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Old 05-02-2019, 03:48 PM
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Default Turbo sizing

Im building a turbocharged 440" (4.185" x 4") IAII, with billet crank, billet rods, CP pistons and Edelbrock heads. Looking to make around 1600-2000 hp. Cant decide on what size turbos to run. I can get a pair of Precision 88's form a friend but im not sure if those may be a bit big? Its going to be 8.5 compression and ill probably start out on c16 fuel with a blow thru CSU carb. Will eventually go to a HOLLEY Dominator ECU and alcohol. Thx!

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Old 05-02-2019, 05:05 PM
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For your info, years ago Rodney Butler and Travis Quillen put together a 440 cid engine that was based on a IA-1 Block and a 3.6" stroke. I sold Rodney two of the raw Forged Pontiac 366 short stroke cranks and had Moldex Crankshaft stroke them to a larger 3.5"/3.6" stroke. So the engine wound up being a 440 cid engine.

I also helped Rodney get a pair of the T-91 Turbonetics Turbochargers.

With that combination the engine made 2885 HP on the Dyno with Travis Q tuning the EFI system. Rodney and Travis beat the crap out of that engine in Rodneys 64 GTO drag car. Later they built a 482 engine and installed T-88 Turbos.

So for your deal a 440 cid engine might work out really well with the 4" stroke and T-88 Turbos or even T-76 Turbos. Depends on the Power Level you are after.

The Raven has T-88 Turbos on it.

The highest Blow Thru CSU Dominator Carb HP I have personally seen was made on Steve Morris Dyno during a Blow-Thru carb Shoot-out.
Right at 2000 horsepower with race gas CSU Hat, and Steve Morris tuning. The engine was a BB Chevy.

Nice thing about T-88 Turbos is a good pair of them are able to be tuned across a large HP band.

Tom V.

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Old 05-02-2019, 07:14 PM
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Quote:
Originally Posted by Tom Vaught View Post
For your info, years ago Rodney Butler and Travis Quillen put together a 440 cid engine that was based on a IA-1 Block and a 3.6" stroke. I sold Rodney two of the raw Forged Pontiac 366 short stroke cranks and had Moldex Crankshaft stroke them to a larger 3.5"/3.6" stroke. So the engine wound up being a 440 cid engine.

I also helped Rodney get a pair of the T-91 Turbonetics Turbochargers.

With that combination the engine made 2885 HP on the Dyno with Travis Q tuning the EFI system. Rodney and Travis beat the crap out of that engine in Rodneys 65 GTO drag car. Later they built a 482 engine and installed T-88 Turbos.

So for your deal a 440 cid engine might work out really well with the 4" stroke and T-88 Turbos or even T-76 Turbos. Depends on the Power Level you are after.

The Raven has T-88 Turbos on it.

The highest Blow Thru CSU Dominator Carb HP I have personally seen was made on Steve Morris Dyno during a Blow-Thru carb Shoot-out.
Right at 2000 horsepower with race gas CSU Hat, and Steve Morris tuning. The engine was a BB Chevy.

Nice thing about T-88 Turbos is a good pair of them are able to be tuned across a large HP band.

Tom V.
Sorry Fat Finger 1965 GTO
TV

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Old 05-02-2019, 09:03 PM
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TV,

Car show yesterday i saw a 2-stage turbo in Series added to an modern inline-6 DODGE diesel truck.

The first turbo was the largest id ever seen. 2nd turbo was also big but not like the 1st stage Fella said the 6-cyl made 1200 HP. I forget the PSI value (either 29 or 40 psi) A custom implementation that was as "stock looking as possible". Sure made me look.

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Old 05-02-2019, 09:36 PM
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Very Common HIS to do Compound Boosting.

But in order for that to work well the first in line Turbocharger has to be a lot larger than the second in line boosting device, be it a second Turbo or a Supercharger.

Gale Banks has done a lot of work in this area. 180 psi of boost pressure

https://www.dieselarmy.com/news/gale...unds-of-boost/

Tom V.
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Old 05-03-2019, 12:36 AM
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Thanks for the reply Tom. What size A/R would you recommend?

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Old 05-03-2019, 07:21 AM
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If it was me , id go with a smaller pair of turbos..

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Old 05-03-2019, 07:58 AM
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One of the Polish crowd came over with a '69 Camaro to our doorslammer shootout last year, 4 x 4 drivetrain, it used a SBC with twin 88's, ran easy 7.70's @170 odd mph.

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Old 05-03-2019, 05:28 PM
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Quote:
Originally Posted by charlie66 View Post
If it was me , id go with a smaller pair of turbos..

