MR2'sday!

"Nonster" (noahnic) 03/22/2016 at 11:30 • Filed to: None

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Autocross season is coming up fast so I’ve been scrambling to get the MR2 ready to go!

13's, 15's, a tailpipe, oh my!

Wheels & Tires!

The big question mark I still have left is my wheel and tire choice. I was trying to decide between 15x8's with 225/45-15 200 treadwear summer tires or a more dedicated set of track-only 13x8's with 225/45-13 R-comps. The 225/45-15 is a lot of tire to squeeze under the front fenders of a Mk1 so I went to try on a buddy’s set from his Mk3 Mr2. His little MR-S is undergoing a 2ZZ swap so now we’ll both be running in SSM!

mmmm so much meat....

They’re green! And they fit!......Almost. His RPF1's have a bit too little offset. Once I dial back in a few degrees a camber and if I rolled the fenders they might be okay, but my springs are still pretty soft so I get a good bit of body roll so they might rub.

Merry Christmas!

I really like the setup, but it would only be marginally faster than my old 15x7's with 205/50-15's. Because of that I’m leaning towards the 13's. The R-comps (still torn between pricey and fast Hoosiers or cheaper and slower R888's) will help a ton, but the other benefit of the 13's is the smaller diameter tire.

The 20v 4AGE is a very peaky, high revving motor. It makes good power, but only way up in the rev range so its an absolute dog if you don’t rev the nuts off it. Many times last year I found my self bogged down in the tight sections of the AutoX courses way out of the powerband. The reduced diameter will effectively provide a lower final drive ratio. Depending on the course layout I’ll probably have to shift into 3rd sometimes, but I think overall it’ll be faster.

Exhaust Repair!

The next issue to tackle was the exhaust. The cat-back/tailpipe is this ricey 5zigen setup I picked up for cheap when I did the engine swap. The original owner had wrapped the whole thing with that fiberglassy exhaust wrap stuff. It looked kinda neat, but it just held moisture against the pipe and a nice loud rust hole developed a few months ago.

So I cut off all that crap and was surprised to see that the only rust was on the U-bend near the hole. So I went to town grinding off all the rust off the pipe and prepping it to weld in a patch.

I then realized I was out of shielding gas for my welder and the welding supply place was closed on the weekends......well shit.

Screw it, flux-core wire will have to do. Usually my welder really likes to burn through exhaust tubing when I use flux-core wire so regular MIG-mode with solid wire is much preferred.

So the welds came out shitty since I had to move fast to prevent it from burning through, but its only a patch so it’ll get the job done for now.

Then I hit the whole thing with some flat-black, high-heat paint and BOOM! its good as new!

Test & Tune day is April 3rd with the first race a week after that. I really want stiffer springs or swaybars, but I only have room in the budget for wheels & tires right now. We’ll see how things go!

uofime-2 > Nonster 03/22/2016 at 11:52

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It should be pretty easy to run the numbers on new wheel and tire setups to compare how the change in circumference between different wheel and tire setups will effect your RPM at different speeds and gears

rockingthe2 > Nonster 03/22/2016 at 13:22

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I need to get my MR2 back so I can do MR2sday as well!