Ground Control/RA1 = 6+ seconds

[NEMustang]

This is how I made a 6+ second/lap (YES, 6+ SECONDS!) at NHIS from a stock setup. Sorry in advance for a longer post. However, this is an S197 Corner-carver discussion. I assume that you want details...

I had posted on this forum trying to fit 305 w/18x10 wheels on the front. with all the replys, no one, except custom SLAs, could fit 305s on front..given lack of confirmation that a 305 can fit on the front, I ordered 275 Toyo RA1 tires. ( Toyo does not make a 286 0r 295)...so either 275 or 305s.

Many posts on this forum and others indicate a non-staggered setup on s197 for road racing. Since the car pushed like a fat pig in the Showroom Stock Division (still won first place), I knew I need to change the understeer on the car

My selection was to use Ground Control custom struts with Koni sport inserts, custom valved and "inifinitely" adjustable rebound. Sure, you can go as fast as you want to spend. I found the GC system was used as a strut solution by Griggs Racing (If you don't know Griggs, you should research...not inexpensive...but top notch racing suspension).

For DD and 10-12 track day, I received the GC system in a 'stiffer' system than a DD set up...440# Eibach fronts wiht custom Valved Konis. 200# Koni rears. I lowered the car ~2" front and rear.

Changed tires to Toyo RA1 with/full tread. (~8/32) on 18x10 wheels( 40 mm offset) all around. I expected 2+ seconds from the tire change only.

Perfomance alligned the car to -2.9 camber, 6/5 caster, 1/8 toe out for track.

Tires set at 31 cold and ended up at 41-44 degrees track on day one(high in the middle...over inflated)...reset cold to 29 and was able to run 38 on all four for day two (worth over one second...yes, tire pressure matters). Longacre Pyrometer showed even across the back with slightly higher inside temps on the front.

With -2.9 camber on a quick turning track and a "new" corner with a bump caused a spin in lap 3 session 1. Mostly driver error due to .75 camber to new 2.9 camber, a big bump that was never there before and me driving . The turn in change from stock was incredible...no more Oink, Oink understeer..

Session 1 - Konis at full soft rebound. Car lowered 2" all around. 275/35/18 vs stock 235/50/18 (2007 GT/cs - 18" wheels) drops the car another inch with no suspension geometry changes...free CG improvement. The car was immediately 3 1/2 - 4 seconds quicker...I assumed 2 seconds with the RA1s...I was estatic with the additional two second. car was very loose compare to stock. Between the camber changes, spring rates etc. I could rotate the car at will...too much though...great set up for drifting. .

Session 2 - simple 1/4 rebound adjustment on front Konis to induce more oversteer (never thought I'd say that on an S197). The car was still prone to oversteer. Lap times improved .5 second.

Session 3 - 1/4 more rebound on front. Car fairly balanced and needed slight refiinent. Another .5 second.

Session 4 - adjust tires down about 3 lbs based on Pyrometer readings. Adjusted 1/8 rebound (more) on Konis...I gained another 1+ second

End result:
RA1 worth 2+
GC worth 2+
GC/Koni tuning worth 2+

Ground Control set up (extra 8.5 mm inset - no extra cost - can fit 305s all around!!!) for $1599.
Toyo RA1 =$720 - 275-35-18 (worth a 1" CG drop, no suspension change!!!)
Cheap Cruzin Control FR500 wheels - $550 ( at only 28 lbs). BTW, I 'lifted' by Buillits with 235/50/18 BFGs vs. CC FR500 with 275/35/18s and they were lighter...by a bit ( how's that for scientific data!).

Total = ~$2800...the 6+ second per lap, big grin on my face,on day two for a trophy...Priceless!!

 

[pieperz06]

This is how I made a 6+ second/lap (YES, 6+ SECONDS!) at NHIS from a stock setup. Sorry in advance for a longer post. However, this is an S197 Corner-carver discussion. I assume that you want details...

I had posted on this forum trying to fit 305 w/18x10 wheels on the front. with all the replys, no one, except custom SLAs, could fit 305s on front..given lack of confirmation that a 305 can fit on the front, I ordered 275 Toyo RA1 tires. ( Toyo does not make a 286 0r 295)...so either 275 or 305s.

