turbo to spool up faster. The cool thing is you have a big block to spool those babies up. The question you have to ask yourself is this, what horsepower am I looking for. Then you have to decide are you going to use race gas or Pump. Intercooled or not. How much boost are you willing to give it. Believe it or not all these things need to align to properly size your turbo. You are right about the exhaust/turbine housing being to small will choke the motor and it will not make any top end power. Seeing how you have a 383 inch motor with a redline of 5500, I would say go with the .98 housings. It may spool up a little slower but this may save you grief in the traction department. Obviously you are considering twin turbo, there is so much to consider, so lets start by answering the questions above and I will try to get you an answer.
 
turbodart68 said:
Mguner is correct, ball bearings are a luxury, they allow the turbo to spool up faster. The cool thing is you have a big block to spool those babies up. The question you have to ask yourself is this, what horsepower am I looking for. Then you have to decide are you going to use race gas or Pump. Intercooled or not. How much boost are you willing to give it. Believe it or not all these things need to align to properly size your turbo. You are right about the exhaust/turbine housing being to small will choke the motor and it will not make any top end power. Seeing how you have a 383 inch motor with a redline of 5500, I would say go with the .98 housings. It may spool up a little slower but this may save you grief in the traction department. Obviously you are considering twin turbo, there is so much to consider, so lets start by answering the questions above and I will try to get you an answer.
Click to expand...

Here is where I would like to be,
Looking at around 800 streetable horsepower, I will be using premium fuel. I already pay for premium due to the 12-1 440 that is in it now. Intercooled will be more effective and less heat forced into the engine so definitely intercooled. I also will be running the 4 speed and 3.55's. Boost can be as high as 18-20psi. Now if this can be achieved with one turbo of course that would be more cost effective on my side.
I like to race occasionally when my wifes out running her Big tire Mustang. I traded my 8.90 66 Falcon for this Cuda so I no longer have a racecar. We like to take as much weekend money as possible at the local tracks on a Saturday evening. Helps pay for the Hobby if you know what I mean.

Thanks for the info.!
 
Prine said:
Here is the answer. Go Single...Do it Once, Do it Right..Garrett GT4202R
http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT42/GT4202R_774595_8.html

Get the 1.15 AR Exhaust housing and this turbo will be more than enough.

Twins cost x2 anyways, so look at it this way...you'll have a Proper Single setup inplace of a cheesed together twin setup for the same price.

:read2:
Click to expand...

I like your choice, however do you think it may be over kill for 800 hp goal? The only question I have is will he have any trouble getting it spooled up being a four gear car? I know he can use a two step to build boost on the line but what about shifts? Now that I think about it that may help in the traction department.
 
turbodart68 said:
I like your choice, however do you think it may be over kill for 800 hp goal? The only question I have is will he have any trouble getting it spooled up being a four gear car? I know he can use a two step to build boost on the line but what about shifts? Now that I think about it that may help in the traction department.
Click to expand...


Quite pricey for just being laid-off($2499). What about the GT45's on ebay. $300 each. With the .96 exh.. I rarely let off the throttle while shifting. Foot to the floor and tapping the clutch.

I am fabbing the headers and tubing so that is not a problem. also have a Greddy intercooler as well.

O, using moderately ported 906's, target comp ratio around 8.5-9 to 1.
 
I never said a GT45 wasnt capable, heck the Mp T70 is capable. I said the GT4202R is the endall for the street turbo V8's...and doing it is worth doing right.

I myself (eventually on my Duster) will probably use a GT45 variant as well :snakeman:8):read2::clock::cheers:
 
CUUDAK said:
Quite pricey for just being laid-off($2499). What about the GT45's on ebay. $300 each. With the .96 exh.. I rarely let off the throttle while shifting. Foot to the floor and tapping the clutch.

I am fabbing the headers and tubing so that is not a problem. also have a Greddy intercooler as well.

O, using moderately ported 906's, target comp ratio around 8.5-9 to 1.
Click to expand...

