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E30 M50 tear down kinda thing


StewCrew

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10K front, 12k rear? Should be the otherway around. higher spring rates in the front, lower rear. Unless stuff is Different in Subaru WRX STi's. But I doubt that.

I've been doing a ton of research on this for e30's and for some reasons all of them have lower spring rates in the front. Do not know why.

My springs are 315 lb/in front 570 lb/in rear. The rear springs are stiffer because of the leverage involved in the trailing arm rear suspension design. If you go to a coilover design that relocates the spring onto the damper, then you need to reduce the rear spring rate to achieve the same balance (without doing the calculations I would estimate that I would need to go down to a 380-410 lb/in rear spring for example)

A 240sx for example, typically has equal or stiffer front springs than the rear (if my memory serves me properly this morning) due to it having a multi-link rear suspension where there is little to no leverage in the suspension links that would require stiffer springs than normal.

Edited by Snap Understeer
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10K front, 12k rear? Should be the otherway around. higher spring rates in the front, lower rear. Unless stuff is Different in Subaru WRX STi's. But I doubt that.

Idunno subaru motors work sideways so who knows. The BC's come stiffer in the rear, and for the most part I thought most coilovers come stiffer in the rear? But I wanted the car to feel super tight so I got higher rates, and it definitely does.

If this thing isn't on the fucking GROUND when I see it. I'll be dissapointed in you Jake.

If these "m50 into e30 chasis" mounts let the motor sit ever so slightly higher, then yes, shit will be dropped. If they dont, shit will also be dropped.
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Idunno subaru motors work sideways so who knows. The BC's come stiffer in the rear, and for the most part I thought most coilovers come stiffer in the rear? But I wanted the car to feel super tight so I got higher rates, and it definitely does.

Idk man, S13 coils are the same way, stiffer front slightly lesss stiff in the rear. I'd assume due to fat ass engines. But hey, potato.

If these "m50 into e30 chasis" mounts let the motor sit ever so slightly higher, then yes, shit will be dropped. If they dont, shit will also be dropped.

Dropped or dropped. I like it. Me too. I bottom out everywhere (my oil pan and new bumper) So I'm right along with you babe!

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Jake, what tire and rim setup are you using by the way? I'm thinking about doing a 15x8. I can have some decent grip and also a bit more tire to keep it cheaper. Also, are you okay with all this thread derailing? Haha

Thread derailing? Not giving a fuck man :) Im hopefully helpin you out with your future setup so its all good.

The sportmaxx in the pic I just uploaded were 15x8 on a 195/45 tire I believe? The car was scrapping everywhere. It was great. But I sold those and now have these:

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These are 17x7 with 20mm spacer up front (205/45) and 17x9 with 5mm spacers in back (215/45). Goodyear Eagle GT's all around. These are for cruising/meets/not drift day.

I just run all spares for drift days.

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\m/

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My springs are 315 lb/in front 570 lb/in rear. The rear springs are stiffer because of the leverage involved in the trailing arm rear suspension design. If you go to a coilover design that relocates the spring onto the damper, then you need to reduce the rear spring rate to achieve the same balance (without doing the calculations I would estimate that I would need to go down to a 380-410 lb/in rear spring for example)

A 240sx for example, typically has equal or stiffer front springs than the rear (if my memory serves me properly this morning) due to it having a multi-link rear suspension where there is little to no leverage in the suspension links that would require stiffer springs than normal.

The ways of the e30 explained. This is good info! Thanks :)

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I might step it up to a 16, but I feel like keeping them smaller would be lots cheaper for tires, and when you drift, you definitely use tires.

Just an FYI, if you're going to drift, go to a junkyard like gibsons in neenah, buy their shitty used tires, for $10 a pop. or buy new starfires. Those will last you plenty of drift days. Starfires last for eva

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XXR and ESM seem to be the best style+fitment per dollar wheels you can get new.

I still need to sit down sometime and figure out the best size of wheel + tire that allows for best tire availability and cost/performance ratio for track tires. I will probably do something close to 16x8 or 17x8 with summer tires for daily use. Either way, the wheels need to be light and strong. The Kosei K1 and TRM C1 wheels seem to be budget lightweight track wheel if light weight is important to you.

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