"Or you can do like they do in NASCAR racing and "put a couple of clicks in the rear wedge."
I'd rather have 'a couple of chicks in the rear seat'. That would make my steering geometry work well.
Rooster Robert and his two chicks in the back. I'm telling your wife.
Ron
Ron
Erik is correct in stating that if the geometry of the car is setup properly bump steer will not be a problem ever because it is a fixed relationship amongst several immovable connection points. Obviously John
I am still trying to understand the described handling situation.
Charles, could you make another attempt? Were you saying it is a question of matching a particular tire to the requirements of the chassis, or are the symptoms as described hinting that a set-up adjustment is needed.
OEM manufactuers design their cars with a specific tire in mind. Obviously when purchasing replacement tires it is best to buy the same design tires. But when fabricating a frame and adding aftermarket suspension components the chain is only as strong as its weakest link. Admittedly Steve is smarter with setup than me due to his extensive automotive background, it seems to me the tires/handling may be a symptom and not the cause. With the mid-engine design the f/r weight distribution is fantastic. Could it be something as simple as different shocks which keep the wheels firm on the road?
Charles, could you make another attempt? Were you saying it is a question of matching a particular tire to the requirements of the chassis, or are the symptoms as described hinting that a set-up adjustment is needed.
OEM manufactuers design their cars with a specific tire in mind. Obviously when purchasing replacement tires it is best to buy the same design tires. But when fabricating a frame and adding aftermarket suspension components the chain is only as strong as its weakest link. Admittedly Steve is smarter with setup than me due to his extensive automotive background, it seems to me the tires/handling may be a symptom and not the cause. With the mid-engine design the f/r weight distribution is fantastic. Could it be something as simple as different shocks which keep the wheels firm on the road?
Erik
I was trying to say that the issue can be very complex. I am just glad that the auto manufacturers have people that worry these things. I will say that one should be careful before changing the tire diameter significantly. Many manufacturers offer several wheel/tire options but if the wheel diameter increases, the tire profile usually decreases so all remains similar. For an article on all this stuff, you might read www.rqriley.com/suspensn.html
I was trying to say that the issue can be very complex. I am just glad that the auto manufacturers have people that worry these things. I will say that one should be careful before changing the tire diameter significantly. Many manufacturers offer several wheel/tire options but if the wheel diameter increases, the tire profile usually decreases so all remains similar. For an article on all this stuff, you might read www.rqriley.com/suspensn.html
I found this site for a tire diameter calculator
www.rx7turboturbo.com/robrobinette/tire_diameter.htm
You can put in the sizes and see what the diameter is and try to keep the diameter you want. For instance a 205/55x16 is 24.88 inches tall. A 235/50-15 is 24.25 inches tall. A 275/45-15 is 24.74 inches tall. A 165/75-15 is 24.74 inches tall.
www.rx7turboturbo.com/robrobinette/tire_diameter.htm
You can put in the sizes and see what the diameter is and try to keep the diameter you want. For instance a 205/55x16 is 24.88 inches tall. A 235/50-15 is 24.25 inches tall. A 275/45-15 is 24.74 inches tall. A 165/75-15 is 24.74 inches tall.
I like to use this tire calculator.
www.miata.net/garage/tirecalc.html
BD
www.miata.net/garage/tirecalc.html
BD
205/65HR15, 25.6" diameter, 5.9" tread width
With the Subaru horsepower I would want this kind of tread. I don't think a car with over a 120HP should be running on kelly 165's. If this is a tube frame car the designer should have designed for proper wheel clearance.
With the Subaru horsepower I would want this kind of tread. I don't think a car with over a 120HP should be running on kelly 165's. If this is a tube frame car the designer should have designed for proper wheel clearance.
Sounds like a simple complexity to me.
Switching gears (no pun intended) a little bit, what is the reason SAW cannot use a new Subaru engine and other parts? Perhaps it is my ignorance but I thought the "modern" components that SAW uses in the car was synonymous with "new"...I was wrong. Thoughts?
Andrew:
New is relative and the answer is cost. SAW can get almost new Subaru engines from rolled cars (some with less than a 1000 miles but nothing over 10K) that have been totaled by the insurance companies at a fraction of what new engines with all their components would cost. These components which make up a complete running car are all still there and available (wiring, A/C, computer controls, etc.). Go to a new car parts place and try and purchase everything that you need to complete a modern running car. I think you get my drift.
