"...Not gonna go an faster in this car without taking out your wallet..."

[rastta]

I agree with Radium King for the most part. On my old TT - I eventually had all spherical joints in the front and rear suspension and poly motor mounts, camber plates, KWV3's etc. running -3 degrees on the street. It does get old.

However - you mentioned the R+T Ohlins. I have them on my Cayman and they are outstanding on the street - IMHO better riding than stock and batter handling. They are capable of only lowering the car 18-20mm. That's similar to a Porsche sport suspension so it isn't that low. The level of adjustment will get you more stiffness on track and if you ever get more serious, you can add stiffer springs and the valving will still work up to a point.

I just put Elephant Racing adjustable LCA's on my Boxster. They are high quality and completely rebuildable, including the boot and the joint. They don't require shims and are excellent quality and easily adjustable including having caster adjustment. They don't cost much more than a GT3 control arm with shims.

I run 240/40/18 and 275/40/18 rear on the Boxster and never have much of a problem with the rear end or understeer in the front. However, if you choose to street drive the car - with a lot of camber - you'll probably be better off running square so you can rotate them.

I also have the GT3 front and Tarett rear bars, but both are set on soft or near full soft, as I'm runnning 700/800 lb springs f/r. As for tires - I don't think NT01's can be beat without going to a full slick or other non-street legal tire.

If you are going to make changes, the best change would be the adjustable arms and good coilovers or have your Bilsteins serviced and put on spec boxster springs. That would be a cheaper start. If you have the coin though - the Ohlins will significantly outperm that setup on street and be equal if not better on track.

[MaxD]

For starters - you need to get to a consistent reliable platform.

It would help if you gave us your approximate winter/short term budget for car mods.

Front camber, springs/shock and tires would be my first priority. Then real data, Harry's is great but often optimistic.

You should have asked me for a ride along or a ride in my lowly "spec". The IRPCA's primary interest is keeping you "on" the track and in control. Going faster is not really a curriculum priority and many instructors don't race or do TT's. Did either of them ask you about your goals for the event?

I also instruct for NASA so grab me at the next event.

[Gilles]

Originally Posted by rastta

On my old TT - I eventually had all spherical joints in the front and rear suspension and poly motor mounts, camber plates, KWV3's etc. running -3 degrees on the street. It does get old.

However - you mentioned the R+T Ohlins. I have them on my Cayman and they are outstanding on the street - IMHO better riding than stock and batter handling.

Hello Rastta,

Very curious about your experiences between the KW-V3's and the Ohlins, since you had both of them..

I had the KW-V3's on my 987 CS for a few years and was very happy with them, and they wear down pretty good (+/- 50k..) before you have to rebuilt them, and if I remember correctly the minimum lowering height was about 1.2 or 1.5" .. I am not looking for lowering more that 1.5"

I no longer have the 987 and the coilovers are not compatible with the 981 chassis therefore I sold the freshly rebuilt KW's and just looking for other alternatives.

The cost of the JRZ's are not much more than the KW's but according to JRZ you should rebuild them around the 20k miles mark which is almost 1/2 of the miles required for the KW's (the cost for rebuild is $750 for the KW's and $900 for the JRZ's) however, I believe that the JRZ's are superior than the KW's for track use.

My intended use will be mostly street driven car with the occasional track day, that is after addressing the 981 cooling with the center radiator to help cooling on the PDK..

You would be the first person that will share (with me) some comparison on both KW's & Ohlins, thank you in advance.

[rastta]

Originally Posted by Gilles

[/B]

Hello Rastta,

Very curious about your experiences between the KW-V3's and the Ohlins, since you had both of them..

I had the KW-V3's on my 987 CS for a few years and was very happy with them, and they wear down pretty good (+/- 50k..) before you have to rebuilt them, and if I remember correctly the minimum lowering height was about 1.2 or 1.5" .. I am not looking for lowering more that 1.5"

I no longer have the 987 and the coilovers are not compatible with the 981 chassis therefore I sold the freshly rebuilt KW's and just looking for other alternatives.

The cost of the JRZ's are not much more than the KW's but according to JRZ you should rebuild them around the 20k miles mark which is almost 1/2 of the miles required for the KW's (the cost for rebuild is $750 for the KW's and $900 for the JRZ's) however, I believe that the JRZ's are superior than the KW's for track use.

My intended use will be mostly street driven car with the occasional track day, that is after addressing the 981 cooling with the center radiator to help cooling on the PDK..

You would be the first person that will share (with me) some comparison on both KW's & Ohlins, thank you in advance.

The primary difference is in the valving of the Ohlins and adjustability. The DPV valve acts like a blow off on the street, so sharp bumps that you thought would be jarring are handled really well. I'm amazed at how compliant they are for coilovers that have 400/462lb springs f/r. While it's hard to directly compare to the TT, the Ohlins have a much better ride overall, no matter how I would have adjusted the KW's. If you are looking just for a track shock, then JRZ's are a good way to go, but there are also lots of other good choices.

Lastly, KW uses injection molded pieces on there show for spring perch etc. They are also an odd size as are there springs. So if you want to change springs - you have to change all the hardware. I did have one spring perch crack.

IF you are using on a car that will see a lot of miles on the street, I just don't see how you can go wrong with the Ohlins.



They are also intended for the street, so seals and construction are more on the street side than the track.

[jsceash]

AS for Weight loss my diet was as follows, this is my best recollection but I'm certain it's posted on here from a couple contributors.
1. Ditch the exhaust Headers with alternate mid pipes and mufler can net an easy 50#?
2. Trunk liner Frunk liner carpets and plastic parts about 20#
3. Coil overs for struts and springs 20#
4. AC compressor and radiator and tubes 20#? + HP
5. PS pump and under-body and motor tubing 5# + HP
6. Track seat 5 point harness for power seats 40#
7. Engine cover carpet and firewall carpet 25, 30#
8. Track tires and lightweight wheels 5-10# each
9. Light weight battery 15-20#

[78F350]

Originally Posted by jsceash

AS for Weight loss my diet was as follows,...

