MR2- Rallycross suspension debate

So I've decided I'm probably at the point of diminishing returns on engine upgrades to the stock 4AGE. Open exhaust, K&N intake, good plugs and wires, dyno'd at 120HP. It was around 104HP if I remember before we started. From what I've read/been told on other threads, I could throw $1000 or more at it and get maybe 5-10HP if I'm lucky.

I've decided I'd rather go after what the car was really known for, handling! I'm pretty sure I'm running on 26 year old shocks/struts, and most certainly vintage rubber bushings. I've looked around a bit & have come up with this:

Prothane 18-2008 Red Total Kit Amazon (Comes with C-Arm Front And Rear/Steering Bushings/Strut Arm/Sway Bar Bushings)

Koni 8641-1142SPORT Yellow Adjustable Sport Shock and 8641-1071SPORT Yellow Adjustable Sport Shock
Amazon and Amazon

So it looks like ~$85 for the bushings, and ~$165 each for the shocks/struts. That's $660 + $85 in parts. I got quoted $675 for replacing the shocks/struts and 4wheel alignment. Somewhere north of $1400 real quick.

My question to the masses, are the Koni's worth it? Would I be just as/almost as well off going with cheaper like KYB? My driving skills are improving every event, but I get the idea that rallycross is not as dependent on super-tuned suspension like autocross would be. Am I correct?

I'll just mention that the poly bushings I have on the e30 rallycrosser squeak like CRAZY after one season. Can't grease them too much because that will just hold more dirt and grime.

I'm specifically referring to my rear LCA bushings, btw. I have some poly stuff in positions that move less (swaybar, steering rack, etc) and they seem to be fine.

I would say Konis will be worth it (the Bilsteins definitely were for the e30). But instead of worrying about more power, how about losing weight? Not sure how much your wheels weigh, but could go lighter there. Take the rocker sills/front lip off, etc etc...

In reply to irish44j:

Not worried about more power, I have as much as I believe I will have for the foreseeable future & a ride-along with a more experienced driver behind the wheel showed me it has potential as-is.

I'm looking to upgrade the suspension/handling, and mostly wondering if the generic KYB struts would work for me, at least vs 26 year old parts.

Konis are worth every penny on a MR2. MR2s are nervous on stiff compression struts, and really prefer a nice softer compression, higher rebound. The Konis are the best I've tried and the only strut (short of custom valved versions) that I would ever use on one again.

I've owned KYBs, Tokicos, etc., but it is worth all the plasma you have to get the Konis. Yes, they are that much better, especially for this car.

As for installation, it's pretty easy really. JG had a good article on it a while back. If you slot the bracket where the brake lines attach, you do not have to take the lines off the car. I could change all 4 in under two hours taking things slow. If you already had the brackets slotted, and you were in a big hurry, you might could do all 4 in 45 minutes or so using hand tools. Even the bushings are pretty easy. There aren't that many of them, but you will need a press for a few. I took all my pieces loose, and then took them to a friend with a press.

I think you have a good plan, but get the Konis.

As for weight, without metal cutting, it's never going to be really light. My ITA car weighted in at about 2,275 without a driver. I had a difficult time getting it to the 2,375 or whatever it was, with me in it.

Hoelscher's car I believe is less than 2,000, but there's a lot of it missing and it's built to the max rule set. How far do you want to go? If it's not a street car, removing the sound deadening from the interior I believe was 10lbs or so. Then there's any AC system equipment for a few pounds, the wing and ground affects for a couple of pounds, the spare tire and jack for maybe 5. A smaller battery will get you a few, and if you don't need the dash, there's another 10 pounds or so if you can also live without the fan and wiring. Now if you can do the glass, there's a bunch, and if you can replace body panels with aluminum, fiberglass or carbon fiber, you can take off a lot too.

You're hp is actually pretty good. My IT motor was slightly lower than that at the wheels, but Steve's motor is pretty far north of that the last time I talked to him. If you want to open it up and go inside, there's a lot of power, but it's not cheap.

Anyway, love your car and it really makes we want another one!

Best part about the Konis is that you can soften them up a little bit after you change tires and then tighten them back down for the drive home.

