Torque Convertors/Turbo Combos-Real World Results

[Scoobum]

The biggest question I get is, why is my MPH off from ET. 9 times out of 10 they're running a LU convertor unlocked...at it's slipping like a whore on the big end. I'm well aware of RPM drop at the shift points and what the convertor flashes to on launch as being critical...but I'm gonna post the best of what I've seen in regards to how well the convertor is coupling on the big end. All engines are stock stroke with good heads.

Scoobum-11.5 at 121 for Street Class. 6.7 at 105 for Sportsman Class. Turbo 6262. Convertor. Art Carr 16930

Norbs-10.3 at 134. 70 P Trim with large exhaust housing...poss ibly .91. Precision multidisc 2800 LU

Grumpy-9.97 at 138-6776-9/11

Brandon-11.01 at 123-6131 DBB-Off the shelf 2800 PTC NL

Rich aka Bird-9.68 at 138-70 GTQ-Art Carr 19930

JB Racing-10.2 at 13x-70GTQ-Art Carr 19930

Bison-9.97 at 134-6265-PTC 9.5

Jim aka gusszgs-11.4 at 117-60 series-Husek 3021

Dan Keller-11.5 at 123-6262-PTC 9.5

[Grumpy]

Ours is a 9/11 LU  9/11 is sitting with an old motor an trans. Her new set up is a stroker with a PTC NL. Still hung up on LU's here unless your trying to get every single 100th out of the car 

[Forzfed]

Dan, did you do a run with it not locked up?  And if so what was the ET and mph difference?

[reality]

Dan, did you do a run with it not locked up?  And if so what was the ET and mph difference?

And how does that compare with a good nonlock?  ET and mph

[Scoobum]

Ours is a 9/11 LU  9/11 is sitting with an old motor an trans. Her new set up is a stroker with a PTC NL. Still hung up on LU's here unless your trying to get every single 100th out of the car 

Dan...the reading I've done says you really have to buzz the RPM's to maximize a stroker. Any truth to that with you guys.

[earlbrown]

With a longer torque arm, I'd image the opposite is true.

[Forzfed]

Ours is a 9/11 LU  9/11 is sitting with an old motor an trans. Her new set up is a stroker with a PTC NL. Still hung up on LU's here unless your trying to get every single 100th out of the car 

Dan...the reading I've done says you really have to buzz the RPM's to maximize a stroker. Any truth to that with you guys.

The opposite is true.  You will make more hp and torque but in a smaller range.  A destroked motor won't make as much peak hp and torque but will do it over a bigger rpm range, I believe.  Earl?  Earl?

[Grumpy]

Damm... from what I remember we were goin 5500 on the Mazda motor she had. New stroker I want to say around 5800. We have grunt motors. Low rev's more boost.

 Lu gained 4mph and a little over a tenth from what I remember. Just locked it in 3rd.

old age sucks 

[ULYCYC]

Ours is a 9/11 LU  9/11 is sitting with an old motor an trans. Her new set up is a stroker with a PTC NL. Still hung up on LU's here unless your trying to get every single 100th out of the car 

Dan...the reading I've done says you really have to buzz the RPM's to maximize a stroker. Any truth to that with you guys.

The opposite is true.  You will make more hp and torque but in a smaller range.  A destroked motor won't make as much peak hp and torque but will do it over a bigger rpm range, I believe.  Earl?  Earl?

But nothing sounds as good as a 327 destroked to 301 with a 283 crank shifting at 8500rpms

[Steve Wood]

Before that, we bored 283 blocks an eighth of an inch to get to 301.

[Steve Wood]

Ours is a 9/11 LU  9/11 is sitting with an old motor an trans. Her new set up is a stroker with a PTC NL. Still hung up on LU's here unless your trying to get every single 100th out of the car 

Dan...the reading I've done says you really have to buzz the RPM's to maximize a stroker. Any truth to that with you guys.

The engine is just a big air pump.  A stroker will flow more air than a stocker IF the heads and cam will allow it.  If the cam and heads are identical, then the stroker should produce more air at a lower rpm and maintain it over a broader rpm band whereas the stocker must turn a higher rpm to flow the same amount and will be usually produced in a more narrow rpm band.

Depending upon the the construction of the engine, a stroker will often face rpm limits below that of the stocker in order not to fly apart. 

In the real world, if money is no concern, the heads are often the limiting factor as it gets hard to build heads with ports large enuf to handle the flow of a high dollar stroker.   Maybe someone should invent a turbocharger so the air molecules could be compressed and more air could go thru a given port?

[Forzfed]

But nothing sounds as good as a 327 destroked to 301 with a 283 crank shifting at 8500rpms

My buddy's brother who currently is the winningest Canadian racer in the NHRA runs a destroked 327.  There is a local shop that the owner has NHRA records that still stand today, Fastest small block, first small block over 200mph and a bunch more.  I remember him telling me he thought something was wrong with his tach because he couldn't get the revs past 10k, then someone grabbed the tach and broke the stopper off of it!

[TexasT]

Five digit revs is winding it tight. I guess those f1 people do it but they pretty much have an unlimited budget.

[earlbrown]

Keep in mine, a ''higher'' revving Buick V6 is still a pretty slow turning engine.


If the ports are maxed out and you throw in extra stroke at the same RPM, the engine won't swallow a proportionally larger amount of air.   If the compression ratio (and flow numbers) were to stay the same the law of diminishing returns will rear it's ugly head.

If the heads can handle the extra cubes, then the extra cubes will make extra power.


On fantasy land, Steves ''turbo'' idea that would compress the air and let it flow through ports easier would work too.      I guess he got that idea when shrink rays were all the rage in 50's comics. 

[Steve Wood]

You must be a comic book collector.  I learned all I know from Red Ryder and Flash Gordon