Davemk1

One thing to keep in mind......stiffer is not always faster. If stiffer was always faster then the logical conclusion would be to do away with the springs and have the suspension be solid with zero wheel travel. Since this clearly won't be the answer and at the same time super-soft springs aren't the answer this means that we have a Goldilocks situation where one end is too soft and the other is too hard and the one is the middle is just right. Finding that one in the middle is much harder than it might seem and is the Holy Grail. Lastly - autocross is not road racing. The two types of cars require MUCH different set ups. Road racing tends to have very stiff set ups and all too often Solo guys tend to look at what they have done and copy it. This will seldom end up working well for solo. Road race cars are driven on lots of steady state situations where the car takes a set and the car is balanced there for longer periods of time. Transitions in road racing are not that fast.....Solo on the other hand is a 99% super-fast transition and steady state corners are very rare. So Solo cars need to be set up so that they transition well. Often this means that both springs and shocks will be softer than the road race set up so that the car can take a set in one corner before the driver asks it to turn the other direction. There's lots of good reading out there on this and it's very cool when you get the set up right...or closer to right....and the car just sticks and flows. Do you know the weight of your car? Do you have the 6 or the 8? dave

I don't know the particulars on the spring rates of these two cars but there are certainly many reasons it might be this way. The most obvious is that the Stalker no doubt weighs much more (500 lbs?) and this of course would necessitate stiffer springs. The other reason could be that the leverage ratio of the two different suspension designs is likely much different. The angle that the shock sits from vertical can be a rough indicator of the leverage ratio. Where the shock attaches to the A arm compared to the tire contact patch of the tire is another (if the shock attaches far inboard the spring needs to be stiffer to give the same effective spring rate). And of course is the suspension uses a rocker arm set up all bets are off. Typically the spring rates are chosen to give the car a given amount of static sag (measured as a percentage of shock travel) so that the wheel can move both up and down from its "home" position. If the springs are too stiff the car will sit with the shocks topped out (or nearly so) which means that if the ground drops away (or the car unweights) the tire can't reach down for the surface and will become unweighted and traction will be lost. At the same time if the springs are too stiff the wheel will not be able to move up enough when it encounters a bump and the tire will become overloaded and traction will be lost. I have no idea if the spring rates you have fitted will make the car autocross better or worse.....that said it's easy to over-spring a car and have it feel fast (quick turn-in, very little lean....etc) but ultimately have the car end up being more difficult to control at the limit and slower against the clock. Typically speaking having springs that are a bit softer than optimal will make for a car that is slower than one fitted with springs that are a bit stiffer than optimal. You'll know if the springs are too stiff if the car feels disconnected from the surface....it will feel "skippy" like a stone skipping across the water. It will still feel fast.....in fact it might feel very fast due to the quick turn in and lack of lean or brake dive but if it's not connected it will actually be slower. If the car feels faster but is actually slower it could be that your spring rates have been made too high. dave

The diff is now sold and paid for - thanks for the interest. dave

This diff was removed from my Westfield only because I wanted to change the rear end ratio and it functions perfectly. It was supplied new from Westfield and has about 4000 miles of use. Here's the specs - Ford Sierra 7" differential Quaife ATB limited slip 3.9 gear ratio About 4000 miles of use. The price is $650 and the buyer pays true shipping cost from my location in Bozeman, Montana - zip code 59715. Payment by paypal please. If interested it would be best to email me directly at info@kirkframeworks.com and I'll do my best to get right back to you. Thanks for looking. Dave