I had been running KYB GR2s all the way around on the neon ever since the infamous strut-out-the-side incident a couple years back and they weren't bad - especially for the money. I just blew one of the front ones at the Enduro Challenge, though, so I'm not sure what the longevity is like.

Jerry, You're on the right track going after handling rather than power. I was pleasantly surprised with the power and drive-ability of your car.

I've never owned koni dampers but I have heard/seen that they aren't suited for rallycross nearly as well as they are for street/autox use. I would probably put the $$ amount difference between fresh generic dampers and konis towards slightly stiffer springs.

Again, whenever you want to have a tire grooving session I can give you a run down on some specific suggestions. They'll basically boil down to: decent dampers, moderately stiff springs relative to stock, try disconnecting sway bars, and some driving technique tips.

I came in here to suggest Bilstein HDs since they're the Answer if you can get them for your car, but I'll defer to the people with MR2 experience who say the Konis are magic.

Regarding bushings... IMO stock rubber in good condition is better. Poly bushings allow the suspension to move better since the bushing material isn't bonded to anything, but the downside to that is the plastic will compress/deform over time and develop play. And that's why my car suffers from torque steer...

Maybe I'll look into Bilsteins today, I did some searchin' recently and only saw Koni's and KYB as a generic OEM-like replacement.

Jerry wrote: So I've decided I'm probably at the point of diminishing returns on engine upgrades to the stock 4AGE. Open exhaust, K&N intake, good plugs and wires, dyno'd at 120HP. It was around 104HP if I remember before we started. From what I've read/been told on other threads, I could throw $1000 or more at it and get maybe 5-10HP if I'm lucky.

That's not true, you have hit a new tier of expense but 4AGE power adders don't get really expensive until 160-170HP. You can still get cams & ITBs without spending huge money. The "$1000 might not even get you a 2-digit gain" point starts at 200hp.

I hope I get the same gains you did (CAI, cone filter, fully wrapped open exhaust, thinner HG).

Looks like Bilsteins are only available for the SW20. Shame since they are awesome.

Or you could get some $pendy custom Bil$teins along the lines of what this MR-2 has...

racerdave600 wrote: Now if you can do the glass, there's a bunch, and if you can replace body panels with aluminum, fiberglass or carbon fiber, you can take off a lot too. Anyway, love your car and it really makes we want another one!

I've debated taking the side windows and motors out, but like to drive the car occasionally in less than ideal weather. Plus I've seen some guys with window nets at dust bowl events and it looks like the interior is on fire.

In reply to Jerry:

Best suspension mod I've made on MR2s (I've raced MKI before and am racing a MKII now) was replacing the bushings (rubber/poly/delrin) at the front of the strut rods/trailing arms with spherical bearings.

Before that mod, had to step on the lower arms to remove the ball joint or the hub. After that mod, the arms fall from their own weight.

There are suspensions for sale with all spherical bearings, but changing those 4 was the best "bang for the bucks"

I'll say this, Koni yellows are the best OTS damper for the AW11 for almost every application. That said, I'm not a rallycrosser and I can't speak to how they perform there.

Definitely stay away from the Illuminas, as they have some pretty stiff rebound characteristics. Not that they're a bad damper per-se, but they seem ill suited to your endeavors.

KYB - dunno. I haven't heard that great of things about them. However, if rallycross needs a more OEM-like damping curve then they might be worth a try.

I've seen Illuminas self-destruct at rallycrosses in one event. Bent shafts, struts stuck at full droop. On the rear of a Storm.

So looks like Koni's it is. I could swear everyone else loves the Prothane bushings, from what I've read elsewhere. Big time increase in response?

Jerry wrote: In reply to irish44j: Not worried about more power, I have as much as I believe I will have for the foreseeable future & a ride-along with a more experienced driver behind the wheel showed me it has potential as-is. I'm looking to upgrade the suspension/handling, and mostly wondering if the generic KYB struts would work for me, at least vs 26 year old parts.

He said instead of POWER, what about losing WEIGHT from the car.

power isn't that hard... I've got 170hp(145 whp) on almost all stock parts The only aftermarket bits are cams, valve springs, wrist pins, and engine management... all the rest is stock Toyota. The key to a 4AGE is head work... easily 10+ hp in the head alone

z31maniac wrote: He said instead of POWER, what about losing WEIGHT from the car.