Many posts on this forum and others indicate a non-staggered setup on s197 for road racing. Since the car pushed like a fat pig in the Showroom Stock Division (still won first place), I knew I need to change the understeer on the car

My selection was to use Ground Control custom struts with Koni sport inserts, custom valved and "inifinitely" adjustable rebound. Sure, you can go as fast as you want to spend. I found the GC system was used as a strut solution by Griggs Racing (If you don't know Griggs, you should research...not inexpensive...but top notch racing suspension).

For DD and 10-12 track day, I received the GC system in a 'stiffer' system than a DD set up...440# Eibach fronts wiht custom Valved Konis. 200# Koni rears. I lowered the car ~2" front and rear.

Changed tires to Toyo RA1 with/full tread. (~8/32) on 18x10 wheels( 40 mm offset) all around. I expected 2+ seconds from the tire change only.

Perfomance alligned the car to -2.9 camber, 6/5 caster, 1/8 toe out for track.

Tires set at 31 cold and ended up at 41-44 degrees track on day one(high in the middle...over inflated)...reset cold to 29 and was able to run 38 on all four for day two (worth over one second...yes, tire pressure matters). Longacre Pyrometer showed even across the back with slightly higher inside temps on the front.

With -2.9 camber on a quick turning track and a "new" corner with a bump caused a spin in lap 3 session 1. Mostly driver error due to .75 camber to new 2.9 camber, a big bump that was never there before and me driving . The turn in change from stock was incredible...no more Oink, Oink understeer..

Session 1 - Konis at full soft rebound. Car lowered 2" all around. 275/35/18 vs stock 235/50/18 (2007 GT/cs - 18" wheels) drops the car another inch with no suspension geometry changes...free CG improvement. The car was immediately 3 1/2 - 4 seconds quicker...I assumed 2 seconds with the RA1s...I was estatic with the additional two second. car was very loose compare to stock. Between the camber changes, spring rates etc. I could rotate the car at will...too much though...great set up for drifting. .

Session 2 - simple 1/4 rebound adjustment on front Konis to induce more oversteer (never thought I'd say that on an S197). The car was still prone to oversteer. Lap times improved .5 second.

Session 3 - 1/4 more rebound on front. Car fairly balanced and needed slight refiinent. Another .5 second.

Session 4 - adjust tires down about 3 lbs based on Pyrometer readings. Adjusted 1/8 rebound (more) on Konis...I gained another 1+ second

End result:
RA1 worth 2+
GC worth 2+
GC/Koni tuning worth 2+

Ground Control set up (extra 8.5 mm inset - no extra cost - can fit 305s all around!!!) for $1599.
Toyo RA1 =$720 - 275-35-18 (worth a 1" CG drop, no suspension change!!!)
Cheap Cruzin Control FR500 wheels - $550 ( at only 28 lbs). BTW, I 'lifted' by Buillits with 235/50/18 BFGs vs. CC FR500 with 275/35/18s and they were lighter...by a bit ( how's that for scientific data!).

Total = ~$2800...the 6+ second per lap, big grin on my face,on day two for a trophy...Priceless!!

i would think that it would be more than 6 seconds BWTHDIK

 

[danbev07]

Is it true you can order the Ground Control setup in double adjustable? I could have sworn on one of these forums I had read of someone saying they had done it... but I forget where.

Thanks for the info on setups. I've been looking into buying these myself.

 

[NEMustang]

i would think that it would be more than 6 seconds BWTHDIK

Based on the simple mods I have...shock, springs tires vs. what you have...you must be 30 seconds per lap - SAB.

 

[NEMustang]

Is it true you can order the Ground Control setup in double adjustable? I could have sworn on one of these forums I had read of someone saying they had done it... but I forget where.

Thanks for the info on setups. I've been looking into buying these myself.

Yes, they can put a double adjustable in the strut and provide DA's in the rear. The rear is not a coil over. The shock and springs are both in the stock location...My brother ran Moton 4-way adjustables and GC built the strut housing...they could build for any strut insert (I think).

Since the front S197s have springs over the struts, there is no suspension geometry changes..depends on how you interpret rules in each organization. I was running showroom stock and brought the changes to the orgs Chief Steward to be reclassified.

If you are looking at at DA setup, talk to Steve Strano or others about the KW Variant 3 setup. I liked the GC setup as Griggs Racing uses them for thier "low end" GR40 SS setup (not the GC rears). Anything will make an improvement. However, how do you get the best bang for your $$$. I liked the GC setup as I can tune the shocks (to a degree with SA Konis) and can corner weight the car (soon...).

