Morison Banned Junior Moderator Location: Calgary, AB Join Date: 03/27/2009 Age: Ancient Posts: 1,798 Rally Car: (ex)86 RX-7(built), (ex)2.5RS (bought) |
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john vanlandingham John Vanlandingham Professional Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Oh, really. We had already established that years ago but thanks for talking about TSD ODOs that you've used... Dave, for the clock, having it IN the odo will add an extra $90-120 PLUS dollars. Velco a Drug Store stop watch to dash for $12. There are reasons many complain about cost: they're actually bragging. |
NoCoast Grant Hughes Ultra Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
Or wear a watch that you bought that day at Wal Mart like I always end up doing. I'm a firm believer in the cheapest odo being the best odo. I've yet to see an argument worth a few hundred dollars. |
DaveK Dave Kern Junior Moderator Location: Centennial Join Date: 07/11/2008 Age: Midlife Crisis Posts: 1,085 Rally Car: Compact M3 & Evo IX |
So the "new" rear suspenders arrived today.
Looked at the box and said shit...where's the other box, well, maybe both fit in there just barely. Picked up the box and said shit...too light, no way there's two in here. Opened the box and to my surprise there were two shocks in there. Them's some lightweight parts John! Dave |
john vanlandingham John Vanlandingham Professional Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Magnesium bodies straight of the back of Stig Blomqvists' last GpA Escort Cosworth left over when they changed it to World Rally Car spec in '97. Mats Jonsson who bought it way back still uses it, and in fact was out in the National portion of Swedish WRC setting times better than all but the top 4.. The water cooled mates to those are on the back of my 4x4 thing |
Morison Banned Junior Moderator Location: Calgary, AB Join Date: 03/27/2009 Age: Ancient Posts: 1,798 Rally Car: (ex)86 RX-7(built), (ex)2.5RS (bought) |
John, I wasn't talking about TSD odos. My point was that buying an odo that does JUST distance and speed is a waste of money for the majority of events in North America. This is particularly the case if you can keep the factory speedo and odometer. An odo you can calibrate is a nice touch, for sure, but it really is a luxury running on notes. Grant, I've long since learned that the only time 'cheap is best' is when you assume the item is a throw-away item and quality/durability isn't a factor. Spending good money on quality parts is usually cheaper in the long run. And if that $90-120 PLUS only duplicated the functionality of a drug store stop watch velcro'd to the dash, you'd have a point. But you don't. I have to assume that was meant for the Warmbold thread otherwise that was a real non-sequitor John, even for you. I was neither complaining nor bragging about anything. I was merely correcting misinformation about the Lazer3 and giving some perspective on it as I have owned and used one extensively. I guess the first question to ask is 'why buy and install an odo in the first place' followed by 'what do I want out of an odo.' With those questions answered you can judge value vs. price. |
john vanlandingham John Vanlandingham Professional Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Is your odo or trip in the dash unaffected by changes in tire diameter? Is it unaffected by changes in final drive? Curious, not arguing. Dave has now 4.56 final drive, he HAD gawd knows what. 3.2? 3.3? Thats a shit ton shorter, or more revolutions per mile by 30% or more He HAD whatever for tire diameter. Now he has 64/65cm tall, there's 8-9% LESS revolutions per mile.. Do modern OEM in car odos compensate? Does Mark's in the BMW? |
BillyElliot Billy Elliot Mann Senior Moderator Location: Royal Oak, MI Join Date: 08/11/2008 Age: Midlife Crisis Posts: 557 Rally Car: 1996 Honda Civic with VTEC YO! |
Not changed by final drive since the speedo reads directly from the diff rotation. Tire diameter yeah, that's a no brainer. Gravel tires and snow tires are the same diameter, tarmac tires are 1.7% less. From doing transits that equals a tenth under for every ten miles, which isn't really a problem. |
NoCoast Grant Hughes Ultra Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
Yeah. I'd agree with that statement. But Odos are a convenience. I've codriven more events without an odo than with. Driving at Colorado I didn't have speedo or odo in the car at all. Then again, I'd codriven there once so knew all the routes already. Filming has helped too since I basically have to find all the stages, determine the likely transit routes, and devise our own little TSD to get around. Dave's back onto a 4.3 diff. I think he said a bearing in the 4.56 diff gave during the first day of testing. Pinion bearing I recall... |
john vanlandingham John Vanlandingham Professional Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Oh, really? My snows are 65cm, my gravel tires are 62cm, and I have no tarmac but if I did they would be 58-59cm. 62 to 65 is 5%. 58 to 65 is 12% And the diff rotates just a scance more revolution per mile when the ratio has changed from say 4.88 to 5.45---there's 12% more diff rotations per mile. Seems like a range of 17 to 24% depending. That said, I kinda like errors under .01/mile on stages. Whatever. ![]() |
BillyElliot Billy Elliot Mann Senior Moderator Location: Royal Oak, MI Join Date: 08/11/2008 Age: Midlife Crisis Posts: 557 Rally Car: 1996 Honda Civic with VTEC YO! |
Well that's why it's nice my speedo is driven off the diff directly so it's measuring actual wheel speed. If I remember right when I had my VW and was looking into a final drive, you got some gear that drives off the gears before the diff, so when you change the final you need to put in a different speedo gear? On a RWD car, the diff will be a big thing since it's in the rear isn't it (I don't know exactly since I don't play with RWD cars now). But if I'm getting .1 error for every 10 miles that comes to .01 per mile, so it looks like I'm within your tolerance! |
NoCoast Grant Hughes Ultra Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
Our poorly placed sensor at 100AW resulted in picking nothing up under braking so our error ranged from no error if there was no hard braking to miles short if there was alot of braking.
