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The issue of Autombile Magazine that has the Bugatti Veyron points out that only 266 HP is required to reach 155 MPH. Then it says that when you summon the remaining 721 HP, all hell breaks loose. It's actually got a gauge that shows the HP being generated. Pretty cool car - 1,000 HP and 250 MPH. And the neat part is that it was designed for these speeds. So it's got the brakes and the aerodynamics not to cause problems when you're driving it. The guy said that he'd done 212 MPH on the AutBahn and that the 100 MPH differential completely freaked out he other drivers. LOL. I guess so!
 

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I have a freind her in the Iowa area who has a black 83 or so mk.2 supra that has been built to run in the stock class of the salt flat racing. Not sure what the requirments are you have to meet but he dropped efi added webbers and higher comp. pistons. He says they clocked him @ 127 mph in the timed run....... but i've hit a speedo read of 130+ on bfgs 245/50 in about a mile? pushing around 6000 rpms on a stock 5m.. sound right?
 

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Most factory speedos are not all that accurate, and strangely ;) they usually indicate faster than reality. I also heard that this error is on purpose.
 

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Yeah i would agree that the speedos in all the mk.2s i have driven seem to be off by a margin of 5 mph... thats with both the factory 235/60/14s and my 245/50/14s. All in all it kinda sucks to be driving on the interstate at a speedo read of 65mph and you see a old lady pass you slightly faster..... :bananas: :mm_gay:....
 

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Lee_MA61 said:
Yeah i would agree that the speedos in all the mk.2s i have driven seem to be off by a margin of 5 mph... thats with both the factory 235/60/14s and my 245/50/14s. All in all it kinda sucks to be driving on the interstate at a speedo read of 65mph and you see a old lady pass you slightly faster..... :bananas: :mm_gay:....
you mean 225 right? doing the math between the p-type and the l-type tires from 83 era and noticed that the p-type tirs are slightly smaller than the l-type. this could throw any speedo off. :)
 

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scorpmatt said:
you mean 225 right? doing the math between the p-type and the l-type tires from 83 era and noticed that the p-type tirs are slightly smaller than the l-type. this could throw any speedo off. :)

Yeah thats what ment lol.... i'm just going to have to fly by a trooper at my top "speedo" speed and see if what s/he says matches up..lol
 

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I have done 235 km/h when I had my 5mge in there... I was running a rabid chimp intake and 2 1/4" exhaust... regular cat... 235km/h is 146 mph... it may be a bit inaccurate but I believe that was the speed I was going.. I calculated it from my rpm... I don't have my speedo in front of me so I don't remember the increments off hand but it worked out decently and I tested it with friends cars (much higher speedo's) considering mine does 140 km/h tops.... :S
 

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kmfdmk said:
85 Celica Supra w/ original 5M-GE
-Bosch Platium 2's
-K&N Air Filter
-5-speed
-225 60R14s

Tops @ 128mph, because the engine will not rev past about 5700rpm while in 5th. However I had prolly 200 lbs. of extra crap in the car. So I figure if it was lighter she'd go faster.
About 3 years ago I have done 6350rpm with (96%) stock 5M-GE in 5:th gear. My car had then 4,3 differential and 235/60/14 tires. We calculated that it was goin 140mph (true...not spedo mph) but only thing that i`m sure is revs.
 

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chrisfromda909 said:
205/60/14's
I bet your car doesn't even move with 205's on it. My 225's would spin indefinitely before I upped to 235s, so I can't imagine using 205's.
 

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For all you people who have no idea about what speed you are going, ask your friends if they have a GPS receiver that calculates instantaneous velocity. My dad has one that updates speed every 1/10th of a second, very useful for when he changed his tire diameter, we were able to measure the difference so that he always knew to add 4 mph to his speedo reading.

Most GPS now come with this function. I have a program on my computer that uses GPS data to calculate speed by v=d/t. I think there are more sophisticated proggies on the internet that will use GPS data to calc your acceleration, approximate horsepower and torque, quarter-mile, etc. just by knowing your GPS loc, the time, and your car's weight.

