Vorshlag Motorsports Evo X MR Build (STU, TTB, One Lap?)
Feb 20, 2009, 12:59 PM
#64
Former Sponsor
Join Date: Aug 2008
Location: Dallas, TX
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Ask, and ye shall receive: new AST 5200 pics: http://vorshlag.smugmug.com/gallery/...77362366_FTxsj
More soon...
Last edited by Fair; Feb 20, 2009 at 03:12 PM.
Mar 4, 2009, 10:56 AM
#66
Former Sponsor
Thread Starter
Join Date: Aug 2005
Location: Parker, TX
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
The Vorshlag Crew had a fun filled track test day on Tuesday. A magazine we work with was in the Austin area working on a Tech article, so we had asked them to drive the Vorshlag EVO X for a possible future article. They finished up their testing on time and had Tuesday morning free. Our good friend, Andy Hollis, is a member at the new Harris Hill Road country club track in San Marcos. We had a magazine writer, a track, and a car. Road trip!
Left: The magazine tester talks with Andy. Right: Heading out on course
Seeing as the EVO build is supposed to be a "do-it-all" project, we decided to make the 251 mile drive down there in the EVO versus trailering it down there. We've had the Dunlop Star Specs on it for a while - they are doing fine and wearing well, with several track days, many autocrosses, and 6000 street miles. They are a great tire if you want to "do it all".
We left Dallas at 5:30AM, arrived 5 minutes late in San Marcos at 10:05, unloaded the car and got started. The EVO's onboard GPS Navigation led us directly there (for once). We had added Cobb sway bars to the car last week and had not tested with them on yet. Also, we didn't have time to set the camber trackside for the initial drive by the magazine writer, as his schedule was pretty tight. It wasn't really crucial since this was just a brief test drive. We weren't trying to set fastest lap (yet) - more on that in a bit. After a brief photo shoot, airing up the tires and removing our wares from the car, we were off. The car was a little pushy for our liking, but there wasn't time to really dial the car in for him.
The Harris Hill Road course has excellent pavement, big elevation changes, and lots of room
Everything went well and the comments were positive concerning the ride quality and handling. Keep in mind it has to be daily driven, autocrossed, and track driven which is a challenge in the EVO. We were a little disappointed that the car didn't handle up to our track standards out of the box, although it wasn't a surprise. We had not had the chance to get on the track since getting the AST 4200 suspension installed plus the new Cobb bars. We had autocrossed it with the ASTs, but that is a complete different driving style and camber/shock setup. After the magazine writer had left we put in several additional sessions in the EVO, playing with camber & toe, shock settings, tire pressures and sway bar settings. We were able to get most of the push out and the car was extremely neutral when the tires were cool. In a few laps the weight of the EVO just overpowered the narrow 245mm tires. We know it would improve considerably with 275mm rubber. When the tires overheated it would push, and the DL-1 data showed it in lap times. It would slow down a second or more after the first few laps. We saw as high as 1.21g lateral and 1.12g under braking, however, even with the skinny tires.
These pictures were with the "street" camber of -2°. It got a lot faster at -4°
Thanks to Chris Fleming at Cobb Tuning of Plano, who helped source new Hawk DTC-70 brake pads for the track testing and helped with the swaybar install at their shop. With these new pads braking on track was MUCH improved. Even though you're not supposed to drive them on the street, we took the car down there with the track pads on it. We just made sure our stops were all hard and fast on the highway, hehe.
The horses in the background liked the EVO's exhaust note
You can see in the pictures the car still has some body roll. We plan to go up in spring rates to help combat this. It rides so well now that I'm confident we can revalve the shocks, go up in spring rate, and still maintain good ride quality. We asked the track management what a good time at Harris Hill was for their clockwise 1.8 mile course. They said in a street car a 1:35 is fast, anything 1:30 or less is really fast. By the end of the day we were running 1:30 laps according to our data logger. We were happy with the results and know there's more time in it, especially with properly sized track wheels/tires. We'll be running it at a NASA Time Trial event in two weeks and a BMW Club event after that, so we'll make some tweaks and go back for more. Stay tuned!
Fair in the Miata: "Its a bit different than driving our V8 powered BMW..."
As a nice bonus, H2R let Terry drive their club's track prepped Miata (NB). It was equipped one of our competitor's coilovers on it so it was nice to get an on-track comparison. He was "just going to do a lap or two" on the almost corded race tires, but had a blast and stayed out lap after lap. Of course he said it needed better shocks, ha. Driving the lightened Miata on 225mm R compounds is "too easy", yet still lots of fun.
