Ian C Posted June 13, 2003 Share Posted June 13, 2003 Right, first a bit of background, I've got an Apexi Shiny Thing that gives me a few readouts (speed, revs, boost pressure etc) and a peak hold function. It's more accurate than the dials on the dash. I've got a TT 6 speed. Now, while performing the worst launch I've ever done at traffic lights yesterday, I hit a limiter of sorts in 1st gear. The Apexi unit showed a peak rpm of just under 6500. Peak boost was 1.1 bar. I know that previously I have had a limiter in 1st gear kick in at 6700rpm as well. In fact, I've never got past 6700 in 1st, this limiter always kicks in (I usually reach this engine speed due to losing traction), and the boost pressure never gets near what I normally get in other gears as there just isn't the load or the time to acheive it. Now, the interesting thing is that I've hit a 7090rpm peak at Santa Pod in 4th gear. No limiter cut in. 1.3x bar of boost peak. I've gotten over 6700rpm a good few times without a limiter cutting in. So it's not a fixed rev limiter and it's not fuel cut, so wtf is going on? Anyone else experience this? -Ian Link to comment Share on other sites More sharing options...
Doughie Posted June 13, 2003 Share Posted June 13, 2003 Originally posted by Ian C Right, first a bit of background, I've got an Apexi Shiny Thing that gives me a few readouts (speed, revs, boost pressure etc) and a peak hold function. It's more accurate than the dials on the dash. I've got a TT 6 speed. Now, while performing the worst launch I've ever done at traffic lights yesterday, I hit a limiter of sorts in 1st gear. The Apexi unit showed a peak rpm of just under 6500. Peak boost was 1.1 bar. I know that previously I have had a limiter in 1st gear kick in at 6700rpm as well. In fact, I've never got past 6700 in 1st, this limiter always kicks in (I usually reach this engine speed due to losing traction), and the boost pressure never gets near what I normally get in other gears as there just isn't the load or the time to acheive it. Now, the interesting thing is that I've hit a 7090rpm peak at Santa Pod in 4th gear. No limiter cut in. 1.3x bar of boost peak. I've gotten over 6700rpm a good few times without a limiter cutting in. So it's not a fixed rev limiter and it's not fuel cut, so wtf is going on? Anyone else experience this? -Ian Are you certain that the "Apexi Shiny Thing " is 100% accurately recording rpm ? how is it doing this ? Using telemetry on a kart, it records rpm by clamping a "crocodile clip" to one of the HT leads and it counts each HT-voltage spike that goes thru that HT lead. this of course easily gives rpm 100% accurately. it might be that A.P.T. is using some other "guesstimate" for rpm. what sensors does it use ?? Link to comment Share on other sites More sharing options...
Ian C Posted June 13, 2003 Author Share Posted June 13, 2003 It intercepts the rpm signal going to the ECU, so it's going to be as accurate as the ECU's rpm values. -Ian Link to comment Share on other sites More sharing options...
400BHP Posted June 13, 2003 Share Posted June 13, 2003 An inductive pick-up (the crocodile clip) is not 100% accurate simply by definition, the most accurate way of RPM is a crank position sensor, which is what the ecu uses. Link to comment Share on other sites More sharing options...
Matt Harwood Posted June 14, 2003 Share Posted June 14, 2003 I don't seem to have a rev limiter at all Link to comment Share on other sites More sharing options...
Guest Usmann A Posted June 15, 2003 Share Posted June 15, 2003 Same here no limiter, me dad revved it into the 7500K once by mistake, one first day of purchase..... Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now