Twin Turbo 383 questions

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.

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.

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.!

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:

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:

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.

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.


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.

Time to go back to the turbo forums. Looks like several are having good luck as long as the turbo is disassembled and cleaned.

gt45 y2004k
http://www.theturboforums.com/smf/index.php?topic=96046.0

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:

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 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.

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.


So this A/R size of .96 wouldn't be too much using 2 of these turbo's right?!

True, thats the size I used on my small block at 344 inch. No problems spooling em up.

True, thats the size I used on my small block at 344 inch. No problems spooling em up.

What size did you use? Did it have Twins on it?

They were Twin t-60s.

They were Twin t-60s.

What size Exhaust Housings? .68AR?

.96 ar

.96 ar

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


http://www.youtube.com/watch?v=_6VdAHJFh3Y

YouTube - 47 Street car Shoot-Out Edm

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....
YouTube - Matts turbo dart

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. 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 Bitch. 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.

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....


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......

I think with a little bit of inner fender well cutting the headers/exhaust would not be that bad......

That's true, but I really don't want to cut it. That may change though!

Hey Mad, why dont we skip the BS and order up one of these.

http://www.compturbo.com/products/index.php?folder1=Turbo_Chargers&folder2=CT54&product=CT6-106112BR

Hey Mad, why dont we skip the BS and order up one of these.

http://www.compturbo.com/products/index.php?folder1=Turbo_Chargers&folder2=CT54&product=CT6-106112BR

You are NUTS...................haaaaaaaaaaaa

Now that is a BIG AZZZZZ TURBO 112mm and 1.50 AR Exhaust housing. I bet that Turbo is 6K!

You are NUTS...................haaaaaaaaaaaa

Now that is a BIG AZZZZZ TURBO 112mm and 1.50 AR Exhaust housing. I bet that Turbo is 6K!

Yeah!

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.

I have been getting a little skeptical lately. I have an old 57 trim rajay mocking up ideas. With the 383 room is minimal so twins may be out. I really do not want to cut my car up! I have been pondering this turbo,

http://cgi.ebay.com/ebaymotors/Precision-5030-GT-Turbo-Journal-Bearing-GT47-_W0QQcmdZViewItemQQhashZitem4cf1f39d30QQitemZ33047 6789040QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccesso ries

Considering the limited space would this particular turbo(Single) be sufficient for my application???????? Pretty big AR. of .96, 1.08 or 1.39 and states 1400hp possibilities! I am looking for 800 streetable horsepower.

I love this type of thread !! 1400 hp !! well there are very simple realities that often get forgotten. Regardless the type of intake charge boost used, the motor is still an air pump.. There are a couple volumetric considerations, but as a rule, 1 atmoshphere (14lb ) = 50 % horsepower increase. So your 1400 hp dream mobile would need to make 900 hp or so without a turbo... Which is fine, but probably means he has a fortune in that motor. This thread is about making 800 out of a 383.. a good running 383 is making around 400 hp so you could get 600 hp out of 14 lbs of boost.. I run 16lb ( blower
- D1SC ) through a 474 and make 790 hp.. I could probably get another 50 hp if I changed the very mild cam profile im running, but I like idling at 700 rpm. Just a reality check. Fun thread.

I love this type of thread !! 1400 hp !! well there are very simple realities that often get forgotten. Regardless the type of intake charge boost used, the motor is still an air pump.. There are a couple volumetric considerations, but as a rule, 1 atmoshphere (14lb ) = 50 % horsepower increase. So your 1400 hp dream mobile would need to make 900 hp or so without a turbo... Which is fine, but probably means he has a fortune in that motor. This thread is about making 800 out of a 383.. a good running 383 is making around 400 hp so you could get 600 hp out of 14 lbs of boost.. I run 16lb ( blower
- D1SC ) through a 474 and make 790 hp.. I could probably get another 50 hp if I changed the very mild cam profile im running, but I like idling at 700 rpm. Just a reality check. Fun thread.

