haiku88 Posted March 11, 2008 Share Posted March 11, 2008 this weekend and drove it 400 miles home yesterday. Love the car and the drive was easier than I expected as the car is fairly comfortable...though very snug. The only bad parts of the drive were a few stretches of of very rough broken concrete interstate paving (on I-5) where the car jumped about to an alarming degree. I'm guessing this is just due to the light weight of the car and normal for a Seven but wanted to check, it was pretty scary at the time.... Link to comment Share on other sites More sharing options...
Sean Posted March 11, 2008 Share Posted March 11, 2008 Congratulations! Man, that was fast - I had imagined it would take longer to find one to your liking. Link to comment Share on other sites More sharing options...
11Budlite Posted March 11, 2008 Share Posted March 11, 2008 Congratulations!!! What year is it, and do you have any pics??? "...where the car jumped about to an alarming degree" - Some of the Birkin owners (me included) have gone to Woody Harris' rear trailing arm kit to improve the rear tire contact over less than ideal roads. It might be worth looking into. Here's a photo I have at work: http://www.usa7s.com/aspnetforum/upload/892449239_IMG_0105.JPG Bruce :7drive: Link to comment Share on other sites More sharing options...
Kitcat Posted March 11, 2008 Share Posted March 11, 2008 Skittishness over bumps seems to be a Caterham/Birkin trademark. I don't think the weight of the car would cause it. My theory is it is stiff (track oriented) springs or stiff (track oriented) shock valving, or both. I assume the springs can be replaced with something softer, I am sure the Birkin experts here will know. The shocks can be re-valved to your liking. Places like Predatormotorsport.com will do it for about $100-$150 per shock, as I recall. They work on about everything. If you have Koni's, Koni of N America can re-valve (as can Predator, et al) Link to comment Share on other sites More sharing options...
Davemk1 Posted March 11, 2008 Share Posted March 11, 2008 Congratulations!!! What year is it, and do you have any pics??? "...where the car jumped about to an alarming degree" - Some of the Birkin owners (me included) have gone to Woody Harris' rear trailing arm kit to improve the rear tire contact over less than ideal roads. It might be worth looking into. Here's a photo I have at work: http://www.usa7s.com/aspnetforum/upload/892449239_IMG_0105.JPG Bruce :7drive: Money and time very well spent in my book. The side benefit is you can actually get the thrust angle of the rear axle set correctly. All good stuff. Dave Link to comment Share on other sites More sharing options...
slngsht Posted March 11, 2008 Share Posted March 11, 2008 congrats, and happy motoring! Link to comment Share on other sites More sharing options...
slomove Posted March 11, 2008 Share Posted March 11, 2008 Good Choice!!!!! I can not say that my Birkin is jumping about much but maybe that is just a matter of expectation? Obviously my Honda Accord has a somewhat smoother ride. Actually I increased the spring rates from standard 250lbs front/150 lbs rear to 325lbs front/175 lbs rear without noticeable detriment to the ride quality (4000 miles in 2 weeks last summer without calluses on my butt). I do have the ball joint radius arms (home-made) and changed to Protech shocks but I forgot how much it may have been worse with the stock setup. I would experiment with the shock adjusters and make sure they are almost turned CCW completely for most soft setting (plus a few clicks depending on the shock type). That said, I know that most Se7ens with life axle or DeDions tend to hop a little around bumpy curves. Not sure if that holds true for IRS models like Westfield or S2K. But it has never really bothered me. Gert Link to comment Share on other sites More sharing options...
haiku88 Posted March 11, 2008 Author Share Posted March 11, 2008 Thanks very much to all for the info, I will check out the spring rates and damper settings, sounds like what I experienced was more than usual Seven bouncing. My car is a 2004 w/ Dunnell Zetec power,it has 20K miles and I bought it from the original owner. Need to sort out a few issues, it is obviously running rich so I think maybe I'll convert it to an Emerald ECU after reading the positive reviews here...the original owner had some difficulty dealing with Dunnell and I don't want to repeat that experience. The expansion tank for the cooling system has a slight leak so I'll replace it with something better. Also the car is a little too loud, need to deal with that too...and that is added incentive for a new ECU so I can get the engine tuned properly on my own after a muffler swap. Only have a low quality cell phone photo so far....http://www.usa7s.com/aspnetforum/upload/1768991027_birk.jpg Link to comment Share on other sites More sharing options...
MHKflyer52 Posted March 12, 2008 Share Posted March 12, 2008 Only have a low quality cell phone photo so far....http://www.usa7s.com/aspnetforum/upload/1768991027_birk.jpg Man that looks real good for a low quality cell phone photo. I like the colors as well, blue and silver very sharp. I think you will find that the shock valves might be miss adjusted as with my car when I was playing with them I had a similar bounce from what you described as I ahd the rebound set way to soft and it was like driving a basket ball down the road and was very un-nerving to say the least. Glad to hear you made it home and are now enjoying your new car. Link to comment Share on other sites More sharing options...
southwind25 Posted March 12, 2008 Share Posted March 12, 2008 Some of the Birkin owners (me included) have gone to Woody Harris' rear trailing arm kit to improve the rear tire contact over less than ideal roads. It might be worth looking into. Here's a photo I have at work: Tell me more about this kit? looks nice. Is it simply an adjustable set of trailing arms? or is there more involved? are they aluminum? steel? Humbly admit we dont know Woody Harris, yet. what size (model etc) rod ends? inquiering Birkin minds want to know please. Link to comment Share on other sites More sharing options...