And I am with chris on this one, you should be able to control your car's torque output regardless of tire width. Changing from 225 to 235 would only increase the 'footprint' area of the tire on the road by 8%. I doubt that kind of increase would produce the difference between spinning and not-spinning. Also, surface area has less to do with static friction, the main factors are force (weight) and the co-efficient of friction between the two compounds.

And Chris, the chart is for 225/60/r14. Because you have 205/60/r14, the side wall is just a bit shorter than the 225's. This makes the effective diameter from the center of the hub to the tread a centimeter or two shorter. If you look at the chart for a 4.10:1 diff, at 4500 rpm's with a 225/60, it should go 97 mph? (the chart graphic won't download while I am typing this). And your 205's will have slightly less diameter, so I would say you have a 4.10 diff because you are making 94 mph on the smaller tires.
 

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JoeBWanKenobi said:
And I am with chris on this one, you should be able to control your car's torque output regardless of tire width. Changing from 225 to 235 would only increase the 'footprint' area of the tire on the road by 8%. I doubt that kind of increase would produce the difference between spinning and not-spinning. Also, surface area has less to do with static friction, the main factors are force (weight) and the co-efficient of friction between the two compounds.

And Chris, the chart is for 225/60/r14. Because you have 205/60/r14, the side wall is just a bit shorter than the 225's. This makes the effective diameter from the center of the hub to the tread a centimeter or two shorter. If you look at the chart for a 4.10:1 diff, at 4500 rpm's with a 225/60, it should go 97 mph? (the chart graphic won't download while I am typing this). And your 205's will have slightly less diameter, so I would say you have a 4.10 diff because you are making 94 mph on the smaller tires.
Someone who knows what the hell they are talking about. Thanks Joe, the only reason I couldnt figure it out is because the chart would not download.
 

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chrisfromda909 said:
WTF are you talking about.
All I was saying is that 205s are pretty skinny. And when I had my 225s I could make them spin for a LONG time. I can't even imagine how long someone could keep 205s spinning. I wasn't saying your car lacked power, just the opposite. With tires that skinny, it would be hard to not spin them. I didn't think my post would be that hard to decipher.:rolleyes:
 

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these are the tools i always use for tire/gearing changes.

this one will give you the diameter. *note, not all manufacturers tires are the same diameter for the same wheel. Meaning, not all 225/60R14's are the same diameter from all manufacturers. This will give you what it SHOULD be based on the numbers though.
http://www.bigcustomwheels.com/info_specs.jsp


then i use it with this site to figure out the speeds and such. quite useful for checking new rear end ratios, tire diameter changes, and tranny changes. *note, some manufacturers sites have the diameter information already, so using that info instead of the tire size calculators info will give you a more accurate reading with this site.
http://www.csgnetwork.com/rearendgearcalc.html
 

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chrisfromda909 said:
Mone, I see what your saying now. Ive never drievn on 225's, but I could imagine that they wouldnt spin for that long. I used to get side ways on the 205's, I dont imagine it would be so easy with 225's and my lack of power.
You do have one advantage with 205s, CHEAPER. But you better believe you can make those tires squeal, even with a stock 5m (I got my 6m almost immediately, but the gain in torque isn't too drastic). Dropping the clutch at 5500 or so would make the 225s sqeal for around 4 seconds before I would shift out of 1st, and if I put the brake on after it got started, I could spin them til they popped. Nothing like doing a donut that takes 10 seconds per revolution. :facesjump
 

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I've topped out just over 140 in my 85 with a 5mge. I had 225's on the front and 265/60/14's on the rear though. Those are quite beefy. I didnt seem to have any problems getting to 6500rpm in 5th and mine is bone stock. If you are, try accelerating a little at a time instead of just flooring it. I had plenty of room and time out in BFE Wyoming. Was pretty funny passing that 5.0 Mustang going that fast. He finally caught up to me though....after I exited the interstate.
 
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