Anybody replace D-Specs with Bilstein HDs?

explrsport · Jul 17, 2009

I know a lot of guys in this forum run Tokico D-Specs and luv 'em - well, it hasn't been much of an affair so far for me.

I have a '05 GT Vert with 9k miles on it - not exactly a DD. Steeda 18" wheels, Steeda Sport Springs, GY GS-D3 275x40s all around at 28 lbs. Alignment and balance seem fine. BMR adjustable Panhard bar as well.

The D-Specs have 6k miles on them...no matter what setting I crank in, the ride seems too harsh. Not nearly as good a ride as I had on my lowered '02 GT Vert with a set of Bilstein HDs (the set that came with springs).

So I'm thinking of swapping the shocks/struts for the Bilsteins...anybody done the same or have any comments how I can co-exist with the D-Specs better?

GreyDiesel · Jul 17, 2009

Well, I dont run D-specs, but I have been doing a LOT of research on suspension. From other sites, I have gathered that D-specs are do have their detractors.

I hope I wont get flamed for saying that.

That is in regard to shock lifespan though, not actual ride quality. The sentiment seems to be that Bilsteins or Konis should last longer as they dissapate heat better. I am tempted to go with Koni's, just to support them for sponsoring the Koni challenge. But, I'll probably go with one full set-up from one racing team, like Roush or Steeda or FRPP.

I think the OEM shocks that come on the GT are manufactured by Tokico for Ford. In which case, the FRPP handling pack may also contain Tokico shocks. Of course, these are not D-specs, because they are not adjustable.

The main problem may actually be your springs. The Steeda springs are geared more toward track days. They have a linear spring rate. The best ride quality (while still having a lowered stance) will come from a spring with a progressive rate. I think Eibach, H&R, and FRPP offer progressive rate springs. (The FRPP are actually Eibach springs, though made to Ford specs). Roush may also offer a progressive rate spring, I am not sure.

In any case, I have come accross other posting of people with Steeda springs exeriencing a harsh ride.

FWIW.

I am no expert, so this is all just what I have gathered from other forums in the past month or so doing research on a possible suspension upgrade.

explrsport · Jul 17, 2009

Grey,

You might be right; like you, I'm certainly no expert and it might be springs not the shocks/struts. But I will note that Steeda's description for their Sport Springs certainly doesn't indicate they are meant for track use -

"Steeda Sport Springs - Part Numbers: 555-8216
Lowers the vehicle approx 1 inch front, 1 1/4 inch rear. The S197 Mustang sits high in the rear, these springs will give it a more aggressive look. Maintains good ride quality for daily driving. Big improvement in handling and noticeable reduction in nosedive."

I did have a chance some months back to drive a REAL track-prepared Stang with a full Griggs suspension - on the street - now THAT was really a harsh ride! But the owner got what he wanted and what he paid for.

GreyDiesel · Jul 17, 2009

agreed. I did not mean to imply they were only for track use. Just that, in comparison to Eibach, the Steeda's might be more performance oriented, and a bit more bumpy. I do like the look of the Steeda's more than any other spring.

Its too bad you cant try all this stuff out before you buy...

Steel Horse · Jul 17, 2009

explrsport said:
Grey,

You might be right; like you, I'm certainly no expert and it might be springs not the shocks/struts. But I will note that Steeda's description for their Sport Springs certainly doesn't indicate they are meant for track use -

"Steeda Sport Springs - Part Numbers: 555-8216
Lowers the vehicle approx 1 inch front, 1 1/4 inch rear. The S197 Mustang sits high in the rear, these springs will give it a more aggressive look. Maintains good ride quality for daily driving. Big improvement in handling and noticeable reduction in nosedive."

I did have a chance some months back to drive a REAL track-prepared Stang with a full Griggs suspension - on the street - now THAT was really a harsh ride! But the owner got what he wanted and what he paid for.

That right there tells me it probably has a higher spring rate that stock.

lightblade · Jul 21, 2009

Get the bilsteins! I have them and love them nice firm sportier ride but def not harsh. I had tokico illuminas on mt 01 GT and the 01 rode way harsher, hope this helps, I have bilstein hd's and ford racing k-springs.

lightblade · Jul 21, 2009

Also with lowering springs u might want to check your axle bump stops as sometimes they need to be trimmed and can make your ride feel alot rougher heres a link about it:
Lowering Springs & Bump Stop Modifications - ModularFords.com

explrsport · Jul 21, 2009

Good info! I just checked and the space between the top of the bumper stop dome and the bracket where it hits is between 3/8" and 1/2" (with no load on the suspension). I'll try cutting off the top section dome and see if that changes the ride any.

lightblade · Jul 23, 2009

Yeah thats what i did worked like a charm

walter · Jul 23, 2009

GreyDiesel said:
Well, I dont run D-specs, but I have been doing a LOT of research on suspension. From other sites, I have gathered that D-specs are do have their detractors.

I hope I wont get flamed for saying that.

