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3.4 5 Speed Video


99RegalGS
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I had heard the 1st gen grand prixs had a really good drag coefficient. Do you have a source for that .34 for the cutlass (or lumina, whatever you are talking about).

 

I have an old (circa 1988) Cutlass ad that says the Cutlass drag coefficient is .297.

 

considering that cutty is 16 y/o i'd say that's pretty good.

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To bad 0.297 is wrong.....remember.....C5 Coupes have the best C/D of the lot at 0.29 (Z06 at 0.31 and Convertible at 0.33).

 

The funny thing is, outside of the Vette's, *Beretta's* have the best C.D. of any USDM GM car (a few European Opel's such as the Calibra are a whole lot better though :D ).

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To bad 0.297 is wrong.....remember.....C5 Coupes have the best C/D of the lot at 0.29 (Z06 at 0.31 and Convertible at 0.33).

 

How is it wrong? Maybe there's more to aerodynamics than a low-slung body. The original 1986 Mercury Sable was measured at 0.29 also.

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The styling was dull, performance anemic, it was noisy, and handling was barely passable for a car with sporting pretensions - despite the '89 version having a coefficient of drag (Cd.) measured at a very slick 0.29.

 

http://www.canadiandriver.com/articles/jc/88-96grandprix.htm

 

 

I also remember reading in a hardcover book that the '88 GP had the best drag coefficient (compared to what, I'm not sure). This is the reason I was able to get my ~130hp, non-tuned 2.8 up to about 110mph. It was redlining in 3rd until the engine shut down. Gimmie a 5-speed and I'm sure I could hit close to 200km/h, cause it was the gutlass engine not the aerodynamics of my "slick" car.. lol

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the run is up to 100mph...i did not drop the shifter to 2nd as you will see 2nd shifts out into 3rd at about 6200rpm's...

 

My question is why if I thuoght the FFP chip raised the shift points.

 

At the beginning I stalled to about 2K then dropped it...you can see the 1sec lag as the RPMS rise out of 2-3K.

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Wow that sounds sooo much different than mine. God I NEED A CAMERA!!!!

How so? I'm sure you know someone who has a camera. I want to hear yours now.

 

Well when Aaron drag races his car you hear a meat grinder sound between the shifts!! :lol: I'm just kidding Aaron!! Don't get your manties in a wad!! :wink:

 

Maybe idBeast still has the video of our racing Aaron and you can hear your intake very clear in that! Along with the grinding sound! 8)

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what kind of complaints? I would venture that maybe gas milage??

 

 

so shift points are MPH based? Good to know, I thought they were RPM based. Either way, what would good shift points be other than stock?

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For some reason I can't download your video (it hits 21% and freezes), but you'll have to figure out (preferably with a scan tool) what speeds correlate to what rpm for YOUR car...........the LQ1 auto's just seem to vary too much overall (rpm vs speed) from car to car.

 

I would probably shoot for something like 6500rpm for 1-2, 6250rpm 2-3, and 6000rpm for 3-4 (if you leave the selector in "D").

 

This is to keep the tranny happy, as it isn't rated for more than 6500rpm off of ANY shift's (GM says the 60/65 series tranny's are good for 6500 1-2, 6250 2-3 and 6k 3-4), and the enigne happy (since it's a bit of a tossup as to whether all LQ1's can even HIT 6K in 3rd gear).

 

On the other hand, going off of the dyno charts of seen for stock to lightly modded LQ1 auto's, the IDEAL (power/performance-wise) shiftpoints appear to be 7000rpm for 1-2, 6700rpm for 2-3 and 6500rpm for 3-4.

 

Maybe YOU can pick a happy medium between longevity and performance (and also remember, you can hold 2nd and 3rd gears manually [which is why *I* would probably get the lower set of shifts]..............maybe you should talk to FFP and see if they can play with the shift logic to hold 1st manually too :wink: ).

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Damn those engines just keep pulling past 80km/h like nothing! :shock:

 

Whenever I see/hear those high RPM engines really go it makes me want one!

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Ok............I got the video to download finally (I think maybe others were trying too....).

 

It looks to me as though your car does 1-2 at 6300rpm/44mph and 2-3 at 6150rpm/82mph.