I believe this to be true in a Supercharged engine since the engine produces the power to move the blower from the crankshaft. However I believe that this is incorrect in the Turbo engine since there is "No" power being taken to move the Turbo. I personally seen a smallblock Chivy that produced a bit over 400hp alone. After the 2 turbo's were installed it produced well over 900hp @ 20lbs boost. This proven on a dyno!

O' a stock 383 produces 335 hp stock. This was said to be with all assys. and at the tailshaft of the trans.. Furds and Chivy's were rated at the flywheel. I have seen the 383/496 produce nearly 600hp.

I believe this to be true in a Supercharged engine since the engine produces the power to move the blower from the crankshaft. However I believe that this is incorrect in the Turbo engine since there is "No" power being taken to move the Turbo. I personally seen a smallblock Chivy that produced a bit over 400hp alone. After the 2 turbo's were installed it produced well over 900hp @ 20lbs boost. This proven on a dyno!

O' a stock 383 produces 335 hp stock. This was said to be with all assys. and at the tailshaft of the trans.. Furds and Chivy's were rated at the flywheel. I have seen the 383/496 produce nearly 600hp.

The blower certainly takes a couple hp..
In the end however it simply is a matter of fact that an engine is an airpump. The power its going to make is simply a factor of how much air and fuel can get stuffed inside. That really doesnt change depending on what method of forced induction is used. ( blower, turbo, N02 )

Turbos do steel hp as well.. There is no free lunch and the huge restriction in exhuast flow will cost something. I dont know enough to tell you what those numbers look like or how they compare to a blower.. Anyone else know ?

The blower certainly takes a couple hp..
In the end however it simply is a matter of fact that an engine is an airpump. The power its going to make is simply a factor of how much air and fuel can get stuffed inside. That really doesnt change depending on what method of forced induction is used. ( blower, turbo, N02 )

Turbos do steel hp as well.. There is no free lunch and the huge restriction in exhuast flow will cost something. I dont know enough to tell you what those numbers look like or how they compare to a blower.. Anyone else know ?

Turbos restrict exhaust flow and tht is why the A/R sizing is important. Even if the turbo is a restriction the boost will be lower because of it, so with a boost correction a turbo robs very little power. Superchargers on boost rob a lot of power! No way around it and that is why it is typical to see a 100% increase in power at 15 pounds of boost. I have personally seen over 100% increase on my own car at 13 pounds.

The blower certainly takes a couple hp..
In the end however it simply is a matter of fact that an engine is an airpump. The power its going to make is simply a factor of how much air and fuel can get stuffed inside. That really doesnt change depending on what method of forced induction is used. ( blower, turbo, N02 )

Turbos do steel hp as well.. There is no free lunch and the huge restriction in exhuast flow will cost something. I dont know enough to tell you what those numbers look like or how they compare to a blower.. Anyone else know ?
I know this is an extreme example, but it is an interesting read none the less.....http://www.moparengineswest.com/top_fuel_perspective.htm in particular the third line

The blower certainly takes a couple hp..
In the end however it simply is a matter of fact that an engine is an airpump. The power its going to make is simply a factor of how much air and fuel can get stuffed inside. That really doesnt change depending on what method of forced induction is used. ( blower, turbo, N02 )

Turbos do steel hp as well.. There is no free lunch and the huge restriction in exhuast flow will cost something. I dont know enough to tell you what those numbers look like or how they compare to a blower.. Anyone else know ?

I just posted a read about cam choices. Take a look at it. The cam choice is critical in the process of creating the right lift-duration-overlap-timing to produce the Hp numbers. Poor choice in cam can ruin a decent setup!

I just posted a read about cam choices. Take a look at it. The cam choice is critical in the process of creating the right lift-duration-timing to produce the Hp numbers. Poor choice in cam can ruin a decent setup!

Boy you are really right on this one. I built a twin turbo small block for my buddies duster and it wouldn't clear the 300hp mark at the rear wheels! A cam change later it was a different car altogether!