Sep 18, 2020 update to the Toyota MR2 Turbo project car

Project Toyota MR2 Turbo: Let’s Go Autocrossing

Getting our 1991 Toyota MR2 Turbo cleaned up and back in shape wouldn’t feel right unless we found some time to test its limits. A local autocross felt like the perfect venue to assess what we had and where we may still want to go, and it just so happened that the Buccaneer Region of the SCCA was having one of their monthly events at the Florida International Rally and Motorsports Park, just over an hour from our various GRM World Home Office HQs this past weekend.

Our goal wasn’t really even anything as ambitious as sorting, or even baselining, but we were really just doing a basic function check and assessment. Our MR2–even though it has a 60,000-mile-ish JDM motor and transmission–has a 100,000-mile Northeastern chassis and has never really been driven hard. It seems in good shape, but if we’re going to take it to a few autocrosses now and then, we need to make sure there’s a level of safety and competence there.

So after running through the basic SCCA Solo tech procedures a couple days before the event and making sure we had things like solid battery tiedowns, good throttle return mechanisms, decent wheel bearings and working brakes, we loaded the car up and headed for the autocross.

Two runs in and we were already disappointed: Our typically quick-feeling turbocharged Toyota felt slow. Good grip, but not much power. 

Were we just overestimating the thrust it had? Had we been spoiled by years of 400-plus-horsepower V8 project cars?

No, it was much simpler than that. A hose clamp not fully tightened down had led to an intake hose coming loose. No boost meant no power. The clamp reattached and a point scored for hitting a local autocross before you do anything serious with a project, and we were on our way under full available power.


And what a lovely autocross companion the car made. Due mostly to the sticky Falken Azenis RT660 tires on the wide Konig wheels, the car had lots of grip, especially exiting corners. Best of all, we experienced no rubbing or scraping of wheels and tires at either end. That was a nice bonus after we opted for the wider of the wheel options that we thought would work, hoping we wouldn’t have to deal with any interference in our quest for more contact patch.

At the end of the day, we finished 12th overall in raw time, behind a collection of mostly Corvettes and Porsches. Not bad for a thoroughly unsorted 30-year-old car.

That’s not to say we didn’t find some weak points, though. The brakes certainly leave a lot to be desired. Brake technology has come a long way in 30 years, and we’d like to leverage a little bit of that modern technology to make the middle pedal a bit more confidence inspiring. 

We also think there’s some easy, zero-downside power gains to be had with a few simple bolt-ons. Our engine swap was done professionally, but also done with a bit of “mass-production” in mind. So there were a few parts recycled from the donor car that should be able to be easily swapped out for more performance, like the downpipe and intercooler.

Speaking of cooling, heat management is a huge issue on any turbo car. Although we didn’t experience any overheating issues, it’s obvious that a lot of heat collects in the engine compartment. Controlling engine and charge temps will pay dividends in both power and durability, so we’ll be exploring those options. 

Finally, we’ll be looking at some suspension options to augment out fairly worn-out stock suspension. Only a set of Koni strut inserts separate our MR2 from how the factory delivered it, and time has taken a toll. We’ll be doing some necessary maintenance and working on upgrading as we go.

In the meantime, enjoy a ride-along from our best run this past weekend, and enjoy those sweet turbo sounds and the fun mid-engine handling.

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Comments
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djsilver (Forum Supporter)
djsilver (Forum Supporter) Reader
9/19/20 4:02 p.m.

Great to see you at the FIRM and glad to hear you were able to overcome adversity and get some sorting-out done on the car.  The CFR/BUCC crowd at the FIRM is always stout.   There's another event there on October 3rd.  Hope you can join us again!

JG Pasterjak
JG Pasterjak Production/Art Director
9/21/20 10:45 p.m.
djsilver (Forum Supporter) said:

Great to see you at the FIRM and glad to hear you were able to overcome adversity and get some sorting-out done on the car.  The CFR/BUCC crowd at the FIRM is always stout.   There's another event there on October 3rd.  Hope you can join us again!

i'm a definite maybe for that one. I'm signed up for the Dixie event next Sunday, and I think I have a conflict on that first October weekend, which is why I took the event the week prior. If that conflict clears before registration closes, though, I'll likely head back to the FIRM as well.

300zxfreak
300zxfreak Reader
10/25/20 12:15 p.m.

I like the course, it looks like one that I might actually. navigate my way around without getting lost.

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