Project Gen 3 STi Subaru GR M7 coilover SCCA autocross Milwaukee region

Project Gen3 STi GR suspension M7 coilovers SUbaru

Project Gen 3 STi: Suspension upgrade with M7

by Wes Dumalski

When last we left off with Project Gen 3 STi we were enjoying the power and up to this point the only modifications we had done so far were to make the car go faster. It's was time to change that as the GR STi is a bit soft around the middle. Our friends at M7 came to our rescue with their Super Street Performance Coilover setup. 

We were eager to put this new suspension through its paces to see what type of performance it really offered. The M7 coil overs have a retail price of just $1,595 making them quite affordable and us slightly skeptical. We knew going in that the real answers would come with time spent with the suspension and as such we offer this disclaimer. This review will be ongoing. One cannot simply bolt on a suspension and comment on ALL of its attributes or deficiencies in a single weekend. This certainly is a dual purpose suspension that will see the street as well as track and autocross time and as such we want to comment on our experiences as our build progresses. With that out of the way let's talk about what we noticed upon receipt!

While out covering the Modified Streetcar Shootout I came home to find a large parcel clogging up my hallway. While out of town my family members who were kind enough to care for my cats were also kind enough to move the M7 box in to my house. I mention this because if it were not for them we very well might not be reviewing this suspension right now and you very well may have bought it off of the electronic Bay for pennies on the dollar. Thanks to their assistance I quickly dropped my bags on the floor and wasted no time in opening the box. 

The first thing I looked at was the packaging and how it protected the product. M7 used double boxes and individual bags of packing peanuts to protect all 4 coil over assemblies. As I pulled out all 4 and unwrapped them I also found the tool bag inside. The kit comes with two spanner wrenches for perch adjustment as well as the proper allen head for the camber plate bolts. As I set up my station for a photo shoot with the M7 goodies I took in their fit and finish as well as design features. Frankly for their modest price point they have no business being this nice right out of the box. The anodizing on the top hats and perches is perfect as is the coating on the damper bodies. The adjustment knobs are knurled for easy adjustment and etched with arrows and the M7 logo. All of these nice little details make for a good initial impression.

M7 coilovers Subaru STi Gen 3 GR
The knurls on the adjustment knobs make for easy changes even with wet or slippery hands in the pits. The S and H marks along with the arrows make them virtually idiot (Wes) proof. 

I turned my attention to the front setup first and deduced what I could. The adjustment knob is on the top of the damper shaft and is labeled as a 35 way single adjustable damper. They use an adjustable camber plate that has reference markings on top and a sealed bearing design on the bottom. As you move down the damper you will notice the dust boot assembly as well as the plastic sleeve on the spring perch that isolates the spring from metal to metal contact.

M7 coilover camber plate sealed bearing subaru STi
Here you can see the sealed bearing design under the top hat as well as the spring isolators and dust boots. This setup comes fully assembled and ready to go out of the box. They also label the Left and Right side for ease of installation. 

The dampers use threaded bodies that screw in to the bottom housing and these housings have the tabs that mount to the control arm. They also have the appropriate mounting provisions for the ABS sensor as well as the brake line fitting. They use 2 collars in a jam nut configuration to secure the perch and adjust spring pre-load while a third collar on the bottom holds the damper within the bottom housing.

M7 coilover spring perch body jam nut STi suspension damper
Here you can see all 3 jam nuts that are turned with the included spanner wrenches. The lower nut unscrews to allow the body to thread in or out of the lower housing. This allows ride height adjustment without affecting spring pre-load. The upper perches adjust spring load. Our observations lead us to believe this is a monotube design with a single adjustment that controls mostly rebound with some compression. Unless we have the occasion to disassemble them or get them on a shock dyno our speculations will remain exactly that.

The front springs are labeled with the numbers 62 200 008. These numbers tell us the spring diameter and length in mm as well as the spring rate and in this case we have a spring that is 62 mm in diameter, 200mm long, with an 8kg/mm spring rate. If you convert that to standard measurements they are 2.5" diameter springs, 8" in length, with a rate of 448 lbs/in. For those of you who are curious you can convert kg/mm with the following formula: 

Formula = 1kg/mm = 55.9974146

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Wednesday, June 12, 2013 4:25 AM
Based on the design/construction details, I think those coilovers are made by BC Racing in Taiwan.

I'm no suspension expert, but I have experience with BC Racing on several Evos and have been pleased with how they ride and handle.

I would love to see someone like Mike test them and give us his point of view.
Wes Dumalski
Wes Dumalskilink
Wednesday, June 12, 2013 8:29 AM

There are similarities in production to some of the BC pieces. What I see as similar are the bottom housings and some of the top hat pieces. Without taking the damper apart (which we are not doing just yet) it is really impossible to tell how they are valved in comparison to a BC etc...