 

Now, I also noticed that your torque convertor remains unlocked in 2nd gear for a LONG time after the shift (the revs don't fully equalise to the normal 60-E 3-5% slip until around 75mph)..........this is why you only drop to ~4200rpm off of the shift (a manual tranny with those gear ratios would go from 6300 down to ~3400rpm [2.921 1st gear, 1.568 2nd gear]...........so YOU have ~800rpm worth of slip right off the shift). The same thing occurs off of the 2-3 shift, although it doesn't last quite as long.....things are locked back up by ~95-97mph. Here, you drop to ~4400rpm off of the 6150rpm shift, which is about 500rpm worth of slip.

 

This is important stuff to know, since auto tranny's obviously slur out the shift, and delays in torque convertor lockup artificially raise rpm OFF of the shift.

 

Now, lokking at this dyno chart of a stock LQ1 auto:

 

hypertech.jpg

 

You can see that at your 6300rpm 1-2 shift you (at least THIS example of an LQ1 auto) are making ~157-158whp (at 6300)..........but AFTER the shift, you drop down to 4200rpm where you only have ~133whp available for acceleration. Same on the 2-3 shift........at 6150rpm in 2nd, you have ~163whp available, but at 4400rpm (in 3rd gear after the shift), you are sitting at ~140whp.

 

So..........we KNOW that it is beneficial to shift higher..........but how much?

 

Extrapolating from your video, it seems as though any WOT 1-2 shift should leave you with ~67% of the rpm you had at before the shift (4200/6300). So, a 7000rpm shift would drop you to 4650-4700rpm in 2nd gear...............and looking at the chart........wait.......oops..no 7K (rev limiter cuts at 6650-6700). But........extrapolate along the curve, and I think we can agree that the LQ1 makes *roughly* 148whp at 7K rpm.........and at 4650-4700rpm.......~148whp....... :D ..........THAT is an ideal shift (NO power loss off of the shift).

 

Doing the same thing for the 2-3 shift, you can see that the car goes from 6150rpm down to 4400rpm..........~72%. Going back to our chart and checking out 6700rpm (~153whp) and multiplying by 72% you get ~4800rpm..........where you have ~153whp. Another good shift :D

 

Now for the 3-4 shift, it's hard to tell exactly how things will work out (since we don't have video that goes that high), but since there is less and less slip between each shift (~800rpm worth off the 1-2 and ~500rpm for the 2-3), I figure that an IDEAL shift would be around 6500rpm.......dropping you to 5kish in 4th (assuming 350-400rpm worth of slip). The thing is, since your car is sitting at 4850-4900rpm at 100mph, that means 6500 in 3rd is about 135mph..........and I rather doubt that your car can even GET that high (it'd be close......). Not to mention how long your car would be stuck at HIGH rpm in 3rd gear (making the oil [and probably tranny] temp SKYROCKET).

 

 

 

So..............for IDEAL performance oriented shifts, you should look at:

 

1-2 7000rpm

2-3 6700rpm

3-4 ~6500rpm

 

But as I stated earlier...........*GM* says (as per the GMpowertrain webpage) the tranny is "rated" for:

 

1-2 6500rpm

2-3 6250rpm

3-4 6000rpm

 

So.............it's your choice what rpm to pick.

 

THEN.....when you have the rpm picked out, we can go back to your video and take a look at what SPEED you need to set them at :D

 

Make sense?

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Dammit now I need a video that goes over 100. lol give me a couple of weeks.

 

DAMN IT, why did I sell that to you.......Thats sounds so cool.......I don't think I'll ever forget that sound.

:D

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I'm giong to try and get another vid, this time manually shifting 2nd and 3rd with a longer stretch of road since I almost ran out, hence why i stopped at 100mph. Plus bad struts make the rear very uneasy in the pants :-).

 

Bigbuls, you are the most knowledgable person I have encountered in awhile...well, I work retail, so I get too many asshats.

 

I have another version from a 30mph roll, the RPMS skyrocket to 5 then climb to 6 then the shift drops and continues.

 

I hve noticed how the MPH varies with shifts. FOr example, flooring it from 10-30mph, the RPMS skyrocket and I get some wheelspin...

 

At 40-50mph, flooring it does not cause the same knecksnapping power, but rather a gradual climb from whatever RPM it sits at.

 

Then 60-70pmh, I get the RPM skyrocket again.

 

By the way, Vegeta, is there any way to hold 1st? I'm sending the chip out as soon as we can figure out the ideal MPH.

 

If you need some vid to see how the car responds at different RPM's, mph, let me know, I need the chip before the 16th.!

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