There may be setups that you can pull 6+ of a shorter track (NHIS is 1.6 miles) for less. I'm just trying to communicate what I did and what I netted for times...I got a big grin and I know with some tuning, I should be able to improve the times...It was a big jump from stock, never having driven the new setup. It took 3 session to get the car fairly well balanced. I will continue to tune it and work for better times.

 

[ArizonaGT]

oh.

 

[pieperz06]

Based on the simple mods I have...shock, springs tires vs. what you have...you must be 30 seconds per lap - SAB.

i just know that tires brought me up more than that but i went from 255 310 tread ware tires to 275 r6's

 

[Vapour Trails]

I'd bet going from -0.75 to -2.9 camber had a lot to do with it.

 

[SoundGuyDave]

There's one part of the equation that you're missing: the driver. The overwhelming majority of us, myself included, are NOT what Ross Bently would call "non-learning drivers." That is, we're still learning how to drive our cars. Until you get to the point where you can turn fifty laps, all within one or two tenths of a second of each other, part of the equation, and I would argue a large part, is still down to the driver.

This really reinforces the "driver mod first" philosophy, to be honest. Based on the gains you made with the vehicle mods, I would bet you were getting just about all there was to get out of the stock setup. That took time and training, but once you got to the point where the car was consistently the limiting factor, then it was time to mod the car. So you did. Now, you have a much higher benchmark of performance, but you have already developed the driver skills to take advantage of the increased potential.

Honestly, based on the descriptions of the way the car handled, the changes you made, and the resulting balance changes, you pretty obviously know what you want out of the car, and how to get it. Kudos to you!

 

[Liftedbronco]

"Ground Control set up (extra 8.5 mm inset - no extra cost - can fit 305s all around!!!"

So you fit 305's all around on 18x10's with a 40mm offset?
What are you referring to with the 8.5mm insert?
Now that you have some experience, what spring rates would you reccomend for a street/track day setup?

Whats your opinion on their cc plates?

 

[NEMustang]

There's one part of the equation that you're missing: the driver...

SoundGuyDave,

Thanks for the comments!

I agree...after I wrote a fairly lengthy summary of my experience, I realized I never mentioned seat time. Obviously, this is the most important. You can throw mods at a car, run faster times and still be a shitty driver. The key now for me (as always was...), more and more seat time. Using a basic Data Acquistion system and video, I can also analyze my sessions, look at where I lost time due to line, early lift, uneven or less than optimum braking, etc...This will help me understand where I was good and where I was not. However, applying this during the next track session is where it counts.

Once I have optimized my driving (a never-ending quest!) with this setup, I may decide on additional mods for tuning...but the priority is more seat time.

 

[NEMustang]

"Ground Control set up (extra 8.5 mm inset - no extra cost - can fit 305s all around!!!"

So you fit 305's all around on 18x10's with a 40mm offset?
What are you referring to with the 8.5mm insert?
Now that you have some experience, what spring rates would you reccomend for a street/track day setup?

Whats your opinion on their cc plates?

The distance between the GC strut and the wheel is 8.5 mm more than the distance between the stock strut and wheel. I have about 7/8-15/16 clearance between the wheel and the strut...I have an inch clearance between the tire and the strut (275/35/18x10, 40 mm offset). A 305 RA1 (Hoosiers are different I'm told) would be a 30mm wider tire. 30mm is just under 1 3/16...the 305 would split to 15mm on each side (just under 19/32). Theoretically, if you only had 5/8 clearance between the strut and the tire, a 305 would just fit. I should have a 3/8 clearance between the 305 and strut, since I started with an inch clearance.

I had posted on this forum and others looking to see if anyone had fit a 305 front with non-SLA suspension. No luck. After I bought the wheels and tires, got the struts and fitted everything, I calculated that a 305 would fit with the GC struts and custom offset mount. I was hot for 305s as Toyo was selling them for $50 less than a 275. If I new I could fit them, I would have bought them.

"Theoretically", the 305 should fit.

The Koni sports are custom valved by CG to match the spring rates. My setup is for a DD that will have ~15 track days (less than some, more than most with a DD). Therefore, we went with a little stiffer setup. #440 front/#200 rear Eibach springs. I drove the car for about 1 week with the new setup (street tires- BFG KDW 235/50/18x9) on the street, into Boston over the Tobin bridge (talk about a shitty road) and the car was well behaved...not too stiff for me, but definetly stiffer. Camber was set at about -1.5 and the car was flat, good turn in and was a joy to drive.