Mike and I did discuss this test and we chose to make this a living breathing review that is on-going. At some stage we may take these apart and explore valving but until then we wanted to offer what we have seen so far.
Wednesday, June 12, 2013 9:02 AM
That would be great if you could put them on a shock dyno as well as dismantle and inspect them.
Wes Dumalski
Wes Dumalskilink
Wednesday, June 12, 2013 9:07 AM
That has been discussed. That said I am sure you can understand our need to review them as is versus tearing apart a brand new set of coilovers?

Out of the box they are pretty darn good considering their price!
Andrew Saw
Andrew Sawlink
Wednesday, June 12, 2013 3:12 PM
I would agree these look similar to the BC Racing dampers. However there might be a difference in the internals as BCs are typically 32 clicks for the combined (compression and rebound) damping but the M7 is 35 clicks.
Wes Dumalski
Wes Dumalskilink
Wednesday, June 12, 2013 3:45 PM
I agree Andrew. At first glance it is easy for all of us to say "hey they LOOK just like BC or other companies" but the reality is that they could be built by the same manufacturer to M7's specs.

I do like the fact that they run the same spring rate front and rear and am looking forward to our next upgrade on the suspension which is front and rear sway bars along with some other driveline modifications to aid in driver feel.

We also are delving in to the fuel and other systems in our quest for more power.
Wednesday, June 12, 2013 5:13 PM
Don't get me wrong. I wasn't trying to disparage these coilovers by saying they look like BC made them.

And no, I wouldn't expect you to dismantle a new set of coilovers. It would be cool if you did though :)
Wes Dumalski
Wes Dumalskilink
Wednesday, June 12, 2013 5:19 PM
Not taken that way at all wrecked! It DID take every ounce of restraint to not take them apart though. I was trying to find a local shock dyno. but we decided to put them on and save that for a later time.

I expected a bit more flack based on the subjective nature under which we provided impressions; I tried to put the best example up that this would be an ongoing review.
Wednesday, June 12, 2013 8:04 PM
Wes Dumalski, great feedback, glad motoiq had the opportunity to get their hands on such a coilover set up. It is difficult to find solid information about M7 and especially this particular set up on any vehicle that is out in the market.
Friday, June 21, 2013 5:21 PM
Suspension is so difficult to judge, the damper is absolutely critical to the whole ride/handling compromise but it's a black box, you are down to looking at how well something appears to be made and subjective evaluation. How many people buy every option out there and compare them.

The problem is so far there are only a handful of quality damper mfrs in the world. M7 or BC ain't one of them. Making a proper adjustable damper with accurate and meaningful adjustments is expensive. Dyno's of off brand coilovers have invariably shown inconsistent plots, you can't even get 4 shocks of the same valving at each "click" much less a set of shocks a chassis engineer dialed in the valving on. Most of the shocks are generic with a clevis welded on for each application. I roll my eyes at "35 clicks" of adjustment. Do the M7 coilovers adjust rebound, compression or both?

There are a few options for the GR if you want world class dampers, Koni, Bilstein, KW, or AST. If I was only buying one set, and I wasn't doing reviews for a website, I would stick with those.

It is great to see tests of these off brands though, eventually some maker is going to get the combination of model specific tuning and damper quality right at a great price, BC is getting close. Would be cool if you get to dyno these to see if the shock is worth a damn.
Sunday, June 23, 2013 2:20 PM
I can agree with you “Power6”, yes there are many others manufactures that build and design way better suspension components but all of that comes at a price. For what M7 is and what they are trying to do, especially for the price, they are not bad at all, that totally in my opinion, plus I have seen few guys do pretty good on the redline time attack with this particular setup. There are many cheap coilover setups that should not be in the market but money and politics are involve, as long as forums such as MOTOIQ keep reviewing and giving honest opinion on what is out there in the market then we as consumers and enthusiasts should get a better grasp on what’s good and bad.
Wes Dumalski
Wes Dumalskilink
Monday, June 24, 2013 11:09 AM
#Power 6
Sure thee are the tried and true "world class" damper options that you mention however at time syou have to step outside of the box and see what the other offerings are made of. We catch a lot of criticism because we use KW on so many of our projects and that is a tough pill to swallow. We use them a lot because they WORK and WORK AMAZINGLY WELL. So when we decide to switch it up and provide our impressions on the M7 it is also tough to hear criticism that they are "not as good as" the dampers you mentioned.

Consider the price point and what you are getting here. This is an on-going review of this setup and we will spend more time to offer MORE findings. At some point they will likely hit the dyno. and we may take a peak inside and at that time we can expound further. Until then we can only offer our observations in actually USING the suspension ON the project car in different venue's.
Friday, November 07, 2014 8:24 AM
Anymore updates on this particular set up?
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