He said "But instead of worrying about more power, how about losing weight?", and I said I hadn't mentioned power, only handling. But I'm all about losing weight too. (Aren't we all?)

Jerry wrote:

z31maniac wrote: He said instead of POWER, what about losing WEIGHT from the car.

He said "But instead of worrying about more power, how about losing weight?", and I said I hadn't mentioned power, only handling. But I'm all about losing weight too. (Aren't we all?)

I was actually just reinforcing/agreeing with what you said in the first paragraph of your first post : "I could throw $1000 or more at it and get maybe 5-10HP if I'm lucky" and how you weren't interested in that.

I was suggesting the other non-suspension way to make the car faster without throwing $1000 at the car, since you don't want to do that. Do all the suspension you want, but in rallycross lightness is the ticket in my opinion. In almost every class of our local region the lightest cars tend to be the fastest, not the more powerful cars (exception: the H6-swapped Impreza wagon is very, very fast - but he also has 3 LSDs). On a car like the MR2, dropping 100-200lbs could make a big difference.

irish44j wrote:

Jerry wrote:

z31maniac wrote: He said instead of POWER, what about losing WEIGHT from the car.

He said "But instead of worrying about more power, how about losing weight?", and I said I hadn't mentioned power, only handling. But I'm all about losing weight too. (Aren't we all?)

I was actually just reinforcing/agreeing with what you said in the first paragraph of your first post : "I could throw $1000 or more at it and get maybe 5-10HP if I'm lucky" and how you weren't interested in that. I was suggesting the other non-suspension way to make the car faster without throwing $1000 at the car, since you don't want to do that. Do all the suspension you want, but in rallycross lightness is the ticket in my opinion. In almost every class of our local region the lightest cars tend to be the fastest, not the more powerful cars (exception: the H6-swapped Impreza wagon is very, very fast - but he also has 3 LSDs). On a car like the MR2, dropping 100-200lbs could make a big difference.

Well now that we have that straightened out...

Yup, I think I'm taking out the headliner this weekend (last remaining carpet), and see what other bits can be removed. Leaving the dash at least for now, I like the fan and gauges, and if I ever want to make it sort-of-OEM to resell.

Jerry wrote:

racerdave600 wrote: Now if you can do the glass, there's a bunch, and if you can replace body panels with aluminum, fiberglass or carbon fiber, you can take off a lot too. Anyway, love your car and it really makes we want another one!

I've debated taking the side windows and motors out, but like to drive the car occasionally in less than ideal weather. Plus I've seen some guys with window nets at dust bowl events and it looks like the interior is on fire.

Make lexan side windows?

irish44j wrote: Do all the suspension you want, but in rallycross lightness is the ticket in my opinion. In almost every class of our local region the lightest cars tend to be the fastest, not the more powerful cars (exception: the H6-swapped Impreza wagon is very, very fast - but he also has 3 LSDs). On a car like the MR2, dropping 100-200lbs could make a big difference.

Our regions have much rougher courses, so a little car weight isn't a bad thing to have. Keeps the ratio of sprung to unsprung weight favorable so the car stays gripping the ground. I've seen super-light cars run (Buggy Mod!) and they look like a serious handful to keep pointed in the right direction, what with how much they bounce all over the place. Random spins in unusual areas are the norm, and the times they put down are not competitive.

And power... power is always good to have. 230hp RWD is fun, I'm thinking of 500-600hp for the AWD car I'm (slowly) putting together. Because more power.

Jerry, you've already got a great car as it is. I'd just do maintenance to it and just drive the thing. The car i have is extensively modified, but most of that is a product of breaking things and re-engineering the car so it doersn't break there anymore. Until you get to that point (IF you get there), it's best to learn the car. Get Chris to co-drive with you more often, it's certainly been helping Evan along

In reply to Knurled:

Thanks! I still plan to do some suspension work, even on the street I can feel some uneasiness that this car should not have. But yes, more ride-alongs are in order. (And I have to say, I know most of the local guys here by their name, but do not recognize yours.......)