thanks chrome!, Just spoke with a friend of mine and he also reminded me of the simple fact of how much fuel { Nitro } is used today to make a pass, compared to the amount burned years ago is a direct indication of the shear increase in H.P. output of these modern day T/F cars.
Cool, I didnt figure he would be off on his information, very smart dude, wish I could get in contact with him, hell Ive been out of school 6 years now so the info he was telling us then could have changed drastically since then as well. -Justin
With the blower, I don't think you're looking at anywhere near the conducted heat you get from the hot side of the turbos. Again, for drag racing it shouldn't be that big of an issue.
Actually ,conducted heat from the exhaust side is a very small portion of the the temperature rise; most of it is from the work of squeezing 3 pounds of air in a one pound bag :-0 Heck, get a bicycle pump and try pumping up a car tire sometime
Turbo technology has come a long way since then, now you can get them that spool so quick it will make your head spin. Several race teams playing with hair dryers back then some made 'em work and others didn't. I think for a lot of fellas the roots blower was just easier.
I used the " Progressive " technology principle as well. A smaller turbo spooling a larger one- what lag?
The radial bike with a few tweaks would be pretty slick, it looks like a whole bunch of knuckleheads welded together.
I would use the squirt technology. Point a nitrous nozzle at the impellor blades to spool it up real quick. No LAG. LOL. Lippy
I'm with you on that one Lippy, my favorite bottle besides Jim Beam, I was afraid to use the " N " word again on the HAMB
Or you could just not leave @ idle, sometimes when you bring the revs up on the line it will get you that much closer to being spooled. I adapted a paxton turbo off of a Corvair to a harley with another fella once, not being blow through it was a little more prone to turbo lag than a blow through system, you could nail it and it would just take off like a normal bike and when the turbo spooled you had better be hanging onto your ass. OK off topic, there were guys way back when that were tunning geniuses they made it work and the rest of the fellas just wished they could.
I'd place good money on the 850 HP hemi would be over 1100 HP if you could spin the blower with an alternative source. Compressing air takes serious HP. Look at how much HP a shop compressor requires for 1-2 CFM. Now compress 1500-2000 CFM.
As for the "lag" issue. You should take a ride in a properly set up and tuned turbo car. Turbo lag can be minimized to a point that it is virtually non existent. Even more so with EFI. I have a 2 step rev limiter that lets me build 3-4psi while staging in neutral but that is way OT.
MUCH easier than with mechanical FI and a mag... Don't you just love coil on plug ignitions??? When Mark Donohue brought turbos to big time road racing in the early 70s, the drivers had to have the throttle on the floor as they ENTERED most corners. Anti-lag has taken all the fun out of driving them...
I really don't know much except the engine had a compression ratio of 8.5-1. I'm sure there was a cam change but don't know what it is. There was also a bit on this engine back in the 70s. Adams said the motor could take 50 lbs of boost and the bottom end could withstand it. My avatar shows Gene working on it on the dyno. Bill
Using a turbo is like the opposite of driving up to the mountains. As you get higher there is less pressure on the intake and the exhaust. A turbo makes the engine think it's several thousand feet below sea level
You went from 400 drag in your first statement down to 250 hp parasitic drag on a gas 850 HP motor. That's still still 25% You seem to know turbos, What's your guess on what size those are on that hemi ? What's the out put of 2 of them turbos vs the out put of 1 671 or 871.
Before this becomes a pointing match, and a freak-out thread, I would LOVE to know more about the engine of discussion if anyone has any additional information about it. Or even about the one on Ferg's floor. Definitely some insane performance stuff for the time!
I'm putting one together now. 10-1 compression will run E-85 with a max of 8 lbs boost and intercooling. Being it will be controlled by Megasquirt, any detonation issues should be handled quite nicely. Will just be for the street. Bill
I'm using your information for reference, not directing this at you TR. That would be a 14-71 at roughly 50 psi boost with 1.7:1 air/fuel ratio. Roughly 10% to run the blower. Compare that to a gasoline-burning supercharged engine that will require a 11.5-12.0:1 a/f ratio, with 6 or 8 71 making considerably less boost than 50 lbs. With the 850 hp engine , No where near 400 HP or even 250 HP to turn that blower on a 850 HP engine.
I meant to type 1200 in my second post. I look at it this way. Each cylinder in the motor is going to make the same HP @ 15 Lbs of boost wether it comes from a turbo or a blower. What comes off the back of the crank after parasitic loss is what answers the question. Turbos create back pressure that is a loss as well. I remember a funny car with huge tanks of compressed air to supercharge the motor in the early 70s. For some reason I think it was a Mickey Thompson experiment. That would obviously be the best situation as there would be no parasitic loss, only the added weight of the tanks.
I also seem to remember the old B&M roots type blowers needing 150-200 HP to spin at max boost and they are less than 1/2 the displacement of an 8-71 The figures I seem to remember for roots type blowers are 50-58% efficency at 15Lbs of boost meaning if it adds 400HP it loses 200HP spinning.
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