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    Results 1 to 11 of 11
    1. #1
      Join Date
      Oct 2006
      Location
      Las Vegas, NV
      Posts
      226
      Country Flag: United States

      Turning higher RPM's with TKO 600....

      I recently installed my new TKO 600RR (.82) into my 69 camaro. I have a 3.42 posi with 275x40x18's. According to the RPM calculator I should have been turning 2299 rpms at 65 mph. Now I realize the calcualtors aren't 100% accurate but they should be relatively close. My road test today at 65 showed I was turning 2750 rpms. That's 450 rpms more than I thought I was going to be turning over. Anybody else turning different rpms than expected after doing a TKO swap?



    2. #2
      Join Date
      Aug 2005
      Location
      Patterson, NY
      Posts
      784
      Are you sure the speedometer is correct?
      Jason Scheer

    3. #3
      Join Date
      Nov 2004
      Posts
      105
      sounds like you have it set on the .64 not the .82 on you computer.

    4. #4
      Join Date
      Feb 2007
      Location
      USA, TN
      Posts
      850
      Who's RPM Calculator? That RPM is close to 4th gear.

    5. #5
      Join Date
      Oct 2006
      Location
      Las Vegas, NV
      Posts
      226
      Country Flag: United States
      I am going to take my GPS out tomorrow just to make sure my speedometer is correct. When I bought the tko kit it came with the correct speedo gear (black in color) for a 3.42 rearend. So hopefully it will be the speedometer itself that's wrong. Gives me good reason to buy my new dash with gauges that I've been wanting.

      The RPM calculator I used was from the classic chevy 5 speed and the kiesler websites.

    6. #6
      Join Date
      Aug 2005
      Location
      Patterson, NY
      Posts
      784
      I don't know if you took into account the height difference between the stock tires for your car and the current ones. Those are almost an inch taller than the stockers, IIRC.
      Jason Scheer

    7. #7
      Join Date
      Oct 2006
      Location
      Las Vegas, NV
      Posts
      226
      Country Flag: United States
      Yes I did. When you use the RPM calculator it asks for the complete tire size, i.e. 275x40x18. I'm going to take it out tomorrow and do some tests and I'll post my results.

    8. #8
      Join Date
      Oct 2004
      Location
      IL/TN
      Posts
      909
      Country Flag: United States
      how about doing the math?, the formula is 336 X final drive X mph / tire diameter = RPM.
      So in your case it's 336 X 2.8 X 65 / 26.6 = 2298.9 rpm, I would conclude that your speedo is off ;)
      https://www.protouringf-body.com "doing what they say can't be done"

    9. #9
      Join Date
      Oct 2006
      Location
      Las Vegas, NV
      Posts
      226
      Country Flag: United States
      Well you guys were right. After doing a road test with the GPS my speedo is wrong. Here are some of the results:

      At 35 mph on my speedo, I was actually doing 42 mph.
      At 65 mph on my speedo, I was actually doing 77 mph.

      Now I know the GPS is accurate because I have used it in three different vehicles. I'll be calling amp performance tomorrow to get a new speedo gear for it. To give you an idea of the rpms though, at 80 mph I was around 2800 rpm. Pretty happy with that. Thanks for all the help and suggestions.

    10. #10
      Join Date
      Jul 2005
      Location
      Kingsport, TN. 30 min. from Bristol and 90 min. from Pigeon Forge, TN.
      Posts
      220
      Country Flag: United States
      I think the 3:42 gears I've used in the past required a yellow speedo gear.

      It will differ on your tire size. I would call them to check and see if you have the right gear.

    11. #11
      Join Date
      Oct 2006
      Location
      Las Vegas, NV
      Posts
      226
      Country Flag: United States
      Just an update. I talked to AMP Performance and they told me they screwed up. They sent me a black gear when they should have given me the pink gear. I believe he said the black one has 22 teeth and the pink one has 19 teeth. They are sending out a yellow one as well just to be sure.

      I don't know if any of you ever dealt with AMP Performance out of Phoenix, AZ but they are very good to deal with. I've had two problems that they have rectified immediately and the customer service is outstanding. I highly recommend these guys.





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