The folks at Harris Hill were great and they have a fantastic Country Club road course and driver's facility. If anyone that lives near Austin or San Marcos hasn't been out there they need to look for a DE event there and go (and join - we were there on an open "member day" and had the place completely to ourselves!) We're thinking of renting the track in the future and coming down again to test with some AST customers - it was well worth the 3.5 hour drive from Dallas.
Left: The magazine tester talks with Andy. Right: Heading out on course
Seeing as the EVO build is supposed to be a "do-it-all" project, we decided to make the 251 mile drive down there in the EVO versus trailering it down there. We've had the Dunlop Star Specs on it for a while - they are doing fine and wearing well, with several track days, many autocrosses, and 6000 street miles. They are a great tire if you want to "do it all".
We left Dallas at 5:30AM, arrived 5 minutes late in San Marcos at 10:05, unloaded the car and got started. The EVO's onboard GPS Navigation led us directly there (for once). We had added Cobb sway bars to the car last week and had not tested with them on yet. Also, we didn't have time to set the camber trackside for the initial drive by the magazine writer, as his schedule was pretty tight. It wasn't really crucial since this was just a brief test drive. We weren't trying to set fastest lap (yet) - more on that in a bit. After a brief photo shoot, airing up the tires and removing our wares from the car, we were off. The car was a little pushy for our liking, but there wasn't time to really dial the car in for him.
The Harris Hill Road course has excellent pavement, big elevation changes, and lots of room
Everything went well and the comments were positive concerning the ride quality and handling. Keep in mind it has to be daily driven, autocrossed, and track driven which is a challenge in the EVO. We were a little disappointed that the car didn't handle up to our track standards out of the box, although it wasn't a surprise. We had not had the chance to get on the track since getting the AST 4200 suspension installed plus the new Cobb bars. We had autocrossed it with the ASTs, but that is a complete different driving style and camber/shock setup. After the magazine writer had left we put in several additional sessions in the EVO, playing with camber & toe, shock settings, tire pressures and sway bar settings. We were able to get most of the push out and the car was extremely neutral when the tires were cool. In a few laps the weight of the EVO just overpowered the narrow 245mm tires. We know it would improve considerably with 275mm rubber. When the tires overheated it would push, and the DL-1 data showed it in lap times. It would slow down a second or more after the first few laps. We saw as high as 1.21g lateral and 1.12g under braking, however, even with the skinny tires.
These pictures were with the "street" camber of -2°. It got a lot faster at -4°
Thanks to Chris Fleming at Cobb Tuning of Plano, who helped source new Hawk DTC-70 brake pads for the track testing and helped with the swaybar install at their shop. With these new pads braking on track was MUCH improved. Even though you're not supposed to drive them on the street, we took the car down there with the track pads on it. We just made sure our stops were all hard and fast on the highway, hehe.
The horses in the background liked the EVO's exhaust note
You can see in the pictures the car still has some body roll. We plan to go up in spring rates to help combat this. It rides so well now that I'm confident we can revalve the shocks, go up in spring rate, and still maintain good ride quality. We asked the track management what a good time at Harris Hill was for their clockwise 1.8 mile course. They said in a street car a 1:35 is fast, anything 1:30 or less is really fast. By the end of the day we were running 1:30 laps according to our data logger. We were happy with the results and know there's more time in it, especially with properly sized track wheels/tires. We'll be running it at a NASA Time Trial event in two weeks and a BMW Club event after that, so we'll make some tweaks and go back for more. Stay tuned!
Fair in the Miata: "Its a bit different than driving our V8 powered BMW..."
As a nice bonus, H2R let Terry drive their club's track prepped Miata (NB). It was equipped one of our competitor's coilovers on it so it was nice to get an on-track comparison. He was "just going to do a lap or two" on the almost corded race tires, but had a blast and stayed out lap after lap. Of course he said it needed better shocks, ha. Driving the lightened Miata on 225mm R compounds is "too easy", yet still lots of fun.
The folks at Harris Hill were great and they have a fantastic Country Club road course and driver's facility. If anyone that lives near Austin or San Marcos hasn't been out there they need to look for a DE event there and go (and join - we were there on an open "member day" and had the place completely to ourselves!) We're thinking of renting the track in the future and coming down again to test with some AST customers - it was well worth the 3.5 hour drive from Dallas.
Last edited by hancheyb; Mar 4, 2009 at 11:40 AM.
