Joseph Dell
Enthusiast
Folks -
I'm on a quest to _quantify_ the differences between viper setups out there. So I took a look at about 20 different dyno charts from modified NA cars (Lethal) to ROE SC (a few, including some of his posted early test runs, DLM (biggest sample), and Heffner.
It is also worth mentioning that with the exception of my personal car's DLM level 1 first dyno run (560rwhp and 590rwtq) and one of Sean Roe's test set-ups
prior to the VEC2 (565rwhp and 593rwtq), there were very _few_ dyno graphs that wwere even close for comparison.
As a result, I looked at all the dyno charts NOT for the raw numbers themselves, but for the attributes of a DLM car vs. a ROE care vs. the Lethal car vs. a Heffner car.
- Almost all SC HP and TQ numbers cross at 5300rpm
Treynor's DLM car was closer to 5100rpm, but almost all SC cars, regardless of manufacturer, had this occur.
- about 90% of tq was achieved at 3800RPM on all DLM cars.
- ROE Twin screw cars make about 90% of tq at ~2700 rpm, max at 3500rpm, and begin to gradually drop off TQ at 4200RPM
- DLM cars maintained TQ from 3800 until 5100 on cars w/o head work.
- DLM cars w/ head work have increased tq over 5100rpm.
- Heffner SC cars tends to build tq more gradually with less agressive tq curves. Specifically, 3600rpm to 5100rpm is slightly slower than DLM cars.
- All SC cars w/ head work appear to drop off power higher in
the RPM range (higher than 5100).
I wanted an answer to the "what are some differences" with regards to twin-screw vs. centrifugal... Here they are, right from the dyno sheets.
One note on the Lethal dyno sheet. TQ also began to drop off after 4200 rpm... This car looks like it will respond well to a SC.
I hope this info helps a bit! It certainly explains why my car is slower off the line than some, but faster at the end of the track.
Take care!
Joseph
I'm on a quest to _quantify_ the differences between viper setups out there. So I took a look at about 20 different dyno charts from modified NA cars (Lethal) to ROE SC (a few, including some of his posted early test runs, DLM (biggest sample), and Heffner.
It is also worth mentioning that with the exception of my personal car's DLM level 1 first dyno run (560rwhp and 590rwtq) and one of Sean Roe's test set-ups
prior to the VEC2 (565rwhp and 593rwtq), there were very _few_ dyno graphs that wwere even close for comparison.
As a result, I looked at all the dyno charts NOT for the raw numbers themselves, but for the attributes of a DLM car vs. a ROE care vs. the Lethal car vs. a Heffner car.
- Almost all SC HP and TQ numbers cross at 5300rpm
Treynor's DLM car was closer to 5100rpm, but almost all SC cars, regardless of manufacturer, had this occur.
- about 90% of tq was achieved at 3800RPM on all DLM cars.
- ROE Twin screw cars make about 90% of tq at ~2700 rpm, max at 3500rpm, and begin to gradually drop off TQ at 4200RPM
- DLM cars maintained TQ from 3800 until 5100 on cars w/o head work.
- DLM cars w/ head work have increased tq over 5100rpm.
- Heffner SC cars tends to build tq more gradually with less agressive tq curves. Specifically, 3600rpm to 5100rpm is slightly slower than DLM cars.
- All SC cars w/ head work appear to drop off power higher in
the RPM range (higher than 5100).
I wanted an answer to the "what are some differences" with regards to twin-screw vs. centrifugal... Here they are, right from the dyno sheets.
One note on the Lethal dyno sheet. TQ also began to drop off after 4200 rpm... This car looks like it will respond well to a SC.
I hope this info helps a bit! It certainly explains why my car is slower off the line than some, but faster at the end of the track.
Take care!
Joseph