Michael_Rudy

Well i have a few first gen rx7s, and not enough time or money to build up a bunch of rotarys. So i am going to build my daily driver with the help of diesel. I am going to be swapping in the 1.5L, 4 banger diesel from a 1984 nissan pick-up. I am also just gonna slap a turbo on her at 10 psi for kicks. My dad did this on his old little nissan he had and was getting over 40 mpg in town. My rx7 is a fair bit lighter, and a bit more slippery in the air. I don't really know how its performance will be, i hope mabye a little better then stock in the excellerating, and a fair bit in the cornering, with the adjustable koni's and stiffer lowering springs.

jgrewe

iTrader: (1)

It worked for Audi at the 12hrs at Sebring...

Michael_Rudy

Opps i ment 2.5L

LT1-10AE

Sweet! A diesel swap will definitely be a different route. I've been thinking of doing the same with my Land Rover.

Black91n/a

You may want to try to do it with a newer motor, for reliability, power and fuel economy. You can likely do better with all of those criteria if you go newer (don't ask me what though).

If you ever get this done I should stop by and have a look at it one day, I'm in Kelowna every once and a while for autocrossing.

SoontobeLS1'd

Cool! Good luck!

Michael_Rudy

Well this engine is at 150,000 km, and i have been searching and it seems no one has blown one under 450,000 km. So i think the engine is in a prime area to turbo, stock the engine makes 68 hp at 3800 rpm, and 107 ft/lbs torque at 1500 rpm. So i figure if i run around 10-15 psi of boost, i should be able to make around 140hp'ish at the wheels, and around 200 ft/lbs torque at the wheels. But the way turbos love to be boosted, and with its higher compression it might even make more

Black91n/a, ya sometime you should definatly stop by i have some neat toys like a 1974 repu, and a 1975 Rx3. Me and my dad also built a first gen drag car with a 302, 4 link adjustable suspention, its pretty neat.

Black91n/a

Hey, that's a pretty neat collection, I've never actually seen a repu before. I'm at UBC now, and I'll be up north working this summer, but I'll be home in Kamloops for a week or so after exams and I'll probably be in Kelowna at least once for an autocross, I'll PM you when I know more. I'd love to see your collection.

I suppose that engine does sound like a pretty good option when turboed, and most newer diesels are huge for full size trucks.

stilettoman

iTrader: (1)

I just have to tell this one. My friend retired to Arizona, then bought himself a new Mercedes 320, common rail turbo diesel. He came to visit and I got to drive it a bit. If you did not tell me it was a Diesel, I would never know. It was smooth, quiet, no smoke or unpleasant odors, and pretty fast. It is a big car, and much faster than the 200 HP would suggest because of the tremendous wide torque band. I think this may well be the way of the future.

He is getting an average of 35-36 mpg. It is about a $55,000 car in the US.

GUITARJUNKIE28

what are you gonna do about the diff?

stilettoman

iTrader: (1)

http://www.carpages.co.uk/mercedes_b...s-14-07-05.asp

That diesel will want to turn a lot slower than the rotary. Even with an overdrive tranny, it may be a problem. You may need to consider an 8 inch Ford. I have one sitting in my backyard with a 2.75 gearset. This is from a Maverick, and is exactly the right length for a 1st gen RX-7.

This is significantly lighter than the 8.8, and much easier to deal with because it is all steel, and you can weld to it.

Michael_Rudy

Ya, i have been contemplating with the question of gearing since i have been looking at other diesel cars. I thought about the 8 inch ford i also had heard you can get lower gears for then toyota pick up rear ends also. I might have to take a couple trips to the junk yard to see what will work.

Black91n/a

There's some options available for taller gears. There's the 3.9 from the autos, and there's been a bunch of talk on the miata boards about using some ~3.3:1 gears from a diesel Mazda truck. I know we can use 1.8 Miata diffs in the NA pumpkins, and vice versa, and this ring gear apparently fits, so maybe we could use those gears in our diffs. Have a look on miata.net and you may be able to find out more information on this.

LT1-10AE

The only drawback to attempting to use a different R&P set from a different vehicle is the RX-7 has an unusually long pinion. You won't be able to toss a 3.54 ring in there and expect it to work - you'll need a matching pinion which is about as long as a baby giraffe's neck.

Nihilanthic

That 3.73 in a 929 carrier thing is coming along pretty well at torque central, but thats still probably a bit too short for a diesel.

Cobra pumpkin swaps have been done before and are only going to get better as information and experience is shared, so there you go.

LT1- cant you just use a longer DS if the pinion is shorter than it was?

fcdrifter13

Holy **** at 3800 redline. Thats screaming for a diesel. If the motor has 150k on it I would rebuild for your aplication. I know about the reliablity of them but, if you start pushing more boost on old internals no matter how tuff the block is and well maintained it isnt gonna like it that much.

Now I am not to sure about your application, but most injectors for diesels run at 60% duty cycle there whole life. Some more some less. Remember you are injecting fuel at (if I recall corectly) 250psi have them checked out, and if there are bigger go ahead and get them.

Again not sure about the engine you are working with, but if you decide to do a rebuild and the enige has liners go ahead and get new liners(of course aftr checking clearences) If you wanted you you could have the block bored and pop in some bigger liners and pistons, wont be much bigger just saying.

And 10 or 15 PSI, dont be a pansy. Put some bigger injectors in that bitch, richen it up and toss some real PSI to it. WE had a stock Mitsu at the shop we played around with. From factory was running 12PSI. Of course we messed with it. Put some injectors out of a bigger mistu in it, adjusted the F/R and crancked up the bost to 35psi. Ran fine, and the mother fucked screamed, OMG at 2900RPM sounded like it was gonna blow up. But it still runs fine.

As long as you have enough fuel, and the block is strong enough(preferably sleved) you can run all kinds of boost. Some stock diesels run about 60PSI and dont have anykind of engine managment, unless you count mechanical governers and things of that nature.

MrFC3S

hehehe... sounds fun... makes me wana find a cheapo Turdo Diesel...

Michael_Rudy

Most of the diesels that are runniung like 60 psi, have like 14-19:1 compression, my little engine has 23:1, also if i get bigger jets and run more fuel i will get way worse gas milage which would be the total opposite of what i am building the car to be.