Quest For The Perfect Street/Track Suspension - Fun With AST's!

Since so many people, myself included, want the ultimate street/track coilover setup for their E46, RRT has set out to make one - and at an affordable price point.

This thread will document our development of the AST single adjustable kit from start to finish, using our suspension blueprinting technology.

Our goal: create a kit that is as good on the street as it is on the track - one that preserves good handling characteristics but is still truly streetable. The best way to do that is to customize - we have the ability to test, establish what is ideal on paper, and then change the internals of the shock until they match up.

The test mule: my 330 - street driven track day/driver school car, and future time trial ride (if anybody wants detailed specs ie: tires, camber, weight, etc. I will provide them throughout)

Where to start? We wanted to use quality components that are end-user friendly and won't break the bank, so we got our hands on the single adjustable kit from AST.

Like tuning your motor, tuning your suspension requires a baseline so the shocks went straight on our Roehrig shock dyno. In addition to analyzing the force graphs, we tested variables like changes in temperature and different gas pressures. I'll be explaining what that kind of data means over the course of the week. Here's an example of what the graphs look like:





Video:
http://www.rrtsuspension.com/videos/dyno.wmv

Next up - use string-pots and our Aimsport data acquisition system to measure and log the shock velocities while on the car, during a range of tests that represent different driving conditions.

More details and pics of the install tomorrow, and continuous updates to follow throughout the project.

Very cool. Subscribing.

This is downright cool...I can't wait to see what comes out of this...

The snow storm we're having right now put a wrench in our schedule. No point in putting the shock pots on until the weather is a little better. I'll keep you all updated!

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We are excited to be working with RRT and look forward to the ongoing development they have undertaken with several new AST products.

Originally Posted by Fair

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We are excited to be working with RRT and look forward to the ongoing development they have undertaken with several new AST products.

Good to see you on here

Originally Posted by shady3one3

Since so many people, myself included, want the ultimate street/track coilover setup for their E46, RRT has set out to make one - and at an affordable price point.

Ah, the Holy Grail of the financially challanged track enthusiast....like me. I'll definately be watching. Thanks for what will prove to be beneficial to a lot of us, regardless of how it turns out.

It's also cool to map out all of you pickup points, calculate your motion ratios, roll centers, centers of gravity, anti dive/squat, unsprung weight, sway bar spring rates and so on. Then see how your ride frequencies compare to what the shock pots give you. Then get a set of Koni's and spend twice as much as they are worth in making custom valving just so they are in the ballpark as compared to the Motons that are now just sitting in a box (actually spending tons of money is not the cool part).

Anyone interested in a used set of 3-way Motons that for an E46.....

Originally Posted by mrshelley

It's also cool to map out all of you pickup points, calculate your motion ratios, roll centers, centers of gravity, anti dive/squat, unsprung weight, sway bar spring rates and so on. Then see how your ride frequencies compare to what the shock pots give you. Then get a set of Koni's and spend twice as much as they are worth in making custom valving just so they are in the ballpark as compared to the Motons that are now just sitting in a box (actually spending tons of money is not the cool part).

Anyone interested in a used set of 3-way Motons that for an E46.....

If I were setting up a racecar I would get that detailed...but this is supposed to be fairly generic.

I've got a set of those motons in a box too if you want to start a collection

Interesting. Since I just put on a set of AST coilovers I'll be interested in following this thread.

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Mini update -

We've been hemorrhaging staff between the DC Auto Show (we have two cars on display) and Daytona this week, so no news on my setup.

We did however get a "clear" shock from AST USA (thnx Terry), and its pretty darn cool. You can see cavitation on paper all day long, but its another thing to physically see what happens when you change the gas pressure in a shock. Expect some pics of our experiments on monday.

Originally Posted by shady3one3

Mini update -

We've been hemorrhaging staff between the DC Auto Show (we have two cars on display) and Daytona this week, so no news on my setup.

We did however get a "clear" shock from AST USA (thnx Terry), and its pretty darn cool. You can see cavitation on paper all day long, but its another thing to physically see what happens when you change the gas pressure in a shock. Expect some pics of our experiments on monday.

Wait...you're at daytona this week? What race are you in, the Koni Challenge or the Rolex? I'll stop by and see you guys when I'm at the track...

We don't have a grand-am car this year, RRT is down there consulting with Koni Challenge teams.

There's already some good pics of the DC Auto Show here.

Originally Posted by shady3one3

We did however get a "clear" shock from AST USA (thnx Terry), and its pretty darn cool. You can see cavitation on paper all day long, but its another thing to physically see what happens when you change the gas pressure in a shock. Expect some pics of our experiments on monday.

Thank Hanchey for sending that. Just be careful running that plastic shock on the dyno... run the N2 pressure too high and cycle them too quickly and you'll make a mess.



Here's a video (linked above) of an AST4200 double on a dyno. We had this at the PRI show and everyone loved seeing how the pistons worked, the nitrogen chamber, etc. Its a great "show-and-tell piece" and we even had an instructor from a technical school ask us to build him one for use in his classes.

Actually, I think Brian said not to try it on the dyno at all...or at least that's what Barry is going with I'm not gonna lie, my favorite part of that thing is that the oil looks hot pink

For the local guys, said "clear" shock is over at the auto show with a set of e36 AST's. Come down and check it out, I'll be at our booth tonight after I'm done at the shop (7-10pm) and much of the day saturday and sunday.

Just look for these two cars by the autograph stage

Originally Posted by shady3one3

We don't have a grand-am car this year, RRT is down there consulting with Koni Challenge teams.

Nuts. Ohh well at least I get to see TMS...

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Any updates? I will be replacing the suspension on my E36 M3 soon so I am curious to hear your outcome -- I guess this data will translate well from E46 --> E36?

Also, are you going to do any dyno comparisons with the other coilover kits?

We are developing the E36 setup as well (and e90/2/3). In fact, Barry experimented with some customized bleed valves in them this week and got awesome results in terms of creating a true and consistent change in force for each turn. We've got the e36 double adjustable kit going on two race cars and already on an m coupe for One Lap of America. Working with AST right now on some further changes.

As for comparing other kits on the dyno - yes, we have tested every brand we can get our hands on, and are always amassing more data. I don't want to knock any specific brand or anything, but on paper, it looks like OEM M3 dampers will control a stiffer spring setup better than the lower end coilover kits. The lower quality dampers also seem to show a greater disparity in temperature tests, likely due to the characteristics of their oil.

Spending some time this week on non-suspension related issues with my car to create a clean slate for collecting shock pot data.

First off, great thread. Thanks for all thee info you are providing.

Second, how much dyno data do you have available on OEM dampers? I've been scratching my head for a while trying to interpolate what the Sachs "damping parameter" values really mean. Particularly interesting would be a comparison between the pre-01 sport dampers, the post-01 sport dampers, and the ZHP dampers.

Edit - FWIW, the damping parameter values are tabulated here - http://forum.e46fanatics.com/showthread.php?t=398977 - and I can also email the actual spreadsheet to anyone interested.