That is in regard to shock lifespan though, not actual ride quality. The sentiment seems to be that Bilsteins or Konis should last longer as they dissapate heat better. I am tempted to go with Koni's, just to support them for sponsoring the Koni challenge. But, I'll probably go with one full set-up from one racing team, like Roush or Steeda or FRPP.

I think the OEM shocks that come on the GT are manufactured by Tokico for Ford. In which case, the FRPP handling pack may also contain Tokico shocks. Of course, these are not D-specs, because they are not adjustable.

The main problem may actually be your springs. The Steeda springs are geared more toward track days. They have a linear spring rate. The best ride quality (while still having a lowered stance) will come from a spring with a progressive rate. I think Eibach, H&R, and FRPP offer progressive rate springs. (The FRPP are actually Eibach springs, though made to Ford specs). Roush may also offer a progressive rate spring, I am not sure.

In any case, I have come accross other posting of people with Steeda springs exeriencing a harsh ride.

FWIW.

I am no expert, so this is all just what I have gathered from other forums in the past month or so doing research on a possible suspension upgrade.

Adjustable shocks will almost always have shorter lifespans then non adjustable units because of the added element of stress in the adjuster screw creating a failpoint from where the shock will leak and blow out.

Bilsteins are always and have always been fantastic shocks. The ride is compliant but controlled no wonder many premium european manufacturers use those in their performance models that cost thousand more. The Koni yellows are basically the American equivalent to that.

One of the last times I went autocrossing I worked corner with one of the operators and organizers of MSR Houston (the track) who also races in many touring and GT classes nationwide. I told him in the new car (the Mustang I just switched from my 240SX with a racing suspension) I wanted something simple like a well setup shock spring combo and not mess with anything adjustable. To that he said that's the best thing to do in a car you actually drive just get yourself some Bilsteins or Koni yellows with some nice springs and be done with it. Most people get adjustable shocks find the rate they want and never mess with them.

I know that's true after i set my old 240SX up I never touched a thing and was constantly having to deal with blowing shocks and an impossibly harsh ride.

GreyDiesel · Jul 23, 2009

Thanks for the info. I am currently addicted to finding all the suspension info I can, so this really feeds my buzz.

I just ordered the Steeda Pro-Action Dampers (non adjustable) with my Steeda Sport Springs, for the same reason you discuss. The concept of adjusting my dampers to match my springs seemed like a headache. I have done some engineering with resonance and damping before, and I know the difference between the correct setting and a nightmare can be very hard to find. I am hoping the Steeda Pro-Action Dampers do the job well. My concern is that they are no where near as good as Bilsteins. They were the same price, so I am banking on the fact that the Steeda dampers are tuned to the Steeda springs.

Just the other day I was downtown, at night, near the clubs, and everyone with a nice car was cruising the streets. I saw one new Camaro, several Porsches, a Ferrari, etc. etc. There was one lowered S197 Mustang with 20" rims. I thought, now see, that does look nice. More than holds its ground with all these nice cars. Then... it drove accross a nearbye intersection at about 40mph. As the rear hit the cross grooves in the pavement, it went bouncing around like cracked our kangaroo.

Totally ruined the cool.

walter · Jul 23, 2009

GreyDiesel said:
Thanks for the info. I am currently addicted to finding all the suspension info I can, so this really feeds my buzz.

I just ordered the Steeda Pro-Action Dampers (non adjustable) with my Steeda Sport Springs, for the same reason you discuss. The concept of adjusting my dampers to match my springs seemed like a headache. I have done some engineering with resonance and damping before, and I know the difference between the correct setting and a nightmare can be very hard to find. I am hoping the Steeda Pro-Action Dampers do the job well. My concern is that they are no where near as good as Bilsteins. They were the same price, so I am banking on the fact that the Steeda dampers are tuned to the Steeda springs.

Just the other day I was downtown, at night, near the clubs, and everyone with a nice car was cruising the streets. I saw one new Camaro, several Porsches, a Ferrari, etc. etc. There was one lowered S197 Mustang with 20" rims. I thought, now see, that does look nice. More than holds its ground with all these nice cars. Then... it drove accross a nearbye intersection at about 40mph. As the rear hit the cross grooves in the pavement, it went bouncing around like cracked our kangaroo.

Totally ruined the cool.

Yup, that's why you should tap into the expertise of the engineers that did their homework AND the racers that tried different setups. I went with Roush, I liked their system which can push you to 1+G on the skipad and still be comfortable dodging potholes.

To me the ultimate coolness is when you have a dab more dampening then you need for that hint of racecar bounce but not so that you go flying about like the car you saw (or somebody on cut springs)

walter · Jan 7, 2010

Thriller moment here resurrecting this thread from the dead.

Gray how did it go with your Steeda pro dampers? My Roush shocks died with less then a year of easy driving on them and seeing how many others had the same problem I did I wanted to go with something else. I see you got the Pro-actionI dampers how have those worked out for you?

I'll still retain the roush springs and sway bars but I want a shock that can last me a little while so it's back to looking at Bilsteins, Koni STR-ts, Steeda Pro Actions or the Ford Racing Multimatics....

Any ideas?

Anybody replace D-Specs with Bilstein HDs?

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