Can't disagree Charlie, a pair of these T76 from Precision would work well but Harry's stuff is not cheap. (as you know, lol!)

https://www.summitracing.com/parts/p...xoCa18QAvD_BwE

Tom V.

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Old 05-03-2019, 05:42 PM
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Quote:
Originally Posted by Half-Inch Stud View Post
TV,

Car show yesterday i saw a 2-stage turbo in Series added to an modern inline-6 DODGE diesel truck.

The first turbo was the largest id ever seen. 2nd turbo was also big but not like the 1st stage Fella said the 6-cyl made 1200 HP. I forget the PSI value (either 29 or 40 psi) A custom implementation that was as "stock looking as possible". Sure made me look.
Quote:
Originally Posted by Tom Vaught View Post
Very Common HIS to do Compound Boosting.

But in order for that to work well the first in line Turbocharger has to be a lot larger than the second in line boosting device, be it a second Turbo or a Supercharger.

Gale Banks has done a lot of work in this area. 180 psi of boost pressure

https://www.dieselarmy.com/news/gale...unds-of-boost/

Tom V.
I'm not certain of the exhaust setup, as to which turbo sees the exhaust first, but I too have seen the same exact setup on a cummins this past weekend. Something on the order of a 90+mm compressor feeding a compressor of I'd guess around 70mm. The smaller of the two turbos hugged the block while the larger of the two was set out away from the block and foward, where you might otherwise have a battery.

This is what I saw. https://www.alligatorperformance.com...SABEgKn9_D_BwE

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Old 05-03-2019, 06:12 PM
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Two Comments:
The Staged Turbo Stuff has been around a very long time.
The larger Turbo takes less dense Atmospheric Air per Cubic Meter and compresses it to feed the Smaller High Pressure Turbo. If you get a good match the best density ratio is there as well as the much higher Pressure Ratio feeding the engine.

As far as selecting a given turbo size Charlie. The OP said he wanted to make 1600 to 2000 hp. Smaller Turbos will make that 1600 hp with a 406 cid engine (Palbykins).

One of Steve Morris Customers/friends dynoed a BB Chebby 505 engine with a pair of T-80 Turbos and could not make 2000 with that engine and a very good Inter-cooler system using a Dominator Carb.

A different test using Turbos in the T-85 Range got closer to 2000 hp but did not make it. This was on a larger 572 cid engine.

So if you forget about the 2000 hp number T-76 Turbos, T-80 Turbos, and T-85 turbos will all make good power on a 440 cid engine.

Tom V.

I was at Steve Morris Dyno for each of these Test Sessions.

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Old 05-03-2019, 08:39 PM
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Quote:
Originally Posted by Tom Vaught View Post
Can't disagree Charlie, a pair of these T76 from Precision would work well but Harry's stuff is not cheap. (as you know, lol!)

https://www.summitracing.com/parts/p...xoCa18QAvD_BwE

Tom V.
Those are rated for for 1250hp each . I dont see why he couldnt make 2000+ with a pair of them.. My friend made 1050hp with a 6 cyl at the wheels with 1 6870 turbo..

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Old 05-03-2019, 09:04 PM
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Probably could with a $6,000 cash outlay (Harry's $6,000 price tag)
"but Harry's stuff is not cheap"

Those Precision Turbos would have all of the bells and whistles from Harry.
Billet Wheels, Ceramic Ball Bearings, etc.

TV

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Old 05-04-2019, 08:02 AM
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There is a boosted Cummins diesel Nova in X275 , Ryan Milliken, runs 4.28 with a 170 mph terminal speed, I imagine that is compound 'charged. Very impressive.

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Old 05-08-2019, 09:58 PM
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In a 1/4 mile acceleration i figure the parallel twin turbos out-accelerate the Series twin turbos. Am i right?

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Old 05-08-2019, 11:00 PM
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MY OPINION, BASED ON OTHER TESTING, YES.

Some might remember the street car conventions some years ago where people would run their car on a Chassis Dyno and see who could make the biggest number.

A Chevy Friend had a 505 engine with a staged twin Turbo set-up.
The dyno test was just the guy with the max HP, not acceleration or track times.

The Chevy guy on methanol would run Tractor Pull type Boost Pressures and destroy the Dyno Competition Guys but on the track the set-up was really lacking, HIS.

The Parallel Twins were a much better ET type Set-up. Dave was the guys name.

He was the guy who put me on to the E-85 type Sensor capability that would allow judging what the true percentage of the E-85 fuel was at the pump. It used a GM Fuel Sensor and Dave's own "Electronic Box" design to communicate with a lap top computer.

Tom V.

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