Baldturbofreak

I'm not calling him (It's Not me!-yet) into the spotlight, But I happen to know of a certain Stripped out roadracing vette that is getting rid of it's Lt-1 for a full tilt 4g63T. Thats right a Mitsubishi 4 banger. There are off the shelf parts for adapting them to rear drive/chevy bolt pattern and he's keeping the ZF-6.
It will eventually have staged compound turbo's for 50psi on alky. The smaller of the two GT2876R is sized for a 2300rpm spool. It's fed by a Supafreak (85/75 hybrid) that will hit round 4k.
This way it will behave like a large NA motor thanks to the smaller fast hit turbo providing the intial 2-1 pressure ratio. It also has an internal gate the dumps into the 5 bolt outlet. All exhaust routes to the T-6. When he comes off the corner it'll hit with instant torque, then the big turbo hits another cool stress free 2-1 on top of that for big (1000+) straightaway power.
The math on stage turbo's works like this = (14.7(one bar) x pressure ratio x pressure ratio) - your local absolute pressure.
In my case it's pretty close to sea level so (14.7 x2x2)-14.7 = 29.4 psi guage on it's "mild" setting. Since the wastegates are dual port and referenced from inlet to outlet, each stage operates at whatever pressure ratio you set it at. A little extra honk can be had at any time from either or both stages.
From one- (14.7x2x2.1)-14.7= 47psi guage
Or from both-(14.7 x2.1x2.1)-14.7 = 50.1 psi guage!
Since only a small change is required in pressure ratio for a large increase in boost, this allows me to precisely size each stage to stay in the ideal island most if not all of the time.
Intercooling on the first stage is optional considering the fuel used.

You figure the car is going to be-
200-300 lbs lighter on the nose
Move the mass back and down considerably.
750-1000 whp (more than 1400 has been had from the 4g63T)
2500-10K rpm usable powerband

What do you guys think? Is he crazy?
I think it's cool as hell and Im backing the project's induction/electronics systems.
Some folks think the 4 banger is Blasphemy, let alone the Mitsubishi. But for the $$ that little motor really puts it down and holds together.
It sure has got me thinking...
corvette's used to come with I-6's, TurboBlueflame-6? You know those 4.2I-6's have a front diff in the oilpan.....

JLeatherman

The sound of a 4-banger in a C4 vette would probably make me retch.

I'm sorry, but I can think of no more fitting quote than:
"There's no REplacement for DISplacement"

Bruce

Well. I don't know what to say of the 4 banger in the C4. But the quote NO REPLACEMENT FOR DISPLACEMENT IS AN OLD NEWS. In the old days that is very true. But with today technologies that quote is not true any more. You can have a full tilt 4 banger or V6 equip with turbo that can make more hp than the NA V8 ever can.

jburnett

Ewww... And I have a ton of respect for 4G63's so don't read anything into that. A couple of the premier DSM guys are some of my best friends and customers (John Shepherd of Shep Racing and Don Polk of Polk Performance) and I respect the hell out of the little boogers... But there's a reason why DSM's are made fun of constantly with respect to reliability... But, hey, whatever floats your boat.
-Jeb
PS- Crankwalking bastards...

JZ 97 SS 1500

I would drop a 2JZ in first.

JLeatherman

Of course you can. But, if you apply that same technology to the existing motor you'll get even more horsepower. A V6 or 4-Banger on 15psi will not produce the same hp as an equally well-prepared V8 on 15psi.

Baldturbofreak

Indeed friend, but you run out of room and weight fast- see my engine compartment. Since roadracing and handling are the goal, it's more about getting the same HP wth less weight and less cost.

I feel ya on the 2JZ, they can be had for a song and have produced over 1200rwhp on the stock bottom end.

Jeb- he's sticking with the first gen motor (6 bolt) were avoiding the POS second gen(7 bolt)

Hey Bruce- Mike (from New Era Performance) did 676 to the wheels today @14psi with an aborted run(went lean) on your turbo (but with hybrid turbine). And that's through a high stall (4k) auto. If you figure 25% loss that's 845 flywheel. No wonder she went lean (110% duty cycle on mototron 70's+ 2 stages of alky). With proper air fuel and another 1k rpm it should put down over 700rwhp. gives ya somethin' to look forward to this spring.

mn_vette

If this is a stripped road racing corvette then here's what you need to do. Keep the V8 and put the darn turbo's in the passanger seat, build another firewall to enclose them and you've got plenty of room for that.

It sounds like alot of custom fab work, but a nice winter project. I wonder how one of those engines with not as much displacement and rotating mass will do on a rear wheel drive setup. Until those turbos spool its just a little 2.0L or what ever its stroked out to.