You are of course correct....4 tires will grip better than 3....in most cases. The corner is smooth and there's no bump. The spring rates are 300 front and 200 rear and the front bar is pretty soft. The tires will generate massive grip and if you look carefully you can see that even the inside rear is fairly light (nothing like the front of course). It will three wheel only in a very specific circumstance....it has to be a hard right turn taken at speed and full throttle at corner exit. My body weight is right over that left-rear tire so when I corner hard to the right the whole right side of the car is light and then when you are under full throttle the weight shifts to the rear loading the left-rear tire heavily....which in turn lowers the amount of weight carried by the right-front. One look at the tire deflection on the right rear will tell you just how much work it's doing....and the more work it does the less work the tires on the other side of the car will be doing. Interestingly it will never three wheel in a left turn due the lack of weigh on the right side of the car. FWD VW's will lift an inside rear under the combo of heavy braking and a sharp turn in. This is doing the exact opposite to what my car is doing in the photo. The VW has shifted much weight (braking and turning) to the outside front tire unweighting the inside rear. I'm shifting the weight to the outside (right) rear (and my butt is right over that tire) through using all 250ish hp and cornering hard. The handling is wonderful and balanced and exploitable and on the very rare occasion where it lifts that right-front tire you can't feel it at all. All you can feel is the lateral g's like you are being swung around on a rope. It's very quick. I took FTD at this event by 1.9 seconds over a GM factory built race car (mid engine, 500 hp V8, full tube frame, Porsche transaxle...) with much wider and stickier slicks. Like I said....it's very quick and easy to drive. And oh so much fun. dave

1st - thanks 2nd - the mirrors are the common Spa mirrors but I made longer stems for them so that I could see something other than my shoulder. The aero screen is by Aerodynamix and it seems they have gone under. The front fenders are by Carbon NV and they certainly ship to the USA. The quality of the fenders is very good and I'd go to them for an aeroscreen for sure. dave

The winter is long in Montana and when spring finally does arrive it's great to feel some tires really grip the pavement. I love that feeling like you are being swung around on a rope! Dave

That's good news.....enjoy your cool car! dave

Is the car fitted with an inertia switch? They are designed to cut fuel during an accident and can be triggered by a big jolt. My Lotus Elise had one and my current Westfield is wired for one but I left it off. If you have one all you need to do is reset it and you should be good. dave

I have a good and local friend who is heavily involved with the Kurtis brand and he has a Facebook page dedicated to the brand. If you are on FB it's worth the time - https://www.facebook.com/groups/788669467822168/ dave

The SCCA national rules are still the same....DM is limited to 2.0L and when you go above that you need to run in EM. The tough part is that you need to meet the minimum weight for EM which in most cases will mean a lot of ballast. As I recall the min weight on a Seven type DM is 1420 lbs and for EM it's 1750 lbs. I would expect this means that one would need to add about 300 lbs. I've not tried to do it but i should think that is would be pretty tough to find a place to put 300 lbs of anything in a Birkin. I wonder if you can just bump yourself up to AM to be fair to those running in DM and/or PAX? I'll bet the 2.5 L will be really fun where ever you run it. dave

That sounds like fun. What class will you run it in? have fun! dave

Cool, I completely understand. If you are serious about having a S2000 engine in the car you might reach out to the importer of Westfield - Manik - http://www.manikllc.com/ . There was some talk of them being able to bring in turn-key cars that are ready to drive this year. It's a wonderful car. dave

I'm sure if one is handy and crafty that you could stuff an S2000 drivetrain in most Sevens but I think the Westfield Mega S2000 is the only Seven built to work with the Honda set up from the start. It's a plug and play deal and works very, very well. Here's my car this past fall near my home in Bozeman, Montana. If you have any questions about building a Westfield just let me know. Dave

I owned a Birkin years ago with a solid rear axle and it worked very well as long as the road was smooth. If it was bumpy or ripply you could certainly feel the back end struggling to stay on the floor. If you buy a Birkin with a live axle I would strongly advise changing the track rods out for something with rose jointed ends if it's not already set up that way. My car had the stock rubber metalastic bushings which limit roll and give way too much roll stiffness and make the car very tail happy. I put new rods in and they were better in every way....smoother ride and more predictable handling. I think the first thing to consider is do you want a more traditional Seven type car (Lotus, Birkin, Westfield...etc) or do you want one with a more hot rod type character like a Stalker. They have VERY different characters and feels to them and I think some will love one and not the other. I owned a Birkin many years ago and now have a Westfield and while they are much different in design they have a similar feel and character.....and this feel is certainly my personal preference. As for the quality.....I think most of the quality that you will find in these cars stems from the peson who built it and less from the design. My Birkin was poorly assembled (I bought it used) and it took me a very long time to bring it up to a level I was happy with. I'm a very detailed (anal) guy who builds very high end bicycle frames for a living and the build quality of the Birkin I bought was not up to snuff for me. When I went to get in a Seven type car again I chose the Westfield Mega S2000 and bought it as a complete kit so I could control every little thing about it and now I really enjoy having things be just the way I want them to be. Plus with the Honda S2000 engine running throttle bodies it's very quick and has more than enough power to really make the car move. So.....what type of experience do you think you'd want? Traditional Seven or a Stalker with a V8? dave P.S. - One thing I forgot to mention - if you buy a Birkin with a Zetec the exhaust is on the driver's side and I found that very tiring on a hot day. All that noise right at hip level along with the heat was a bit of a bummer for me personally. When I went shopping for a second Seven it was down to the Birkin with a Duratec of the Westfield with the Honda S2000 because both put the exhaust out on the passenger side. So nice not to have to worry about stepping over that hot thing between autocross runs!