The CC plates are an "under mount" style. The struts come completely assembled and installed in about 45 minutes (both sides and ride height adjusted). The quality is excellent...beefy mounts...and the whole assembly must be about #15 lighter than stock struts. Camber adjustment is simple...loosen four bolts and move the strut in or out. all the way in gives me ~3.2 negative, all the way out give me ~1.5 negative camber...simple to set. I had my alignment guy index different settings so I can change quickly from track to street (careful of toe changes).

Overall, I am very happy with the new set up...now, more seat time!

 

[Liftedbronco]

nice. I am familiar with GC as I have that setup on my 944. Looking into it for the mustang. How is the caster adjutment? easy to do? That seems to be a hot topic as some cc plates have caster adjustability and some dont.

Thanks for explainig the tire clearance for me.

 

[NEMustang]

nice. I am familiar with GC as I have that setup on my 944. Looking into it for the mustang. How is the caster adjutment? easy to do? That seems to be a hot topic as some cc plates have caster adjustability and some dont.

Thanks for explainig the tire clearance for me.

Jay, from GC, gave me street and track starting specs:
Front camber
street -1.8
track -3.2 or max (usually)

Front toe
street +1/8 in
track -1/8 out, maybe -3/16
NOTE:
Track toe out will usually end up track correct after shifting to track camber anyway, street toe-in is the priority.

Caster
street -even
track -even, no change

We noted upon alignment that the caster did not change with the camber changes and was about 6.5...Jay indicated that there is only about 1 degree adjustablility in Caster. There is room in the slots to simply slide the strut top from rear of car to front to change caster...not much adjustment, but you shouldn't need any. While Jay recommended -3.2 camber, we brought it into about -2.9 and it was plenty. I might to to -2.8...boy, does it turn in quicker!

 

[Liftedbronco]

thanks! Ive spoken to jay many times. GC has the best support of any vendor ive ever dealt with. BY FAR

 

[Sam Strano]

The distance between the GC strut and the wheel is 8.5 mm more than the distance between the stock strut and wheel. I have about 7/8-15/16 clearance between the wheel and the strut...I have an inch clearance between the tire and the strut (275/35/18x10, 40 mm offset). A 305 RA1 (Hoosiers are different I'm told) would be a 30mm wider tire. 30mm is just under 1 3/16...the 305 would split to 15mm on each side (just under 19/32). Theoretically, if you only had 5/8 clearance between the strut and the tire, a 305 would just fit. I should have a 3/8 clearance between the 305 and strut, since I started with an inch clearance.

I had posted on this forum and others looking to see if anyone had fit a 305 front with non-SLA suspension. No luck. After I bought the wheels and tires, got the struts and fitted everything, I calculated that a 305 would fit with the GC struts and custom offset mount. I was hot for 305s as Toyo was selling them for $50 less than a 275. If I new I could fit them, I would have bought them.

"Theoretically", the 305 should fit.

The Koni sports are custom valved by CG to match the spring rates. My setup is for a DD that will have ~15 track days (less than some, more than most with a DD). Therefore, we went with a little stiffer setup. #440 front/#200 rear Eibach springs. I drove the car for about 1 week with the new setup (street tires- BFG KDW 235/50/18x9) on the street, into Boston over the Tobin bridge (talk about a shitty road) and the car was well behaved...not too stiff for me, but definetly stiffer. Camber was set at about -1.5 and the car was flat, good turn in and was a joy to drive.

The CC plates are an "under mount" style. The struts come completely assembled and installed in about 45 minutes (both sides and ride height adjusted). The quality is excellent...beefy mounts...and the whole assembly must be about #15 lighter than stock struts. Camber adjustment is simple...loosen four bolts and move the strut in or out. all the way in gives me ~3.2 negative, all the way out give me ~1.5 negative camber...simple to set. I had my alignment guy index different settings so I can change quickly from track to street (careful of toe changes).

Overall, I am very happy with the new set up...now, more seat time!

I'm glad you are happy, just a few points.....

1. Ground Control does NOT revalve Koni Sports for the S197, they are using some other Koni (and god knows what it really starts as). EDIT: When I say God know's what they start as that's not imply they aren't some sort of Koni part--I'm sure they are. I just meant they are not starting out as 8741-1494 Sports which is the off the shelf strut for the S197 car.

