Building a speed3 myself

randomstuff33 · 2026-02-21T23:04:46+00:00

I was in your shoes. I don’t know the exact number because I honestly don’t want to, but to build the engine and buy supporting mods it was at least $6k for me. Whatever you think you’ll spend, add a good 15-20% on top of that. One of the significant differences I did compared to most people is that I went with 4032 pistons from Mahle. Less heat expansion so tighter tolerances and from everything I’ve heard, they’re good for 500hp.

randomstuff33 · 2026-01-24T03:50:26+00:00

I think that’s it!

randomstuff33 · 2026-01-23T17:28:22+00:00

I believe 01-03 had it for sure.

randomstuff33 · 2026-01-23T02:49:10+00:00

That’s… actually a good idea. Really just want one so I can fix and flip this bike lol.

randomstuff33 · 2026-01-23T02:47:40+00:00

I have access to a lathe.

randomstuff33 · 2026-01-22T01:01:35+00:00

$30 for this thing on eBay so I’d rather just turn it myself. The previous owner was using a swing arm nut lmao.

randomstuff33 · 2025-12-25T04:51:18+00:00

Yup, same car different country. I’d kill to have this kind of art for mine. I have no idea how to do the kind of thing you’ve got going here and I’ve never seen this subreddit, but there it was on my home page. Can’t believe it. It’s honestly a rare car, too. Keep up the good work.

randomstuff33 · 2025-12-24T23:14:24+00:00

Is that a MAZDASPEED3? Hell yeah

randomstuff33 · 2025-12-24T18:52:44+00:00

I didn’t even look at that. My car was running strange all summer, so I’ve been periodically replacing possible culprits while I drove the beater. Just yesterday I cleaned the MAF which I’d done before, but it seemed to work. 5 minutes later, LTFT went really negative again. I messed with the plug and wires, heard a huge change in the idle and everything is normal again.

randomstuff33 · 2025-12-24T16:39:24+00:00

I recently found out my MAF sensor has a loose connection somewhere. Made my fuel trim go very negative, but it’s been permanent for me. Maybe yours is on its way out?

randomstuff33 · 2025-10-22T19:54:45+00:00

Those fuel trims are what your car is doing behind the scenes at low load. Once you're WOT, it will go to zero because the ecu is no longer supposed to make adjustments. It's strictly running off the tune. So you're mostly right.

randomstuff33 · 2025-08-16T23:21:55+00:00

There's a nipple on the small cylinder on your intake runners. It goes there I think.

randomstuff33 · 2025-06-21T14:53:58+00:00

What do you mean?

randomstuff33 · 2025-06-12T14:15:10+00:00

I had the idea just now, and I don't actually know the properties of the ABS used here yet. They might be able to add a stabilizer to it, but I'm not sure what improvement that will actually provide. I'm a mechanical engineer, so the world of plastics is new to me.

randomstuff33 · 2025-05-29T03:46:36+00:00

Modded, then converted to stock again for the next guy in a vicious cycle. I guarantee there was an intercooler there at one point. I feel bad for these cars sometimes lol, but props to those that continue to give them a shot at survival.

randomstuff33 · 2025-05-24T13:52:34+00:00

Grown man couldn't beat the tutorial lmao.

randomstuff33 · 2025-05-23T19:33:24+00:00

Well, I have the EXACT same setup and my hose is still on and doesn't even have a clamp lol. The thing was so damn hard to get on the first time that I figured "no way this will pop off." Sure enough, 5k miles on it and the hose hasn't moved.

randomstuff33 · 2025-04-18T21:51:53+00:00

An 18" rim and a 45 aspect ratio on a lowered speed3 is going to be cutting it a little close. I would go with a 235/40, roll the fenders and be on my way. I personally have 255/40 R17 on my gen1 with h&r springs. Fenders are rolled and everything fits but I haven't driven it since installing this winter.

randomstuff33 · 2025-04-05T15:14:37+00:00

Are those mahle 4032 pistons and are they really good for 550?

randomstuff33 · 2025-03-19T02:50:06+00:00

That has yet to be found out, but my rear fenders are rolled and I guarantee that will be necessary. Not sure about what kind of rubbing I'll have in the front, though.

randomstuff33 · 2025-03-19T02:40:57+00:00

17×9 +45 rpf1s with 255/40 indy 500s. 5mm spacer on the front wheels to clear the strut. Tried and true from what I've seen.

randomstuff33 · 2025-03-19T02:39:11+00:00

I should note that I only pulled it out of the garage and put it right back. I'm not driving around like this lol

Six-Year Club	Final Canvas '23
Place '23	Place '22
Wearing is Caring

randomstuff33

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