4000rpm in 6th what speed to you get?
08-10-2008, 05:49 AM
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4000rpm in 6th what speed to you get?
Before I had my engine replaced,
with my winter tires (17's) at 4000rpm in 6th I was at a speed saying
134-137km/hr
With my stock 18's I was
130km/hr dead on
Got my new motor in today and Im at
120km/hr dead on
WHY???? That dosnt sound correct to me?
I understand the diff. from 17" to 18" rims
but just changing the engine???
with my winter tires (17's) at 4000rpm in 6th I was at a speed saying
134-137km/hr
With my stock 18's I was
130km/hr dead on
Got my new motor in today and Im at
120km/hr dead on
WHY???? That dosnt sound correct to me?
I understand the diff. from 17" to 18" rims
but just changing the engine???
08-10-2008, 01:45 PM
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Wheel size would not likely have too big of a difference because smaller rims typically run thicker tires. ~135 is proper, thats about 80mph. This is what you should be at, perhaps you looked at it wrong? Shot in the sky but check your invoice and see exactly what they did. Then again, I can't see anything changing that factor, its all in the gearing nothing motor.
08-10-2008, 01:52 PM
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Well that's why I asked the question because to me it does not make sence
My 17's to 18's makes sence because both sets are 45's so there the 17s are a bit smaller.
I document everything about my car in a booklet I keep, So I know exactly what rpm's I was running at, mainly because I use this pretty much on highway only.
I'll let the engine break in, but I just dont see it making a difference, I was thinking there might be something different about it or something, but shouldnt it only have to do with the gears of the transmission?
My car is running so far really really nice, its so much smoother just seems a little higher rpm to maintain the same speed. Thought it was interesting
My 17's to 18's makes sence because both sets are 45's so there the 17s are a bit smaller.
I document everything about my car in a booklet I keep, So I know exactly what rpm's I was running at, mainly because I use this pretty much on highway only.
I'll let the engine break in, but I just dont see it making a difference, I was thinking there might be something different about it or something, but shouldnt it only have to do with the gears of the transmission?
My car is running so far really really nice, its so much smoother just seems a little higher rpm to maintain the same speed. Thought it was interesting
08-11-2008, 02:08 AM
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Would a sensor foul-up cause this problem? Perhaps the readout is wrong. I'm not familiar with the rx8 wiring so I can't say for sure. Maybe try to find out how fast you are actually going, have a friend drive alongside you or something
Also, tires will change diameters although you shouldn't be seeing anywhere near that kind of dispairity.
Also, tires will change diameters although you shouldn't be seeing anywhere near that kind of dispairity.
08-11-2008, 02:45 AM
#10
the reading on your speedo is not influenced by tyre size - the ECU is programed for the stock tyre size .
Actual speed at a set rpm will differ with different tyre sizes but not the speedo readout ......
could be something up with the rpm pickup .....
Actual speed at a set rpm will differ with different tyre sizes but not the speedo readout ......
could be something up with the rpm pickup .....
Last edited by Brettus; 08-11-2008 at 02:51 AM.
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