2. I did a suspension a few years ago on a Camaro (not coil-over that posted a 6.9 second a lap improvement @ Old Bridge Raceway Park (read: Englishtown) NJ's 1.5 miles road course, starting with a 1:30 baseline--and the tires weren't RA1's, but Nitto 555R2's which are similar but not the same. And did it with -2 camber.

3. I don't believe you need -2.9 camber, that's more than I run and more than I need on my cars with softer springs than what you're running and I get great tire wear.

4. A 295 fits on a 10" wheel with a normal strut. I've had 295/30-18 Hoosier A6's on my car that way with 45 offset wheels. Run a 40 and a 305 should be no problem without any fancy offset built in the coil-over (not necessary). In fact I have a customer who runs 315's on the front of his S197.

5. All camber plates for this car are under the tower mounted.

 

[Liftedbronco]

I was thinking that sounded like a TON of camber..but thought "what do i know?"
SO GC is actually lying when they tout their "custom valved" konis? Thats a serious accusation.

Raceway park - you from around here sam?

 

[Philostang]

I was thinking that sounded like a TON of camber..but thought "what do i know?"
SO GC is actually lying when they tout their "custom valved" konis? Thats a serious accusation.

Glad I wasn't the only one...to think both that this was a ton of camber and that I don't really know diddly to say one way or another.

But the other part? I thought Sam suggested that GC wasn't using the Sports as the basis of their customization, not that they weren't using any Koni shocks whatsoever. One claim is a charge of miscomunication somewhere down the line...the other is a charge of lying.

I run the Sports, so I'd be curious to see anyone's thoughts on how different they are from what GC has put together (aside from the obvious, which is that they're coil-overs).

Best,
-j

 

[Liftedbronco]

they definitley use koni inserts. I have them on my porsche. Im just saying imo their claim to fame is that their konis are revalved in house to match the individual application. This was something that set them apart to me.

 

[NEMustang]

I'm glad you are happy, just a few points.....

1. Ground Control does NOT revalve Koni Sports for the S197, they are using some other Koni (and god knows what it really starts as).

2. I did a suspension a few years ago on a Camaro (not coil-over that posted a 6.9 second a lap improvement @ Old Bridge Raceway Park (read: Englishtown) NJ's 1.5 miles road course, starting with a 1:30 baseline--and the tires weren't RA1's, but Nitto 555R2's which are similar but not the same. And did it with -2 camber.

3. I don't believe you need -2.9 camber, that's more than I run and more than I need on my cars with softer springs than what you're running and I get great tire wear.

4. A 295 fits on a 10" wheel with a normal strut. I've had 295/30-18 Hoosier A6's on my car that way with 45 offset wheels. Run a 40 and a 305 should be no problem without any fancy offset built in the coil-over (not necessary). In fact I have a customer who runs 315's on the front of his S197.

5. All camber plates for this car are under the tower mounted.

1. I asked GC again and same answer. I will pose the question to Koni and see if they respond.

2. You're a better driver. You're comparing an s197 Mustang and Camaro? You drive both so you're better qualified than me. So you went from completely bone stock Camaro and changed to Nitto 555R2's with no other changes? With all the induced body roll (no spring change, no shock change, no Strano adj roll bars, correct?), beating up the brakes (no brake pad/rotor change, correct?) and were 6.9 seconds faster on tire only? You're a way better driver than me (we all knew this anyway!). This means that no one needs to change anything except tires and should be able to get 4-7 seconds quicker. A lot of people could have saved a lot of money.

3. You're right. I thought the turn in was too quick inducing over steer too easily. I took GC recommendations, Griggs Racing recommendations (they run the same GC Strut as part of their GR40 SS setup) and Toyo's recommendation of -2.5 or less (more negative) for the RA1 and settled on 2.85 (just looked at my alignment sheet again).

4. I had two threads on this subject. You provide great tech on this site. Thanks! I'm sorry that you didn't see my postings about fitting 305s and could have responded. GC builds the strut housing and mounts. The offset is no cost...and about 15 lbs savings per side.

5. I have only seen CC plates on SN95s and they were on top. I didn't know all S197 CC plates were under mounts.

Sam, thanks for your input. Hopefully, you don't misinterpret the tone of the response in #2. I'm guess that I'm surprised that you'd go to such a sticky tire without any other changes. Or maybe you simply didn't list them. I would assume (bad idea), that you induce body roll and brake abuse with stock to r-compound tires.