The 24 Hours of Lemons Forums → The Airplane-Powered MR2 → Never before has so little power been made from so much displacement!
Ya gotta throttle it somehow....for a gas engine, I'll go piston-melting lean as you back off the fuel flow, until the mixture is so weak it'll be hard to ignite at all. Those two-stroke Detroits are still running in city buses up here...love that blower whine..
I've never heard any blower whine or turbine whistle on any of the -71s or -92s I've worked on, just the rattling sound of compression ignition.
Are you using an automatic? Torque converter? This would top the Wartburg and Dauphine for wackiness..
right now, the drivetrain is as follows:
airplane engine -> custom v-drive made from nascar style cheap quick change gears -> 1 ton diesel transfer case range box running backwards (steps up the RPM by 2.71:1) -> standard automotive flywheel/clutch -> manual transmission -> independent rear end -> custom axle shafts -> stock MR2 rear knuckles
after inspecting all the internals, we're bringing the red-line up to 3000RPMs (up from 1750). it looks like everything will take it. the stock red-line calculates out to 95% the speed of sound at the prop tips for the operating ceiling of the PT-22 plane so I'm assuming the stock red-line is artificial.
stock is 600ft*lbs & 160HP. with the more efficient intake tracts and higher red-line we're expecting 250-300HP and the same 600ft*lbs
which means the transmission will see 220ft*lbs input torque and 8100RPMs max. this should be acceptable inputs to many transmissions.
we haven't picked the exact transmission yet, but we're leaning towards an audi FWD model right now. porsche makes some good ones also for this application but they tend to be more expensive.
I would not be caught dead driving an automatic. there's no excuse no matter how crazy the drivetrain 
Wow. Post pics if you get a chance! Are shock loads an issue?
Wow. Post pics if you get a chance! Are shock loads an issue?
I will as it comes together. right now it's a pile of parts. I'm still working on getting the engine started.
I'm not sure which shock loads you're talking about that may be a problem.
the quick change gears are designed for over 2000ft*lbs of torque and they'll see 600. the reduction box will see about the same 600ft*lb input but is rated for over 3500ft*lbs input and 9500ft*lbs output. granted I'm running it backwards but i won't be coming close to those limits.
the transmission will see 220ft*lbs max and I'll make sure it's rated for it.
i plan on taking the car to the drag strip a few times to test everything before the Lemons race. and to get some cool videos
I was thinking about the loads running back through the system off the line when you dump the clutch but it sounds like you have it seriously beefed up.
I was thinking about the loads running back through the system off the line when you dump the clutch but it sounds like you have it seriously beefed up.
yeah, the last thing i want to do is shatter the drivetrain.
the output shaft on the motor is 2.375" around. which ends up dictating the size of many things in the line. it would be hard to make this thing weak.
honestly, i doubt this thing could be an IOE contender. with the permission to blow the budget without penalty laps because of the craziness i doubt they'd want the storm that would come down on the judges from other IOE contenders if they let this thing win.
the best part about this whole thing is i plan on street registering it also damn i love living in Indiana!
That is f-ing ridiculous. Good luck, Marc! We'll be pulling for you! Hope to see it in Joliet.
honestly, i doubt this thing could be an IOE contender. with the permission to blow the budget without penalty laps because of the craziness i doubt they'd want the storm that would come down on the judges from other IOE contenders if they let this thing win.
Are you freaking kidding me? The other IOE contenders will LOVE this thing, even if it is their "competition" for the IOE title. You are very seriously underestimating the love for mechanical absurdity that is particularly virulent among IOE contenders. Seriously. They will all love you for even trying. And Jay and his crew will too; here's a quick story.
The Yellow Submarine Dauphine/Sable broke a halfshaft the week of the ECR race and wasn't able to compete, but they brought it out to the track on the trailer anyway. I saw it from a bicycle while riding up to HQ to pick up something or other that one of my teammates left there by accident earlier in the day. Jay was in HQ when I got there and I mentioned to him that it was out there, and I could hardly get the words out before he sprung from his chair with vim and vigor to see the thing. And then he was all over it once he got outside, couldn't wait to get the full package tour of the thing.
Not that it sounds like you need a lot of motivation to keep plugging away on this, but there's nobody seriously involved with this series that will give you any crap about trying this monstrosity. Good luck!
PS. FWIW, airflow over the back of the MR2 totally sucks. Somebody's done some CFD analysis and the summary is that you've got basically no good airflow either above or below the engine bay, it's all super-turbulent because of the notchback style of the rear window and c-pillars. So make sure that you make some provision for getting some better airflow through there to cool that sucker down. Check out this thread with some really intriguing graphics for more info:
http://mr2oc.com/printthread.php?t=250308
I'm fairly familiar with the MR2s, I actually own 4 of them.
cylinder cooling will be handled two ways:
1)forced air flow. probably with a set of electric fans and shrouds that will be a pain to build.
2)water injection coupled to cylinder head temperature sensors.
water injection coupled to cylinder head temperature sensors.
Now were talking fancy! I can't wait to see / hear it!