New is relative and the answer is cost. SAW can get almost new Subaru engines from rolled cars (some with less than a 1000 miles but nothing over 10K) that have been totaled by the insurance companies at a fraction of what new engines with all their components would cost. These components which make up a complete running car are all still there and available (wiring, A/C, computer controls, etc.). Go to a new car parts place and try and purchase everything that you need to complete a modern running car. I think you get my drift.
Charles,
I certainly do understand the cost reason. My feeling is, in getting an engine with no more than 25K miles (per Steve at SAW), I would be buying something that already has a shortened life and may be questionable as it is from a totaled vehicle (think about what caused the vehicle to be totaled in the first place...can this be good for the engine??). I would much rather pay a slightly higher price for a new engine that does not have this large unknown and, at the same time, get more than 6 months, 6,000 miles for a warranty on the car. In remaking the car to be a daily driver, I believe "modern" and "new" should be synonymous, seeing as it should be possible in this situation.
I certainly do understand the cost reason. My feeling is, in getting an engine with no more than 25K miles (per Steve at SAW), I would be buying something that already has a shortened life and may be questionable as it is from a totaled vehicle (think about what caused the vehicle to be totaled in the first place...can this be good for the engine??). I would much rather pay a slightly higher price for a new engine that does not have this large unknown and, at the same time, get more than 6 months, 6,000 miles for a warranty on the car. In remaking the car to be a daily driver, I believe "modern" and "new" should be synonymous, seeing as it should be possible in this situation.
I don't think Steve would mind at all ordering a new engine w/EFI from a Subaru dealership for any car he builds. It will add substantially to the final cost though.
With the computer testing features on these engines I suspect it would be simple to run a diagnostic test to get a confident idea of its health, that and a compression/leak-down test should tell the story re a "used" engine. Besides, most late model cars don't require tune-ups until after 100,000 miles or so, its not like cars when we first got our drivers licenses.
With the computer testing features on these engines I suspect it would be simple to run a diagnostic test to get a confident idea of its health, that and a compression/leak-down test should tell the story re a "used" engine. Besides, most late model cars don't require tune-ups until after 100,000 miles or so, its not like cars when we first got our drivers licenses.
You could also do a core exchange for a engine with a longer warranty from several companies that give you the option of flowing the heads and such.....it all depends on what you want to spend...2-5 thousand extra doesnt really seem worth it, but having said that it might be cool to take a normally aspirated 2.5 and with the right inside parts and heads you can get 200 hp out of the same normally aspirated engine.
I'm with Steve- it isn't worth it. The rest of us are driving around in air-cooled engines designed in the 30s, and really essentially unchanged (except to increase power and reduce reliability) since then. 95% of our engines will be fortunate to ever see the back side of 40K mi. Jim Ward is everybody's hero (mine too- go get 'em Jim) for driving his car a couple thousand miles. I've got a '96 Windstar worth about $2500 that I wouldn't hesitate to drive to Alaska, but I get nervous driving further than 50 miles away in my speedster.
A Subaru engine with 25K mi is light years ahead of ANYTHING the rest of us are running. It will easily go another 100-125K mi w/o so much as a plug change or two. I'll see 125K mi in about 350 years at my present rate.
Do I want one? Not really- I'm a retro-grouch, and I want my replica to replicate the original as closely as it can, with a very few modern conveinances. It's aircooled for me, or bust (probably bust).
Do I think John H's car is really cool? Absolutely. I look forward to a full report any day now.
A Subaru engine with 25K mi is light years ahead of ANYTHING the rest of us are running. It will easily go another 100-125K mi w/o so much as a plug change or two. I'll see 125K mi in about 350 years at my present rate.
Do I want one? Not really- I'm a retro-grouch, and I want my replica to replicate the original as closely as it can, with a very few modern conveinances. It's aircooled for me, or bust (probably bust).
Do I think John H's car is really cool? Absolutely. I look forward to a full report any day now.