I would be careful with turbos off ebay. If they are used have them disaasembled and inspected, not bad on price. I would consider even using a pair of T04s since everyone seems to throw them away these days. I built a car years ago with 2 T04s on it with a water to air intercooler and 377 inches of small block chevy. Its gone high 8s at over 160 at 16 pounds of boost and an 8 inch tire. You will be surprised at how fast you can go with a small turbo. Your combo looks good, I would use a bigger exhaust housing like the one your talking about .96 A/R.
 
turbodart68 said:
I would be careful with turbos off ebay. If they are used have them disaasembled and inspected, not bad on price. I would consider even using a pair of T04s since everyone seems to throw them away these days. I built a car years ago with 2 T04s on it with a water to air intercooler and 377 inches of small block chevy. Its gone high 8s at over 160 at 16 pounds of boost and an 8 inch tire. You will be surprised at how fast you can go with a small turbo. Your combo looks good, I would use a bigger exhaust housing like the one your talking about .96 A/R.
Click to expand...


So this A/R size of .96 wouldn't be too much using 2 of these turbo's right?!
 
turbodart68 said:
.96 ar
Click to expand...

WOW seems big for a small motor.......maybe I can run 2 of the GT45's on my 360 build. Only thing is the exhaust housing on that turbo is 1.05 ar.

Mikes TT Big Block Nova spools them up easily! I am slated to do a single but now you got me thinking which is really a bad thing...haaaaa


[ame="http://www.youtube.com/watch?v=_6VdAHJFh3Y"]http://www.youtube.com/watch?v=_6VdAHJFh3Y[/ame]

[ame="http://www.youtube.com/watch?v=npwI7gJRTNw"]YouTube - 47 Street car Shoot-Out Edm[/ame]
 
IIRC the term GT45 is a family of turbos. Kinda like the generic term small block Mopar. They have a few different versions of that turbo. I know they are a small frame turbo using a T04 exhaust flange which is the limiting factor on those. I heard the ones sold on ebay are 61mm inlet even though it say 4 inch which would be 96mm roughly. Not possible. Turbos can be as complicated as specing out parts for your small block. Compressor housing, compressor wheel, exhaust housing, and turbine wheel all contribute to a proper working turbo. If I were you I would be thinking twins unless you go with a large frame turbo. I know what kinda power your used to and if you want to knock it outta the park then I recommend doing some homework on which turbo you want and where you get it. I think you mentioned you already had the turbo from ebay, if thats true then twins are what your going to need to make good power. Boost isnt the only thing to consider when figuring out how much power it will make. Whew, sorry for that.
 
Well with 1 single turbo using a PT8847 there are guys running in the mid 8's with little 347 cu in Ford's.................Damn that is FAST! So one of these as a single would work well no?? Should be able to do the same with a little 360 it seems! I may change gears on the turbo choice. I was starring at the 67 tonight and twins would be a chore to get in there for sure! I think you are right with the GT45 it would probably hit the 700hp range with a 410 CU IN engine, checking it out more it would run out of steam up top.
 
From a member of the turbo forums. 114 mm Gtrim, 1.5 ar. 9.3:1 pump gas with a small windshield washer injector. When it was dynoed with an intercooler it made 1464 rwhp at 13.5#'s of boost with an intercooler....
[ame="http://www.youtube.com/watch?v=oRBC7cZ-JiU&feature=related"]YouTube - Matts turbo dart[/ame]
 
Mad Dart said:
Well with 1 single turbo using a PT8847 there are guys running in the mid 8's with little 347 cu in Ford's.................Damn that is FAST! So one of these as a single would work well no?? Should be able to do the same with a little 360 it seems! I may change gears on the turbo choice. I was starring at the 67 tonight and twins would be a chore to get in there for sure! I think you are right with the GT45 it would probably hit the 700hp range with a 410 CU IN engine, checking it out more it would run out of steam up top.
Click to expand...
Don't be afraid Louis, I stumbled accross a picture of twins on a big block.....course it is on my lap top out in the garage, I will run out to the garage to get it...
 
That is some serious header fabrication and a stuffed engine bay for sure! The turbo exhaust out would be a *****. See how he ran them different on each side. No Intercooler either which would make it crazy busy with a air to water system..........meth would be easy.
 
inkjunkie said:
From a member of the turbo forums. 114 mm Gtrim, 1.5 ar. 9.3:1 pump gas with a small windshield washer injector. When it was dynoed with an intercooler it made 1464 rwhp at 13.5#'s of boost with an intercooler....
Click to expand...

That Dart is cartoon quick.............I was laughing hard watching that one........Dang!
 
I think with a little bit of inner fender well cutting the headers/exhaust would not be that bad......
 
You must log in or register to reply here.
-

Back
Top