The gas turbine powered MR2 build begins (Page 1 of 3)

The transmission & transfer case setup:

The advantage of using the E series Toyota transmission is that it bolts right up in the chassis, i don't need special axle shafts and other potential issues. i'm essentially running an updated version of what the Celica all-trac ran:

the advantage of using the rav-4 box instead of the all-trac box is that it allows a V6 motor with it's extra clearance. and has a more appropriate gear ratio for my application (2.928:1)

the only difference is, i won't be using the AWD center/front double differential. the plan is to weld the drivespline right to the side of the non AWD application differential so that the AWD transfer case can add power strait to the ground.

also, i want to look into the possibility of running the larger drive axles for this application. normally the AWD uses a smaller spline CV since power is distributed to 4 wheels and i do not have that advantage. the bore through the rav-4 box is about 5mm too small at just one section to allow that but opening the box up should reveal if that can be machined away.

so here's the trans and t-case in question:

yup, the transmission looks new because it is. i bought it years ago for my daily driver strait from Toyota after getting a terrible rebuild that cracked my transmission case and when they shipped me the first one UPS was kind enough to put a fork right through the transmission. so they gave me the broken one and sold me a new one. I've since repaired the case by welding the aluminium but i may as well use it for this and i have zero dollars in it.

the plate on the side just unbolts and the rav-4 box bolts on (other than one bolt since they changed the design a bit in 12years (1989 design versus 2001)

and then finally, the gas turbines call for a bunch of safety wiring so i bought 3 different sizes of wire and some safety pliers:

Very powerful cooling solution, indeed.

So then you're committing to dual-fuel?  What are your thoughts on cell location?

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I thought his original plan was to stick all of that in the back where he had the radial, and both using the same gas tank for fuel since turbines can burn pretty much anything.   Not sure but thought it might be the OE tank.

sorry for the late reply guys, the system bliped and i did not get a notification e-mail

it's going in the same red MR2 chassis that had the radial. it's already got a really nice cage in it so it's one less thing to do.

the plan is to have the turbines to augment the power. i could drive on turbines only with the e153 in neutral since it's oil pump is driven by the ring gear, but likely it'll be in triple engine mode most of the time.

yeah, the MR2 is super tight, if they run well on gasoline i'll just use the OE tank. it'll give me about 20-25minutes of runtime between refueling.

you got it, it's all going in the trunk/engine bay. it'll be an exercise in origami! the goal is to get the engine lid to close also, but i won't feel bad if i need to make a hump for the turbines.

i will definitely fit a fuel cell up front if nothing else for use on the street. the only question is if it has to be removed for Lemons. but that's not a discussion for this. it's a safety tech discussion. i don't expect to be able to fit a very big tank.  the brakes and the clutch can move inside the cabin with reverse mounted masters and the power steering stuff can all be removed. with a custom cell there is enough room for 25gal up there. without a custom cell i can probably fit 10-12gal which is the way i'll go. the passenger side floor would be ideal but i think that's an insurance no-no.

also, for what it's worth, i would like nothing better than to run a diesel engine in here. so if i somehow can arrange that coming from the UK, as long as it's the 2AD-FHV so it does not complicate any of the other stuff additionally, i'll definitely go for it.

sure "Post to: United Kingdom" makes things a bit trickier

this wasn't answered directly previously so i may as well do it here.

the v6 will be linked to it's gas pedal in the normal manner. the clutch and the shifter will only affect that engine's power.

the powerglide or CVT will be mechanicaly set to let the revs go as high as possible and only bring gearing in to stop overspeeding the turbines. the snowmobile CVTs already do this, and the powerglide can be set to do the same by essentially leaving the kickdown connected to atmospheric pressure so it's assuming 100% full throttle constantly. there may be a bit more to getting the powerglide to shift optimally but that's the idea anyways.

the throttle to the turbines is the only tricky part. the simple answer is that i make automotive electronics for a living and i'll use that voodoo to do this. the more complicated answer is:

i'll probably map 60-100% throttle on the gas engine to 0-100% throttle on the turbine with the following working envelope:
1) stay above idle RPM
2) don't allow fueling above 50,000RPM
3) don't allow more fuel than the turbine can take based on it's current RPM & compressor exit pressure. (intake air temperature may also figure in)
4) reduce fueling to prevent exhaust from reaching over 1250F

the turbines will have a separate ignition switch and a separate start switch and if i use a powerglide it'll probably have a drive and a neutral position only, no reverse or park.

it'll probably drive a bit funny and take some getting used to, but it should be fun.

you're not entirely wrong, but many cars have an exponential curve on their throttle by design. the reason to not kick in the turbine till higher throttle is simply fuel economy. it's MUCH cheaper to get 150hp from the gas engine than to get 150hp from 50% gas and 50% turbine.

but it'll all be software adjustable and i'll adjust till it feels right.

that's not quite true, at idle it'll be spinning 30,000RPM and consuming about 2-3GPH at 20% throttle it'll consume about 7GPH and at 100% throttle it'll consume about 8GPH. so it's very non linear, but if i can keep the engine idling when i need less than the gas motor's HP i would be better off. treating it like an on/off switch is better. and i'll probably try that also, make it so it goes to 100% when the gas throttle is at 100% and idle when the gas throttle is at 98%

once i get there it should be easy to test different modes out.

I learned not to set the cruise control in my truck if it was raining or damp on the highway after it downshifted going up a hill and started fishtailing on the highway at 75mph.