Reminded me of a recent thread on another forum. Too late for you to get the shirt, but the concept represented on the shirt applies: 16 oz = 1 lb.
https://grassrootsmotorsports.com/forum/grm/16oz-1lb-im-making-shirts-again/143063/page1/

[maytag]

Originally Posted by 78F350

Reminded me of a recent thread on another forum. Too late for you to get the shirt, but the concept represented on the shirt applies: 16 oz = 1 lb.
https://grassrootsmotorsports.com/forum/grm/16oz-1lb-im-making-shirts-again/143063/page1/

Ha! I love it!

Does anyone have a simple equation that shows the relationship between weight loss vs HP? As-in: If I lose 100lbs, it's like gaining xx hp"?

[husker boxster]

Interesting thread. Not sure what I can add, but here goes...

I have GT3 LCAs along with Tarett monoball bushings, thrust bushings, and rear toe arms. I have my camber set to -2.5 F & -2.1 R. The track alignment has helped prolong the life of my tires on the track. I run street tires (Conti Extreme Sports) along with stock rotors and Stop Tech Street / Track pads. Since my CSS is both a street and track car, my goal is to keep it as streetable as possible, knowing I will give up some performance on the track. I drive my car to and from the track. My original plan with the track alignment was to set it in the spring and leave it in place during track season, then set it back to stock when I put my snows on and use it as my "winter beater". During the track season, I drive my LE as my daily driver. However, life got in the way as 2 yrs ago my new boss decided I'd become a bad employee and let me go after 35 yrs at Mutual of Omaha. So I decided to just leave the track alignment on full time. I don't drive as much now that I'm "semi-retired", so I don't worry about burning off the inside edges of my snow tires. I discovered the insides haven't worn off very much, even on my summer tires, so it hasn't been expensive to leave the track alignment on.

It's not easy for me to compare times with others. Most of the cars in my local DEs are different than mine. And if there are similar cars, you don't know if they have tunes, or race tires, bigger brakes, etc. It's hard to compare accurately.

I left Indy last mo thinking I had driven it about as well as I could - that I'd reached the limit of my car. I thought about what I could do to reasonably take it mechanically to the next level. My first thought was to improve the brakes. Last summer, a friend of mine let me drive her 2014 CS and the brakes on her car were order of magnitude better than mine. I'm living on a tight budget until Apr next yr, when I turn 60 and will start taking my pension. At that time, I'll think about improving my brakes. That should fit my plan of keeping my car usable on the street while better on the track.

But then I started studying my videos. I've already seen several places I want to do different next yr. I've also studied my bonsai lap to determine why I was faster on that lap vs others. I did make an effort on that lap to set a hot time, so it might have been a 90-95% effort vs my normal 85-90. So maybe it won't be possible to run like that every lap, but there are things I learned, like I could accelerate earlier in certain places w/o kicking in the PSM. The other thing is I can be more consistent with hitting apexes. I will never be a machine and conditions of ea lap dictate where you drive, but being more consistent is a goal. jsceash's suggestion to view track segment data is a good one. I have the data from Indy but haven't run it yet. Have to add that to my To Do list. Bottom line is I thought I'd driven as well as I could, but it didn't take long to find some things to try next yr.

Keep the dialog flowing. Interesting thread.

[MWS]

Originally Posted by maytag

Does anyone have a simple equation that shows the relationship between weight loss vs HP? As-in: If I lose 100lbs, it's like gaining xx hp"?

Radium_King once posted "rule of thumb - 10 lbs = 1 hp" in the thread:
lightweight mirrors

Allow myself to quote myself (lol)...from the same thread:

"....I looked at the owners manual for some numbers, listed below (for a base w/ manual transmission):

217 HP ;Weight: between 2777 lbs and 2954 lbs, which I averaged at 2866 lbs; 0-60mph 6.5 sec

Now I understand that these numbers are not scalable, but for giggles, if they were:
2866lbs/6.5sec=441 lbs/sec or 0.002267 sec/lbs.
Given 5 lbs reduction, that would equal just 0.01133 sec reduction on the 0-60 time, or with a car stripped of 100 lbs, an increase of 2/10ths of a second 0-60...which somehow sounds about right (at least to me)....

I should stay away from numbers, and stop asking questions."

And I'll stand by that comment, or at least that I should stay away from numbers

[MaxD]

Lots of good advice and you can really see a theme.

You want an initial stable build so you can measure improvements. A baseline to start with, then start getting data on what works for that setup and how the driver responds to it.

I'm a fan of AIM stuff. I would suggest considering a Solo, new or used.

Don't worry about running GT3 LCAs on the street. If you run 0 toe in the front they will be quite streetable even with -3 degrees camber. No need to have street and track settings. Also they have rubber bushings in them and are actually intended for street use.

Also, don't bother with the Boxster Spec PSS9 shock. They are really a glorified street shock and Bilstein is so behind that they have been on backorder for the last year. Spec Miata just ditched Bilstein and went with Penske for their spec shock. Wish we could do the same.

[Gilles]

Originally Posted by MaxD

Spec Miata just ditched Bilstein and went with Penske for their spec shock. Wish we could do the same.

Really curious about the cost of the Penske coilovers for the Spec Miata, because when I checked on the Penske website for the 981 I knew right away that would not be able to afford them...
Penske promotes them as a great street and track setup, which I believe they are but...