Converter flash vs. Peak torque

[Rusty Davenport]

Where is the target flash point on a super stock engine that produces peak torque at 6000 rpm ?? Do you want it to flash beyond the peak torque, dead on the peak torque or less than the peak torque ???

[Ultimate Converter Concepts]

Hi Rusty, A good starting point would be approx. 2-300 over peak torque. But a lot depends on heads, cam, intake,etc. and where the engine is happy as each combo is different. Hope this helps.

Lenny@UltimateTC

[Don Whitmore]

Originally Posted by Ultimate Converter Concepts

Hi Rusty, A good starting point would be approx. 2-300 over peak torque. But a lot depends on heads, cam, intake,etc. and where the engine is happy as each combo is different. Hope this helps.

Lenny@UltimateTC

In general, why would you start with the converter flash OVER the engine peak torque point? Peak torque is where the engine is 'happy,' right? The best engine volumetric efficiency is at peak torque...

[Mark Yacavone]

Don, because true stall is a static measurement, but when you leave the line, that's not the case.
Lenny is correct as to what works.

[Ultimate Converter Concepts]

Originally Posted by Don Whitmore

In general, why would you start with the converter flash OVER the engine peak torque point? Peak torque is where the engine is 'happy,' right? The best engine volumetric efficiency is at peak torque...

Hi Don, By starting approx. 2-300 over peak torque you don't risk having the converter fall back below peak torque, most will fall back 1-200 rpm's after initial flash, and risk having the engine lag getting back to where it makes peak and above. You also don't want the engine to fall back to below where it makes good torque on the shift. This general rule of thumb should keep the engine "happy" as far as coupling at the meat of the torque curve and allowing the engine to create maximum acceleration(engine speed)through it's usable RPM range.With all the different combination's there are, even in the same class with the same specs, every engine is different and the converter should compliment that particular combo. The old adage is true with converters, one size does not fit all. If you want you can call me at the shop during the day, I would be more that happy to try to answer your questions personally.

[Dave Goob Cook]

HP (mathematically calculated number using torque over time) will accelerate the vehicle more quickly and smoothly than the peak torque, especially since you have all the torque multiplication you need up to the point of being "coupled", with a good race converter.

I look at launching at peak torque as being like hitting the car with a hammer to move it, then it recovers and accelerates again.
Using the HP peak to accelerate the vehicle is a steady pull.

[SSDiv6]

Originally Posted by Dave Goob Cook

HP (mathematically calculated number using torque over time) will accelerate the vehicle more quickly and smoothly than the peak torque, especially since you have all the torque multiplication you need up to the point of being "coupled", with a good race converter.

I look at launching at peak torque as being like hitting the car with a hammer to move it, then it recovers and accelerates again.
Using the HP peak to accelerate the vehicle is a steady pull.

Only in theory. You have to take in to account the converter fin design.

[junior barns]

trying to understand??

example only! peak torque @5000 peak HP @ 7000

Where should converter flash??

[Joe DeMarzo]

Rusty, we work exclusively with Ultimate Converters/Lenny. Ultimate converters is one of the key reasons we have been able to go fast quickly with our new combo (having Brian Tilburg also helps). Lenny is one sharp dude and great to work with. Comes to alot of the races in D-1 and is always tinkering. Lenny ran/worked on Super Stock Hemi cars for years. Call him and judge for yourself.

[Ultimate Converter Concepts]

Originally Posted by junior barns

trying to understand??

example only! peak torque @5000 peak HP @ 7000

Where should converter flash??

Hi Junior, Hypothetically you would want approx 5200RPM stall. Most N/A dyno sheets I see have around a 1200 to 1800 difference in torque peak to HP peak (ie - 5200 torque - 66-6800 hp peak). One of the common theories is to try to have your stall 1500RPM below your shift RPM, which should be close to what a particular combo needs to get down the track fairly decent. But again, every combo is different(ie.-bore,stroke,heads,cam,intake, etc.) trans type and gear ratio play a huge part in the equation also. That is why a one off piece, given all the variables,built exclusively to suit your combo will be in your best interest. Remember the converter is just one piece in a well running,well thought out combination. Hope this helps.