One friend used a bike odo with great success. Dave. Isn't there like some $5000 ECU you could get that would handle all of this for you? ![]() |
DaveK Dave Kern Junior Moderator Location: Centennial Join Date: 07/11/2008 Age: Midlife Crisis Posts: 1,085 Rally Car: Compact M3 & Evo IX |
My problem is the BMW OEM setup uses a sensor in the rear diff. The Supra must use a sensor elsewhere (gearbox maybe?), as there's nothing in the diff. So, for now I've got no readings at all in the car. Headed to the shop after work. Gotta drop those new suspenders in the car and take another stab at door panels. Thinking if I can load the car on the trailer tonight & back it into the shop it'll make for a quick getaway Saturday morning....big question is if CORE will be a mudfest...not going thru that again!! No aftermarket ECUs for this car - OBD-I is nice like that. Have considered going to a more tunable/adjustable chip when/if the belt powered snail makes it into the car. Ahhh, the beauty of a 3.0L. ![]() Dave |
Morison Banned Junior Moderator Location: Calgary, AB Join Date: 03/27/2009 Age: Ancient Posts: 1,798 Rally Car: (ex)86 RX-7(built), (ex)2.5RS (bought) |
Why? You'll see more error than that with wheel spin/slip or differences in driving line even if you take your odo feed off of a non-driven wheel. Passing a hard point with less than 1% error, less than 18 yards per mile, on a stage, might make you feel good but it does NOTHING else for your performance. 18 yards will tell you for sure if it is one corner or the next. Why are you looking at your odo on-stage anyway? Still running tulips? In that case I'd agree a rally odo becomes MUCH more important but on notes you don't really need one on stage. (particularly with recce) If you're on tulips, surely you're using an interval odo to go from element to element and not relying on the cumulative odo (because of wheel spin/slip error.) I've rarely seen tulip books with less than two or three instructions per mile, so you're looking for tighter tolerances than the routebook given to you. At an average speed of, say, 50 miles per hour you're looking at a difference under 3/4 of a second per mile. With 3 instructions per mile, that's an accuracy of 1/4 second per instruction (on average.) The accuracy of resetting exactly where the routebook author resets the interval starts coming into play then. THEN... remember that tulips aren't accurate enough for split second commitment to a call and you'll see that there is no reasonable reason to look for .01/mile accuracy on STAGE. (TSD is another story all together.) I've also done more events without an odo in the car than with including doing brand-new to the team events in the US with a car running a odo in Km. Even if your stock odo doesn't handle the diff/tire changes you'll have a consistent error and you'll know what that factor is. Easy to deal with. Like I've heard said before - if you're going to buy something make sure you know what you what it to do before you make your buying decision. If you're not sure what you want out of an odo either ask your co-driver or ask someone who can help you figure it out. Since the purchase will become your primary odo/speedo on the car I think you'd want something that would be reliable. You might want to look at what Alpha has to offer. The Alpha Pro is probably the right point to be at. http://www.rally.cc/#ProStart The Club/Ecomony I've seen in action and it wasn't very pretty. The beauty of the Alphas, if you're the flag waving type, is they are made in the USA. (The site says they are out of production but email him and find out what the deal is) Edited 1 time(s). Last edit at 04/14/2011 01:08PM by Morison. |
DaveK Dave Kern Junior Moderator Location: Centennial Join Date: 07/11/2008 Age: Midlife Crisis Posts: 1,085 Rally Car: Compact M3 & Evo IX |
My background is in hillclimbs where we have been writing our own notes for 5-6 years.
Don't really have any plans to run hardcore TSD style events. We plan to run rallies with notes and/or recce...probably wouldn't consider an event if they don't offer at least one of those choices. Don't need to start a discussion on the virtues/evils of recce, its what WE know and like. Thinking that in an ideal world I'd hook up the factory ODO to the drive wheels and hook up the rally ODO to the fronts if that's doable. Dave |