I don't know enough about the properties of aluminum to speak intelligently but it seems odd that the heat of powder coating would affect the hardness of the wheels. Powder coat typically needs to run at 425° - 450° to get the epoxy in the powder to do its thing and it seems surprising that this would be hot enough to change the molecular structure of the alloy. Does anyone here know enough about aluminum to say for sure? dave

I would think the tire brand/model/compound would factor in as much as the width. Do you know what tires you will be using? dave

Is there a lower profile cap that you can fit? Lower motor mounts that can drop the whole lump down enough? dave

When I suspected the dry collar I decided to do a diagnostic test first. I strongly suspected the clutch needed replacing anyway but didn't want to jump right into it as I had some time left in my short driving season.....so....I sprayed some spray grease into the area through the slave cylinder opening. I knew this would compromise the clutch but did't care as it needed to be replaced anyway. It took some creative spraying but once I figured it out and got some of the grease on the sliding collar the resistance went way down. The spray grease is crap and didn't last long but it told me what I needed to know. FWIW my clutch felt like it sounds yours does.....even take up and "normal" aside from the very high effort. I assume Westfield had given me the wrong size master but that wasn't the case in the end. Frankly the design is weak......you spread grease on the parts and they are exposed to air so the grease dries and wears out in time. My engine is from 2001 so that grease had sat in there drying for 15 years. That is a long time to expect it to do its job. if yours has never been apart I've got $100 that says the grease is toast and the collar is scored. It's super easy to fix once you are in there and Honda stocks the parts. While you're in there replace the stock flywheel with a lightweight Fidenza version and it will really allow it to spin up quickly. I'd plan on pulling it out sooner rather than later. dave

I hear you. That is what I found on my S2000 too (see post 3 above). I look forward to hearing who the OP's deal works out. dave

I use this engine and trans in my Westfield and when I first built the car the engine had 70,000 miles on it. I put it in the car and it was so hard to push the clutch that I thought it was broken. It turned out to function just fine but it was very stiff to push and I too suspected the size of the master might not be a good match to the slave. I'll save you the rest of the story but I ended up taking the engine and trans out for other reasons and when I looked at the throwout bearing I could see the issue. The Honda throwout slides on a collar and this collar is supposed to have a special Honda grease on it and mine was bone dry and badly galled. I replaced it and used the proper grease and the pedal effort was much, much lower. Now it feels normal and good. So.....it's certainly possible that yours is the same way and that all that pedal effort is being put into grinding the bearing in/out on the collar. Something to check. I hope that helps. Dave

Windage tray not in place? dave

I owned a live-axle Birkin years ago and autox'd it a lot. It had an open diff and spun the inside wheel all the time. I put a quaife in it and it worked perfectly. No wheel spin and no understeer. After the first few solo runs I forgot about it. I've driven, but never owned, a few cars with welded diffs and they just flat out sucked. Unpredictable rear end behavior but totally predictable front end push during acceleration. It sounds like Quaife doesn't offer their LSD anymore? Is that right? That would be a bummer. I'd search long and hard for one. dave

I'm using the Mintex 1144 and like them very much. Great cold bite and not fade. I've not tracked them, only autox and street. dave

Thanks for the interest - they are sold and paid for. dave