Davemk1 Posted March 12, 2008 Share Posted March 12, 2008 Some of the Birkin owners (me included) have gone to Woody Harris' rear trailing arm kit to improve the rear tire contact over less than ideal roads. It might be worth looking into. Here's a photo I have at work: Tell me more about this kit? looks nice. Is it simply an adjustable set of trailing arms? or is there more involved? are they aluminum? steel? Humbly admit we dont know Woody Harris, yet. what size (model etc) rod ends? inquiering Birkin minds want to know please. Woody's kit consists of rod ends in a machined aluminum tube. The big advantage of them over the stock arms the elimination of the stick-tion at the pivots. The stock arms have urethane bushings that have a high resistance to pivoting and in effect add to the spring and damping rates but a good bit. The reduced friction of Woody's kit allows for the rear suspension to be much more supple without it being soft. Call Woody @ MSI 707 448 3322. I've gotten a good number of things from Woody for my Birkin over the past few years and have been treated very well and he is a wealth of knowledge. Dave Link to comment Share on other sites More sharing options...
haiku88 Posted March 12, 2008 Author Share Posted March 12, 2008 Woody's kit consists of rod ends in a machined aluminum tube. The big advantage of them over the stock arms the elimination of the stick-tion at the pivots. The stock arms have urethane bushings that have a high resistance to pivoting and in effect add to the spring and damping rates but a good bit. The reduced friction of Woody's kit allows for the rear suspension to be much more supple without it being soft. Call Woody @ MSI 707 448 3322. I've gotten a good number of things from Woody for my Birkin over the past few years and have been treated very well and he is a wealth of knowledge. Dave Thanks, will definitely check those out...and MSI in general, they are nearby. Link to comment Share on other sites More sharing options...
slomove Posted March 12, 2008 Share Posted March 12, 2008 Thanks very much to all for the info, I will check out the spring rates and damper settings, sounds like what I experienced was more than usual Seven bouncing. My car is a 2004 w/ Dunnell Zetec power,it has 20K miles and I bought it from the original owner. Need to sort out a few issues, it is obviously running rich so I think maybe I'll convert it to an Emerald ECU after reading the positive reviews here...the original owner had some difficulty dealing with Dunnell and I don't want to repeat that experience. The expansion tank for the cooling system has a slight leak so I'll replace it with something better. Also the car is a little too loud, need to deal with that too...and that is added incentive for a new ECU so I can get the engine tuned properly on my own after a muffler swap. Only have a low quality cell phone photo so far.... That is Bud Darling's Birkin? Very nice car! I checked it out (only 3 miles from my home) for another potential buyer and liked what I saw. Link to comment Share on other sites More sharing options...
gjslutz Posted March 12, 2008 Share Posted March 12, 2008 Welcome Martin I’m also some what new to Birkins. My S3 was too loud and it was equipped with a Burns S.S. muffler. I repacked mine with S.S. wool. The original media was burnt out. It is much better now. My S3 had no skip at all, as I didn’t build it; I have no idea of what was used. When I purchased it the plan was to replace the rear with IRS, but there is no need on mine. Burns has a web site. Gary Link to comment Share on other sites More sharing options...
haiku88 Posted March 12, 2008 Author Share Posted March 12, 2008 That is Bud Darling's Birkin? Very nice car! I checked it out (only 3 miles from my home) for another potential buyer and liked what I saw. Indeed it is!...first one I looked at but I liked it so much I didn't check out two others, and Bud was a pleasure to do business with. Link to comment Share on other sites More sharing options...
haiku88 Posted March 12, 2008 Author Share Posted March 12, 2008 Welcome Martin I’m also some what new to Birkins. My S3 was too loud and it was equipped with a Burns S.S. muffler. I repacked mine with S.S. wool. The original media was burnt out. It is much better now. My S3 had no skip at all, as I didn’t build it; I have no idea of what was used. When I purchased it the plan was to replace the rear with IRS, but there is no need on mine. Burns has a web site. Gary thanks I will look at them, am also considering a DNA muffler after doing a search here and on the web... Bill Link to comment Share on other sites More sharing options...
Davemk1 Posted March 12, 2008 Share Posted March 12, 2008 thanks I will look at them, am also considering a DNA muffler after doing a search here and on the web... Bill I have a DNA and like it very much. dave http://www.usa7s.com/aspnetforum/upload/1686905587_DSC_7337.jpg Link to comment Share on other sites More sharing options...
WestTexasS2K Posted March 12, 2008 Share Posted March 12, 2008 We recently bought a Flowmaster Hushpower II muffler to use on the new car. We havent started it yet but it has noise cancellation chambers that are supposed to cancel out the high annoying frequencies. We hope to have the car running in the next 10 days or so. I will leave you some feedback on its performance. We have tried 3 different mufflers with poor results for the money spent at this point well over 600.00. So we are hoping this works as advertised. Link to comment Share on other sites More sharing options...
Kitcat Posted March 13, 2008 Share Posted March 13, 2008 The exhaust on my Caterham runs along the side of the car and under the rear axle and out the back. Other cars' exhausts end at the driver's left elbow, like the Birkin pictured just above this post. Maybe that makes a difference with the intensity of the sound? Link to comment Share on other sites More sharing options...
gjslutz Posted March 13, 2008 Share Posted March 13, 2008 Loren, My muffler is much like Davemk1’s photo above. I have not seen the DNA or Flowmaster Hushpower inside, when I opened mine up I liked what I saw. It is about 8” in Dia. and about 25” long. It has a perforated 2” pipe inside. The sound media chamber is outside the pipe in the surrounding chamber. The perforations are a series of .250” holes in the pipe. I could drop a 2” ball in one end and it would drop straight through. I think it had a ceramic cloth media inside that lasted less than 3,000 miles. I think you can get it with the S.S. wool from burns also. I’m not sure of any price points on the system or fill. I purchased my S.S. wool local, but when I called Burns they were very helpful on fill instructions. The only downside I see is the weight. Gary Link to comment Share on other sites More sharing options...
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