What happened to my non-linear spool up at 3500 RPM?
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Back in the days of old, somewhere around 4000 miles, I began noticing a smoothing out to my power curve around the 3500 RPM range. Before that time, there was a very definately non-linear curve that my back felt as I was pushed into my seat. Now at 6000 miles that zest and zing is no longer there. From 600 through on up it feels like a straight line. To be truthful, there is a small knee still around 3500 RPM. Is this normal? Am I now used to the car? Or am I loosing some of my "271 pissed off horses" (from the dealer's flyer)?
I've been careful to observe the fact that you want to let the turbo cool down before shutting the engine off (sorry, no turbo timer installed yet, sound first LOL). I still have that audiable sssswwwwooooosssshhhhiiii <insert turbo spool up sound here> from 3500 to 4500, but its a gentle knee now, unlike the sickness I once felt.
The techs and service manager at the dealership are afraid to drive the EVO's for the sole reason that there is so much social responsibility that comes with driving a car like this (like stripping off the paint of cars you pass, let alone getting a speeding ticket).
Is this normal? Is there something I can prove? Thoughts?
Thank you.
I've been careful to observe the fact that you want to let the turbo cool down before shutting the engine off (sorry, no turbo timer installed yet, sound first LOL). I still have that audiable sssswwwwooooosssshhhhiiii <insert turbo spool up sound here> from 3500 to 4500, but its a gentle knee now, unlike the sickness I once felt.
The techs and service manager at the dealership are afraid to drive the EVO's for the sole reason that there is so much social responsibility that comes with driving a car like this (like stripping off the paint of cars you pass, let alone getting a speeding ticket).
Is this normal? Is there something I can prove? Thoughts?
Thank you.
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get out onto a smooth level highway and videotape (or otherwise record measurements from) your tachometer during a roll from 2000rpm in 3rd or 4th gear. afterward, playback the video and see how much the rpm's are increasing at regular intervals (e.g. sampling once per second). then get some graph paper and plot time on the horizontal axis and RPM on the vertical axis. the idea is to use the delta in RPM as a proxy for average torque delivered to the wheels over that time period.
obviously this is a pretty rough method but it should become pretty obvious if you are not seeing exponential torque increase once your turbo spools!
the butt-dyno can be deceiving!
obviously this is a pretty rough method but it should become pretty obvious if you are not seeing exponential torque increase once your turbo spools!
the butt-dyno can be deceiving!
Last edited by ez76; Jun 21, 2004 at 10:07 PM.
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Originally Posted by Jonasan50
Sounds to me that you are used to the power... Clear signs to start modding... Enjoy!! You don't know what you're missing!!
What he said. Boost controller, turbo back, to start you of with . then it starts getting addictive . cams , intercooler, turbo kit..ect its endless. ME Want MORRRRREEE!!!!
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That's the problem. I'm unsure of the formula used to perform the required calculation:
income - (exhaust + turbo + gauge + stereo + ...) *(1- 0.8 fun) - NSF + lunch_rides * (n - 1)
...uhhh, where's those credit card offers......
income - (exhaust + turbo + gauge + stereo + ...) *(1- 0.8 fun) - NSF + lunch_rides * (n - 1)
...uhhh, where's those credit card offers......
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lol it happens to the best of us....all it means its time to unleash the beasts real power and modd the hell out it......it will take awhile longer for your butt dyno to adjust......or the second way is you can lay off the boost for about a week so your not used to it anymore....lol i did that when my cash flow was a little low....
Just my .02 cents
Just my .02 cents
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What do I do if my dealer can't perform a "boost leak compression check"? Its in the shop now and they say they can't do this test. So they take it for a test drive instead and insist there is no problem? Not even when the steering wheel shudders when I lightly tap on the brakes at 65MPH do they find a problem with it. Is this shuddering normal? I think not because it is a new occurance.
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Originally Posted by tcollins
What do I do if my dealer can't perform a "boost leak compression check"? Its in the shop now and they say they can't do this test. So they take it for a test drive instead and insist there is no problem? Not even when the steering wheel shudders when I lightly tap on the brakes at 65MPH do they find a problem with it. Is this shuddering normal? I think not because it is a new occurance.
Pressure testing the intake tract is the most effective means of finding a boost leak aside from a trial and error process of tightening clamps. Pressure testing involves about $15 worth of miscellaneous plumbing supplies and an air compressor.
As far as you warped rotors are concerned, I guess you can join the club with the other guys who have the same problem. It's usually caused by brake pad transfer or the rotors themselves are actually warped either by rapid cooling or improper torquing of the lug nuts. Your dealer should be able to check the rotor surface for axial runout. If you've got any, you'll have a shudder or shimmy when applying the brakes. If you don't have any runout, then you're prolly suffering from pad transfer which can be sanded off the rotor surface.
Good luck.
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No boost is measured yet by myself, nor by the dealer apparently. I went under the assumption that if the dealer sells it, they can troubleshoot/fix it. The $15 is cheap, but I still need to find me an appartment-friendly air compressor...
I gotta get me a boost gage. Any recommendations?
I gotta get me a boost gage. Any recommendations?