The 24 Hours of Lemons Forums → The Twin-Engine MRolla → 2x Engine MRolla Unveiled
If both ends were automatics, you could somehow mod the valve body on both to manual shift, so you can choose what gear to be in on both with the same lever. Of course this assumes both are the same gearset and final drive.
Paul, between this and the Fiat, I HAVE to come see you guys on your home turf. Maybe cook up some BBQ while I'm there....
What you need is a single turbo for BOTH engines -- essentially something matched for 3.2 liters at 6000 rpm -- so look for a small junkyard truck turbo - and that way when one engine is shifting the other continues to supply exhaust energy to keep turbo spooled - sort of the ultimate anti-lag.
Seriously wicked - and I've always wanted to do a twin engine - but was thinking about a Fiero/Bonneville - something with some serious Detroit iron involved...you know..for reliability...
As far as syncing engines...if you had two e-throttle engines, you could (somewhat) easily build a micro controller to compare rev and trim the throttles so that both engines are always at the same RPM, using a single pedal.
MR2 auto is a 3-spd and pretty tall. It'll probably stay in second a lot.
Our teams briefly discussed this exact plan, since we have MR2s and the FX16, but both cars were and are still viable race cars with separate owners/drivers so we never really got around to it. I can't wait to see how this experiment goes!
Personally, I'd rig the 3 speed auto to stay locked in gear (2nd or 3rd, depending on the course). That way it's not hunting up and down each time you let off the gas to shift the front trans, heating up, and crapping out. Most tracks here can be run mostly in second with a 3 speed, though it depends on your ratios and tire size of course.
Buuut... If one were to use autobox in one gear, wouldn't it be a better idea to just leave one of the engines in 3rd/4th in *manual* gearbox and not even have a clutch linkage? TVIS 4AGE has a pretty broad torque curve; I really don't see the advantage of using a non-lockup automatic gearbox for just one gear - you get extra weight, heat, and torque converter inefficiency, as well as rubbery response. With a single-gear manual, you can mount the shifter somewhere off to the side and just rev-match it as you enter the track.
Our Stanza posted some of the best (for us) lap times when using 3rd for the entire course at CMP.
What if you melded a Corvair to a Honda = Horvair.
Paul, between this and the Fiat, I HAVE to come see you guys on your home turf. Maybe cook up some BBQ while I'm there....
Dave if you come out this way I will definitely make it worth your while, those were some serious eats you cooked up for us at MSR. Judy was absolutely jealous we were eating BBQ without her. Your seat is open in the Fiat when it's finished....
Personally, I'd rig the 3 speed auto to stay locked in gear (2nd or 3rd, depending on the course). That way it's not hunting up and down each time you let off the gas to shift the front trans, heating up, and crapping out. Most tracks here can be run mostly in second with a 3 speed, though it depends on your ratios and tire size of course.
We have been talking to a lot of racers about trans shifting and gearing. One option that makes some sense is to start the manual out in 2nd gear and load the auto allowing it to get us up to speed, using only 2nd and 4th in the manual and 1st and second in the auto. But of course that's all thrown out the window once, if and when we get the damn thing on the track. I like this discussion it keeps reminding me of how mad I really am! Oh yeah and Larry too, the Bastard talked me into this.
Cool! I had been threatening to take two minivans and cut a big 'ol hole the floor between the back wheels and weld in a second engine / subframe with the steering locked ahead, and being the same automatics it would seem simple to make a throttle with dual cables, and the fuel tank is pretty big on one of these things....take the glass out, gut it, lower it and put on some hella sway bars and maybe even cut the roof off and it would be reasonably light, should at least be as fast as 1/2 the field. And RELIABILITY is built in with 100% redundancy. I can't see why any potential problems...not compared to this and the Mr2 with the radial engine!
Then you can call it a Semi Hemi under glass (Lexan that is)
Cool! I had been threatening to take two minivans and cut a big 'ol hole the floor between the back wheels and weld in a second engine / subframe with the steering locked ahead, and being the same automatics it would seem simple to make a throttle with dual cables, and the fuel tank is pretty big on one of these things....take the glass out, gut it, lower it and put on some hella sway bars and maybe even cut the roof off and it would be reasonably light, should at least be as fast as 1/2 the field. And RELIABILITY is built in with 100% redundancy. I can't see why any potential problems...not compared to this and the Mr2 with the radial engine!
That's an excellent idea! GM did something similar with two Citations in the early 80s, and it worked great!
That's an excellent idea! GM did something similar with two Citations in the early 80s, and it worked great!