Marc wrote:water injection coupled to cylinder head temperature sensors.
Now were talking fancy! I can't wait to see / hear it!
heck, it's not that fancy. the water injection ports are actually machined on the intake runners from the factory. it was a stock performance adder.
unfortunately my motor came with the ports plugged, i do not have the factory injectors but a modern nitrous injector fits perfectly in the port.
I'm fairly familiar with the MR2s, I actually own 4 of them.
LOL. And you're entering one in Lemons anyway? You are crazy!
Marc wrote:I'm fairly familiar with the MR2s, I actually own 4 of them.
LOL. And you're entering one in Lemons anyway? You are crazy!
hey, they aren't all salvageable. Lemons is a good way to retire the ones that aren't salvagable.
My daily driver is a 1994 MR2 with the new Toyota 3.5L V6 with a few tweaks to get it to 340HP. It's a ridiculously fun car.
Then i have a 1993 that I'm working on turning into a serious race car. shooting for 450-500HP to the ground.
followed by a 1986 that I currently race in Lemons with the 2010 Camry 2.5L 4 cylinder.
and finally, the 1991 that is getting the 8.9L radial engine.
yes, i know i have a problem. but my solution is a very understanding wife!
Buzz Killington wrote:killerken53 wrote:I don't know how well a steady-state engine like this rotary will respond to the constant throttle inputs needed in a car of any form......
likely the same way the gas turbines used on hovercraft do...badly.
yes, the stock system would not respond right, but we aren't running the stock ignition and carburation system.
the motor will still have significant amounts of inertia, but we believe it will be more than drivable
i didn't mean to imply you couldn't make it work, and that it can't work just fine; only that it won't like it. but then again you're not looking for 100,000 miles out of it.
Marc wrote:Buzz Killington wrote:likely the same way the gas turbines used on hovercraft do...badly.
yes, the stock system would not respond right, but we aren't running the stock ignition and carburation system.
the motor will still have significant amounts of inertia, but we believe it will be more than drivable
i didn't mean to imply you couldn't make it work, and that it can't work just fine; only that it won't like it. but then again you're not looking for 100,000 miles out of it.
it doesn't matter if it would work or not, the motor did not come with the magnetos or distributors. makes it a fairly easy decision to make.
100,000miles. HA! this thing has service intervals measured in hours that i can count on my hands.
every 2hours the rockers need greased.
every 5 hours the cylinder hold down nuts need to be retorqued. (yeah, that's gonna be a long pit session)
every 10hours, the valve guides need to be oiled.
and the list goes on.
I'll consider it a success if we get less than 4 hours of pit time in a weekend of racing.
*BUMP*
Any updates?
*BUMP*
Any updates?
I've been working the last 6 weekends on the custom transfer case for this thing. i should post some pictures but not tonight since it's at the shop and i'm at home.
It's a combination unit that reverses the rotation direction and steps up the RPM 3.72:1 and has a PTO output.
the PTO output is running at the stepped up speed and i may use it for cooling.
this means i don't have to think about over-revving the engine anymore. i'm shooting for about 2100RPMs at the motor which will give me about 7800RPM at the transmission input.
i've also changed the transmission from a porsche unit to a subaru unit due to cost reasons.
So much win. I really hope this thing is on track with Speedy's GLCOAT project some time this year. The noise! The glorious noise!!!
Probably too late: this should go pretty well with a Saab transaxle, actually. The transmission is chain drive, so if you mail-order the right sprockets and chain, you can have any gear ratio you want. It's north-south, too, so you're not stuck with the engine sitting at one side of the car.
What's the idle speed of one of those motors?...
... One of my favorite cars of the dawn of automotive era is Mercedes 35hp. 4 cylinders, 6 liters of displacement, idle at 300rpm, full power at 950, redline at 1000rpm. Awesome.
it's a bit late to change the transmission on this project but i'd like to hear more about that saab transmission.
I've got some progress pictures but i have to apologize ahead of time. i only brought my cell phone, i should have brought my digital camera.
first, we have the custom shaft that was welded together, it's a combination of a casale V-Drive output shaft and a Borg Warner 1350 output shaft. the lump in the middle is the 1350's stock oil pump with the guts reversed so it pumps properly.
this fits into the adapter housing between the two boxes:
then the planetary goes on:
and then the planetary gear case to hold it all together:
the whole lot bolted together:
You can see a quick demo here to give you an idea of just how much of a ratio step-up this box provides: http://www.youtube.com/watch?v=jvtMGwLhyQQ
awesome! it's taking shape and I'm getting giddy. any planned debut race?
awesome! it's taking shape and I'm getting giddy. any planned debut race?
I would really like to make the gingerman race this summer.
Toto, I don't think we're in Lemons anymore.......
Toto, I don't think we're in Lemons anymore.......
It's not nearly as bad as you think
i think i have about $40 worth of aluminium and the v-drive cost me $200. the transfer case was free.
Now the labor... that's free
The 24 Hours of Lemons Forums → The Airplane-Powered MR2 → Never before has so little power been made from so much displacement!