Oh, and there is a replacement for displacement, its called BOOST

How high is he planning on reving this engine to? I think the 4 bangers have an advantage in that department.

Baldturbofreak

well depends, he has alot of friends in the industry, some of them with last names like Pauter and Burshur. If they decide to lend a hand with goodies prolly more than 10K.
The hit from the primary stage will be nearly instant above 2K so "low end" torque wont be that far off the v-8.
The one cool thing I think will make this very successfull (besides obvious weight advantages) is the huge huge power band 7-8000 truly usable rpm. He will pretty much be able to stay in 1 gear for most of the track upshifting only on straights.

86VX1

the custom fab work to do the swap is cool, but the tying of a mitsu engine in an american car is awkward. You are putting in a motor from a company that built the "zero" in world war II, into america's coolest sports car. some how that does not mesh well.

if would a little more cool if the engine was a turbo ecotech on 50 psi, at least that's within the bloodline.

but major kudos to the guy doing it. the domestic guys will be asking why did you not just get a v8 and who knows what the import guys will be asking. obviouly it does not matter to the owner. it shouldn't matter anyway, since he is paying for it. so to each is own.

i know i would not want to be parked next to this guy at a corvette show, no matter how fast the car is.

LTxDave

I think the little DSM's and EVO's are cool cars in their own right, but that would be the last engine I would consider swapping into a Corvette. There is a 900+ WHP EVO in this area (built by AMS), but I'd rather have my Corvette.

jburnett

Buschur is a bad word in my neck of the woods...
-Jeb

lcvette

I would say he is taking the wrong approach and if he wants to build a monster lightweight 4 banger he should look at a different platform but it would of course be a fun project...

I would use a late 80's early 90's RX7 platform as those cars handling is incredible being based of the porsche 944 which is known to handle like its on rails.. and its lighter!

Chris

BrianCunningham

Must have saw the Mustang with the Supra engine in FF3-Tokyo Drift

You could make a lawnmower engine make a 1000hp with a turbo if you could make it strong enough. But then you'd still have a lawnmover engine.

tpi 421 vette

BTF, I am sure you have the knowledge to pull it off... but a Mitsubishi engine in a Vette just seems wrong to me.

Baldturbofreak

It started at the opti and spread like a virus! LT-1 owners beware!
Dare to be different It's about trying new stuff, I think. We all digg when folks dump a SBC into a 240Z or RX-7, this is merely going the other way. He likes his Vette chassis, you gotta admit when you add cage they are very stiff and well suited to short track roadracing. This project isnt one that was set out to be a 4 banger in a vette, it just evolved that way when looking at a purly engineering point of view. (and dont think engineers don't have budgets deciide what parts to use)
The lt-1 is proven as is the SBC, so is the fact that it weighs around 525lbs dressed. Add even a minimal turbo/blower sytem and you have another 75-100lbs on the nose. The polar moment of inertia when viewed from the top increases very quickly as you add weight to the very ends.
This experiment will centralize the mass a good deal, and reduce roational mass a great deal. The 4g63T is around 22 inches long. aLOT shorter than the SBC. Turbo's and all it will be round 300lbs. thats light for 900+hp It will also get shoved right against the firewall.
If the budget wernt in the equation, it might just be that it would be an ecotech. Or at least a 88-93 quad 4 based off the GMPP block of the day.
But he can get a running 4g63T from a friend, the turbo's and system fab will come from me. Lets say pistons wont be an issue for him, rods from another name - you get the idea. What can I say some of us folks love weird shiit and are willing to throw in a hand.
It makes for good conversation anywho!


BrainC- if your suggesting we warm over a DIXIE Chopper v-twin and drop er in your vette IM IN! wait no lets build a V-4 for er' we can join a pair up at the crankcase. Or even more lungs- a air cooled v-8? V-10 v12?

I 'd dig a flat crank aurora motor myself. spin up to 11K+ yee haw!

86VX1

hey brian, it was a nissan skyline engine in the mustang.

Baldturbofreak

aaah the infamous rb26det. I will give it to the japs on some of them turbo motors. wildly overbuilt.
I warmed over the tune on a Rb20det (it's early predicessor like sbc/ls-1) It was it a 240sx, pretty neat little setup. anywho it came to me knocking like crazy. He'd been driving it like that for months! and it still had less than 2% leakdown hot!

BrianCunningham

The Corvette no, but I'm seriously thinking of picking up an old FormulaFord and building one of these for autocrossing

Brand-X

I need to take a shower now that I've thought about putting an import motor into my vette.