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View Full Version : AST 4150 – Initial Impressions / Review



trustydrip
11-21-2013, 10:58 AM
Now that I’ve had these installed for a couple weeks I figured I would share my thoughts. This is my daily driver as well as autocrosser (monthly) and soon to be HPDE car. First off, the order process. I got these through Vorshlag, and even though there was a slight shipping mishap, they were an absolute pleasure to work with. They were also very helpful after the install verifying ride heights and alignment specs. I opted for all the goodies (spherical RSM, Vorshlag camber plates, etc), and went with 550F and 650R spring rates. Right now I’m running staggered Hankook RS3s and a UUC front bar, but no rear bar. I might look into getting an OEM rear bar for testing soon though. These dampers have tons of technology built in like digressive pistons and other stuff I don’t understand, so for a full list of features, check them out on Vorshlag’s page.
http://www.vorshlag.com/product_info.php?cPath=1_4_155&products_id=460

Drivability:
These are WAY more comfortable than my previous setup (Bilstein sport + H&R race springs). Yes, I know all about the race springs and how terrible they are, but I didn't expect such a significant improvement, especially with the relatively stiff spring rates I went with. While still communicative, I found the biggest improvement to be over large bumps, they are much less jarring now (not bottoming out). The car still sits low (~12.5” from center of wheel to top of arch) but without the Rieger lip I had before, I have yet to scrape on anything (Tempe can be a real sh*t hole sometimes too). On the street, the car kind of feels like my buddies 335i on springs, sporty and stiff, but far from uncomfortable. It’s a much more OEM sport feel. I love it.

Performance:
As far as performance, I am absolutely blown away. The car was aligned and corner balanced by Loud Pedal Motorsports (great shop to work with, I would recommend them to anyone in the area) last week, then autocrossed on Sunday at Wild Horse Pass or whatever (formerly Firebird). At the beginning of the day I set the dampers at 9 clicks from soft on the front and 7 clicks from soft at the rear. To be honest it was like driving a whole new car. With the old setup, the car would immediately understeer, and then I would control with the go pedal. Not any more… Even with the staggered tire setup (225F, 245R), understeer was almost completely eliminated. I didn't play around with the settings too much because I was struggling to catch up to the car, but when I did, the difference could be easily felt. The adjustment clicks are satisfying and make a discernible difference in the way the car handles. It’s almost telepathic now, and without the rear bar, I was able to put power down so much earlier. Next month, I’ll be playing around with stiffening the rear, as I prefer a car that's a little tail happy. Hopefully I won’t be completely overwhelmed by the new speed again…

4100 vs 4150
Now, I know some people had issues with the old design, but I think they have been addressed with this update. The sway bar bracket is now welded on, and there shouldn’t be issues with running the car at higher ride heights. That being said, I’ll update this thread with regards to reliability as I stack on the miles. Because in the end, it doesn't matter how well the car performs if the dampers go out after 5,000 miles.

Conclusion
All in all, I am really happy with this setup. Perfect comfort for daily duties (girlfriend approved), yet I can stiffen it up and battle boost buggies around the cones on Sundays. I can post some pictures up if people want, but they wont be very interesting.

ThreeD
11-21-2013, 11:51 AM
Awesome. I had the 4100 setup before and loved that setup, and had no issues with reliability through nearly 20,000 miles. It was harsher over large bumps than stock/my current TCK S/A setup, but it sounds like that's been worked out with the 4150s. I wouldn't mind giving the 4150s a try if I decide to ditch my TCKs for something better...

Looking forward to seeing the updates

trustydrip
11-21-2013, 01:22 PM
Yeah, I feel like the negative experiences with the 4100s were voiced quite a bit louder than the positive ones (which is usual for any product). That's why i decided to share my experience. I would love to drive a car on the TCKs or TRM coilovers and see if the extra price for the ASTs is worth it.

Eric98Sedan
11-21-2013, 01:28 PM
Sounds nice. I've always had a curiosity about the ASTs. Monotube, digressive valving.... very Bilstein-ish. Very good.

Probably too stiff for a cushy street ride, though, which is why I've never pulled the trigger on them.... but I would LOVE to try them.

camdinans3
11-21-2013, 01:37 PM
I've been pleased with my 4100's, aside from the swaybar tab ripping out and completely destroying an endlink (vorshlag replaced the tab for free but it was a pain removing it all just to replace it and i had to hound them and be pretty firm).I want to upgrade to the "new" design for the swaybar tab in billet but they are very expensive. Been driving on them for 4yrs now. maybe 15k (street/track/autox). Pretty good on everything other than the occasional expansion joint. I would love to have the internals rebuilt to 4150 spec. perhaps in the future.

ThreeD
11-21-2013, 05:09 PM
Yeah, I feel like the negative experiences with the 4100s were voiced quite a bit louder than the positive ones (which is usual for any product). That's why i decided to share my experience. I would love to drive a car on the TCKs or TRM coilovers and see if the extra price for the ASTs is worth it.

I can tell you with certainty that my ASTs performed better around the track/autocross than my TCKs. Chassis was more settled over bumps and adjustments were easier to make. Also better at absorbing smaller impacts. But worse at absorbing large impacts on the street like potholes.

propcar
11-21-2013, 07:44 PM
I can tell you with certainty that my ASTs performed better around the track/autocross than my TCKs. Chassis was more settled over bumps and adjustments were easier to make. Also better at absorbing smaller impacts. But worse at absorbing large impacts on the street like potholes.

similar rates?

OP: good review, those 4150's seem like a nice bit of kit.

ThreeD
11-21-2013, 09:43 PM
similar rates?

OP: good review, those 4150's seem like a nice bit of kit.

Same exact springs!

VaTechE36
11-22-2013, 09:57 PM
I've got some 4100s in a box awaiting a rebuild, but wasn't sure if I should go with upgrading them to the 4150 spec. Nice review though. I've driven the 4100s on track with 500/600 springs and really loved it, but now the debate might be back to do the "while you're in there" and update to 4150 specs.

Thanks for that lol...

modernbeat
11-23-2013, 10:47 AM
Andrew, I can highly recommend swapping to the double digressive pistons.

VaTechE36
11-24-2013, 07:15 PM
Jason, certainly a good idea, but I'm not sure I want to invest the money into them over just a regular rebuild. I'll keep thinking about it though!