It was a Citation, how could it not work great
... I like this discussion it keeps reminding me of how mad I really am! Oh yeah and Larry too, the Bastard talked me into this.
Talked into? All I had to do was buy a Corolla.
Judge Phil wrote:http://www.murileemartin.com/LBW09/LBW09-4014.jpg
Always liked this shot of the Volatile RAM car at Buttonwillow '09.
That was Joe. (My story. Sticking to it.)
I should... er, Joe should have a much better time keeping the MRolla on course because it's 4 wheel drive. Logic dictates it.
eh? NOT!
A: I distinctly remember you coming in for your black flag after this little detour.
B: I didn't drive off at that particular Buttonwillow race.
All this fantastically optimistic discussion of syncing transmissions misses the fact that one of the 2 drivetrains WILL CERTAINLY self-destruct within 20 laps.. so it really doesn't matter too much how you sync transmissions since one will be in neutral for 22 hours.
I prefer to think of it as race car with its backup engine and transmission already installed. I've attempted to race mr2s enough to see this as beautiful thing.
Great job Larry & Paul! You really need to abandon SLC and move to Ashland.
-Joe
All this fantastically optimistic discussion of syncing transmissions misses the fact that one of the 2 drivetrains WILL CERTAINLY self-destruct within 20 laps.. so it really doesn't matter too much how you sync transmissions since one will be in neutral for 22 hours.
Such pessimism! I think this setup will magically cure all the reliability problems that normally plague MR2s.
Sideways wrote:All this fantastically optimistic discussion of syncing transmissions misses the fact that one of the 2 drivetrains WILL CERTAINLY self-destruct within 20 laps.. so it really doesn't matter too much how you sync transmissions since one will be in neutral for 22 hours.
Such pessimism! I think this setup will magically cure all the reliability problems that normally plague MR2s.
Exactly, instead of the MR2 pushing 2000 lbs, it only has to push 1/2 of 2200 lbs. Same for the Corolla. Less weight is less strain on the running gear. Plus, think of it as having 280 wide tires on the drive wheels for acceleration. It can't fail. it is pure win.
Cool! I had been threatening to take two minivans and cut a big 'ol hole the floor between the back wheels and weld in a second engine / subframe with the steering locked ahead, and being the same automatics it would seem simple to make a throttle with dual cables, and the fuel tank is pretty big on one of these things....take the glass out, gut it, lower it and put on some hella sway bars and maybe even cut the roof off and it would be reasonably light, should at least be as fast as 1/2 the field. And RELIABILITY is built in with 100% redundancy. I can't see why any potential problems...not compared to this and the Mr2 with the radial engine!
I'm actually in the middle of acquiring an abandoned 95 Trans Sport from the Walmart down the street to do this VERY thing. I also have a free Venture donor lined up as well. But to be honest, seeing this thread has made me not want to do it at all.
Judge Phil wrote:That's an excellent idea! GM did something similar with two Citations in the early 80s, and it worked great!
It was a Citation, how could it not work great
Oh dear god. Well, now we have an alternative for down the road with the Craptation!
All this fantastically optimistic discussion of syncing transmissions misses the fact that one of the 2 drivetrains WILL CERTAINLY self-destruct within 20 laps.. so it really doesn't matter too much how you sync transmissions since one will be in neutral for 22 hours.
-Joe
Boy you are optimistic..... All I want is 2 laps at the start and 2 laps at the finish, anything else is a +++++++++.
I got the last half of that with the V12 t-bird. Nothing more. Double the drivetrain is double the laps, so you should get your wish.
Or just treat it like a spare. Run the stock mid engine hard until it blows up and then finish the race with the FWD. 
Judge Phil wrote:Sideways wrote:All this fantastically optimistic discussion of syncing transmissions misses the fact that one of the 2 drivetrains WILL CERTAINLY self-destruct within 20 laps.. so it really doesn't matter too much how you sync transmissions since one will be in neutral for 22 hours.
Such pessimism! I think this setup will magically cure all the reliability problems that normally plague MR2s.
Exactly, instead of the MR2 pushing 2000 lbs, it only has to push 1/2 of 2200 lbs. Same for the Corolla. Less weight is less strain on the running gear. Plus, think of it as having 280 wide tires on the drive wheels for acceleration. It can't fail. it is pure win.
Now that I think about it: engine in the front, engine in the back = winning up front & winning at back. I think that is "Bi-Winning"!
The 24 Hours of Lemons Forums → The Twin-Engine MRolla → 2x Engine MRolla Unveiled