Mar 4, 2009, 11:07 AM
#67
To follow up, in May, we're planning an Evo gathering, with the Friday afternoon being a track day at HHR. Come on out and play 
Details here: https://www.evolutionm.net/forums/so...e-invited.html
Details here: https://www.evolutionm.net/forums/so...e-invited.html
Mar 5, 2009, 08:29 AM
#68
Ask, and ye shall receive: new AST 5200 pics: http://vorshlag.smugmug.com/gallery/...77362366_FTxsj
More soon...
More soon...
Mar 6, 2009, 11:23 AM
#70
Former Sponsor
Thread Starter
Join Date: Aug 2005
Location: Parker, TX
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
Last night we were doing some "clean up" projects. I had a chance to throw the stock MR front strut on the shock dyno. Pretty interesting plot really. I did a run at 15 inches/second. This is a common "full sweep" people tend to want to see. It actually is completely unrealistic in the real world. There's no such thing as 15 ips in rebound so why measure it?
So I did a sweep at 5 ips as well. Notice how different the plot is on rebound (the negative side). Very little hysteresis and more progression AND zero or very little rebound at slow velocities. That's where you need rebound on turn-in. This curve has almost the opposite shape of all high end shocks out there where you have high rebound forces at very slow speeds and a digressive shape to the curve above 5 ips. 5 ips (or less) is more realistic as to what you see on the track or street and where you should look for performance. We've tested some of the low cost overseas coilovers where they made zero rebound force till 4 ips. That's the difference with high end shocks. Bistein makes good shocks and probably gets stuck with specs the manufacturer wants to meet liability and other requirements.
We recently purchased a potentiometer for testing (shock pot) to prove this in a real world situation by using our data logger and driving around on our test loop. We've got some really good pot holes, washboard bumps, and turns to show what your car is really doing on the street.
So I did a sweep at 5 ips as well. Notice how different the plot is on rebound (the negative side). Very little hysteresis and more progression AND zero or very little rebound at slow velocities. That's where you need rebound on turn-in. This curve has almost the opposite shape of all high end shocks out there where you have high rebound forces at very slow speeds and a digressive shape to the curve above 5 ips. 5 ips (or less) is more realistic as to what you see on the track or street and where you should look for performance. We've tested some of the low cost overseas coilovers where they made zero rebound force till 4 ips. That's the difference with high end shocks. Bistein makes good shocks and probably gets stuck with specs the manufacturer wants to meet liability and other requirements.
We recently purchased a potentiometer for testing (shock pot) to prove this in a real world situation by using our data logger and driving around on our test loop. We've got some really good pot holes, washboard bumps, and turns to show what your car is really doing on the street.
Mar 6, 2009, 12:42 PM
#72
Evolved Member
iTrader: (4)
Join Date: Sep 2005
Location: on the edge of sanity
Posts: 794
Likes: 0
Received 0 Likes
on
0 Posts
Brian,
Thats some good info there, I am very suprised to see how little rebound the stock shocks have below 3 ips. I wonder what the non MR shocks are like? Once I get my set on the car, I can send you a front evo 9 shock to test if you like.
Ryan
Thats some good info there, I am very suprised to see how little rebound the stock shocks have below 3 ips. I wonder what the non MR shocks are like? Once I get my set on the car, I can send you a front evo 9 shock to test if you like.
Ryan
Mar 6, 2009, 10:20 PM
#73
Mar 7, 2009, 10:12 AM
#74
Evolved Member
iTrader: (4)
Join Date: Sep 2005
Location: on the edge of sanity
Posts: 794
Likes: 0
Received 0 Likes
on
0 Posts
They didnt make a mistake, they are for an Evo 5. Which has the same suspension as a 7/8/9 (minus one mount). Those are 5200's for the 5, Brian is, I believe, running 4200's.
Those are 5200's for the 5, Brian is, I believe, running 4200's.
Last edited by RaNGVR-4; Mar 7, 2009 at 10:46 AM.
Mar 7, 2009, 02:20 PM
#75
Former Sponsor
Join Date: Aug 2008
Location: Dallas, TX
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Yes, I know it is. I was pointing out their mistake (I believe it is a typo. The V is so old at this point and never released in the States) listing their new offering as a Evo V coilover. I think they meant to list it as a Evo X coilover that will be released shortly and am anxious to purchase one.
AST has been making shocks for these cars for a while, but this is our first 5200 variation for a V. We are running 4200s on our X for now but have some 5300s coming for it soon. Confused on the AST models? Read this page: http://www.vorshlag.com/ast_models.php