[GTOGEORGE]

Originally Posted by Tom Vaught

Since the Butlers and Travis Q (as well as Marty Palbylin, in 1996) run high boost (that is 45 to 75 on a typical engine
and the Tractor Pull boys with the diesels are over 100 psi of boost with their stuff, it is not worth my time to explain the difference between a 88 or 91 mm Turbocharger and a 8-71 roots blowers capabilities.

You have a large engine, you have a poor efficiency supercharger (50-55% typically) and you don't spin the thing very high rpm so you make 11 psi of boost pressure and run low 8s. Your supercharger will live for years racing at those boost levels. (unless you do something stupid).

Charlie66 could run 38 psi of boost pressure on a 400 cid engine and make 300 more hp with his small engine vs your 525 cid engine. Which is 125 cubic inches bigger just by adding more boost pressure vs what you run).

Marty could run 6.96 with old school diesel turbos in 1996. It is now 23 years later and you are happy running low 8s and making a lot of passes with your combination. Marty was in the mid 40s on Boost Pressure if I remember correctly.

Mahovitz with a 281 CID engine and high boost 75 psi range runs in the 5s with a door car in the quarter mile. Your Roots system on his 281 cid engine would be a POS.

So read some books on Turbochargers George and then post up and I will try to answer more of your questions on the difference between the two boosting devices. If I explained a Turbo Map to you, then you would understand that a turbocharger (TO BE HIGHLY EFFICIENT AT MOVING THE AIR - must to be over 70% efficient) and the impeller has to spin 75,000+ rpm vs your Roots deal spinning 7500 supercharger rpm.

Tom V.

Sounds like your double talking.....that’s ok you just answered my question! LOL!


GTO George