Me too, but it still isn't finished. Soon, I hope.
jph
jph
John, to me your car makes perfect sense. I would love a dead-realiable water cooled 356 replica. My next convertible has to be a daily driver and that's asking a lot of an air cooled replica. It's not so much the cold up here in B.C., but the rain. If one can get over this 'it has to be air cooled' thing, a Subie powered replica makes all the sense it the world. I'm following your adventure carefully, but unfortunately, I doubt that I would be able to bring a new Subie powered 356 into Canada, or at least at a price that I could afford.
I priced a new IM, with all of the bells and whistles that I think that I'd want (I'm sure I missed a few). finally tally...$47,000 US or.....check the heart monitor....$64,000 Canadian! Mind you, that's the price of a basic Porsche Boxster up here in the land of funny money.
Ron
I priced a new IM, with all of the bells and whistles that I think that I'd want (I'm sure I missed a few). finally tally...$47,000 US or.....check the heart monitor....$64,000 Canadian! Mind you, that's the price of a basic Porsche Boxster up here in the land of funny money.
Ron
Did you ever solve the tire problem? Here are some tire sizes that are at least 24.5 inches in diameter from calculations I did in a spreadsheet. Some may not be available, but the numbers worked out.
Section Ratio Rim Diameter Width
195 65 15 24.98 7.68
175 65 16 24.96 6.89
175 50 18 24.89 6.89
205 55 16 24.88 8.07
225 50 16 24.86 8.86
165 60 17 24.80 6.50
165 75 15 24.74 6.50
225 55 15 24.74 8.86
185 60 16 24.74 7.28
205 60 15 24.69 8.07
195 50 17 24.68 7.68
175 70 15 24.65 6.89
245 50 15 24.65 9.65
175 55 17 24.58 6.89
Section Ratio Rim Diameter Width
195 65 15 24.98 7.68
175 65 16 24.96 6.89
175 50 18 24.89 6.89
205 55 16 24.88 8.07
225 50 16 24.86 8.86
165 60 17 24.80 6.50
165 75 15 24.74 6.50
225 55 15 24.74 8.86
185 60 16 24.74 7.28
205 60 15 24.69 8.07
195 50 17 24.68 7.68
175 70 15 24.65 6.89
245 50 15 24.65 9.65
175 55 17 24.58 6.89
Tires have been selected: BF Goodrich T/A H 185 65 HR15. These have been tested on the car and are looking good and performing well. This model was tested and reported on Tirerack.com with similar tires, including the Potenza, which was an early favorite of mine. The Potenza had a slightly higher rating, but the T/A was the overall favorite if memory serves me.
Steve discovered a problem with the steering rack, a binding. The rack was being replaced yesterday with a fresh one. The Cabrio has over 500 test miles to date. Maybe next week??????
Thanks for your efforts and many calculations.
John H.
Steve discovered a problem with the steering rack, a binding. The rack was being replaced yesterday with a fresh one. The Cabrio has over 500 test miles to date. Maybe next week??????
Thanks for your efforts and many calculations.
John H.
Great news John. I had complete confidence in Steve. I thought there was more to the handling issue than simply tires, glad he found the steering issue and the car will soon be in your driveway.
What I like about Steve's concept is of course the Subaru engine, but also its mid-engine placement will shine, plus real heat, airconditioning, etc., etc., old and new world order
What I like about Steve's concept is of course the Subaru engine, but also its mid-engine placement will shine, plus real heat, airconditioning, etc., etc., old and new world order
Thanks Erik. It even sounds cool, different, but nice throaty sound. I was afraid it would be too quiet, but not so. Believe me, I am anxious to put this baby in my garage but even more to take a drive on a country road.
Steve won't pass it on to me until he is certain everything is OK. I like that. Since my build is approaching the five month mark, it has been a long dry spell without a toy, so the arrival of the Subytub will be doubly welcome. I suspect with the documentation Steve has done during contruction and the things he has resolved, the next build will be shorter. Oh well, it will be worth the wait.
John H.
ps. I'll start a new thread after the car is delivered. This one's getting a little long in the tooth.
Steve won't pass it on to me until he is certain everything is OK. I like that. Since my build is approaching the five month mark, it has been a long dry spell without a toy, so the arrival of the Subytub will be doubly welcome. I suspect with the documentation Steve has done during contruction and the things he has resolved, the next build will be shorter. Oh well, it will be worth the wait.
John H.
ps. I'll start a new thread after the car is delivered. This one's getting a little long in the tooth.
Post 100, ha,ha!!