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70-100 acceleration tests, AGAIN!

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Old 12-31-2002 | 02:39 PM
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Post 70-100 acceleration tests, AGAIN!

We've tried this before, has anybody else done this test? I'm curious to see what other people are doing, please post your car's configuration along with the results. Procedure is the same, roll on from 60, start timer @70, and stop @100mph.

OK, I must've done over 30 tests last night (was out for a long drive out of town). With just me, and about a half tank of gas the car's running repeatable 3.6-3.7s. Highest time I got was 3.8, lowest was 3.5 (I'm using a mechanical stop watch going only to tenths), also factor in about 0.1 seconds for human error +/-. With a ~170lbs passanger in the car, I'm doing a low of 3.7 and a high of 4.0, all tests done last night, I believe it was around 45-50 degrees. I still have a few minor problems but I don't think they would shave over 0.1 secs from the time.

This is running guru chips, relia-boost set to 15lbs (but will go to about 16 in third, likely because of the shimmed wastegate, it'll go to over 20 in 5th), 3 inch open exaust with one open muffler, some headwork, 3bar fpr, and an intake as well as header wrap, wires, plugs and other minor stuff.
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Old 12-31-2002 | 03:08 PM
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You are just running it out in one gear?

We do something similar over on the rx-7 list. It can actually give you a pretty good idea of how your car is running.

-Matt
Old 12-31-2002 | 04:02 PM
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Yes, we do the tests in one gear only which is 3rd. I do agree that this is THE performance test to do. For some reason I can never get a descent respsonse to this test on rennlist...
Ahmet
Old 12-31-2002 | 04:27 PM
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[quote]Originally posted by over1g:
<strong>Yes, we do the tests in one gear only which is 3rd. I do agree that this is THE performance test to do. For some reason I can never get a descent respsonse to this test on rennlist...
Ahmet</strong><hr></blockquote>

I'll try to make a few runs tomorrow. My only mods are Guru Stage 2 Map kit, MBC, Lindsey Bypass Valve, Lindsey wastegate, and Lindsey pump. Exhaust manifold it jethot coated as well.

-Matt
Old 12-31-2002 | 04:33 PM
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Must be spinning some high rpm's to get 100mph in 3rd...this is why I dont like this test.

When I do it, it includes a shift to 4th and I start at 60mph.
Old 12-31-2002 | 05:03 PM
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3rd-gear's good for 115mph so it'll be fine. I was going to do this test two weekends ago with my video camera to time. Plan was to try starting from 10mph below the target and just rev it through in 3rd, 4th, 5th gear to see what the relative times were.

Then I started on a rod-bearing/oil-pan gasket replacement on our test car since it's got 193k-miles (couldn't stand that burnt-oil smell in the cabin anymore). Progress has been slow over the holidays. Should have it all done to test this weekend!
Old 12-31-2002 | 06:19 PM
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3rd gear is good for 115mph if you like 7000rpm+ !!! (7200, 7300rpm looks like a good estimate from the chart).

3rd gear at 100mph puts you at 6500rpm, still too high for my tastes.

This is according to the manual that came with the car, the gearing chart on page 128. With the dropping boost at those rpm levels its not worth revving it that high unless you're at the track (push the extra revs to be able to hold the gear through the turn...something of that nature).

Yes at autox I've taken the car to 6600, 6800rpm in 1st or 2nd, but its not something I'm about to do over and over and over and over again.
Old 12-31-2002 | 06:44 PM
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There's something wrong with the info you're posting. What's the stock redline on a 944 isn't it around 6425 or thereabouts? Stock redline with stock gearing on a 944 turbo you will be doing around 116 @ redline. 100mph in 3rd is no big deal. I think you're thinking of the normally aspirated 2.5 liter 8 valve cars. I can't believe you're scared of revving your car to 6k regardless though, what do you normally shift at 4k? Stretch the legs of that nice turbo S you got!
Ahmet
Old 12-31-2002 | 06:55 PM
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Well, redline in 3rd in my car is just above 85, 4th is 115. If i remember correctly. The real mph is probaly alittle higher, those are just the points i use as max downshift points. Either way, something is wierd. Does the Turbo S have a different gear box than a regualar turbo? I've never heard of that before... <img src="graemlins/c.gif" border="0" alt="[ouch]" />
Old 12-31-2002 | 07:01 PM
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It's been a while since I had my non turbo 944, the gearing's that different? All turbos use the same gearing, I think there's still something wrong with the info adrial's posting though. At the redline I had for about a year (around 7200) 2nd topped out @ something like 72mph? My NA topped second @ 58, indictaed 61mph or so, I do remember that clearly cause I hit it very often!
Ahmet
Old 12-31-2002 | 07:36 PM
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Yup, I just ran out to the car to grab the owner's manual. Using appox 6500rpm as the redline, the transmission diagram shows speeds of:

1st: ~37
2nd: ~58
3rd: ~83
4th: ~115
5th: ~165

So in an NA you'd either have to start in 3rd and shift, or start in 4th at about 4000(which is 70mph).

This still doesn't clear up what Adrial is saying, maybe he's looking at the km/h ?
Old 12-31-2002 | 07:54 PM
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[quote]Originally posted by over1g:
<strong>All turbos use the same gearing, I think there's still something wrong with the info adrial's posting though.</strong><hr></blockquote>
Nope, my 3rd tops out at 100 mph as well [6500 RPM].
Old 12-31-2002 | 08:02 PM
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I just took my car out, 100mph comes at 6krpm, and redline (approx. 6450) is around 118mph indicated. Stock size tires, stock gearing 86 turbo...
Ahmet
Old 12-31-2002 | 08:49 PM
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I hit 100 at about 6000 rpm's in third. I don't know why, but I'm starting to like 4th gear better than third. When I get to about 4-5 K, it's a total rush. Sorry to get a little off topic. What's the gearing for fourth? 140?
Old 12-31-2002 | 08:56 PM
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my owners manual on the transmission diagram shows top of 3rd for the na at about 85 mph, the s shows about v88 mph and the turbo about 102 mph. i'll have to do this test thing now and see what i get. later tonite thou.


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