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Back from the track with video
https://slantsix.org/forum/viewtopic.php?t=26820		 Page 1 of 2
Author:  Bren67Cuda904 [ Thu Jan 24, 2008 7:32 am ]
Post subject:  Back from the track with video
The results are in...sort of
Lets set the stage (pun intended)
5 or 6 weeks ago I ran 15.695 @ 84.86MPH. If I am remember right the temp was about 55*-60* low humidity. 3.07 rear gear, 904 with low gearset, 3200 stall midwest converter that I can foot brake to 3100, No Gear vendors installed or exhaust cut out.
R/T .245
60 2.160
330 6.406
1/8 9.946
mph 69.46
1000 13.044
1/4 15.695
mph 84.86

Yesterday the temp was around 70* and higher humidity. First time down ran a 15.857 @85.05 Notice that the mph is faster but the time is slower. (not sure how to interprete this) This run was with the Gear Vendors installed and split shifting 1-2 , 2-3. Exhaust was NOT opened at this time. Can the temp difference be the difference between the to times?
r/t .152
60 2.214
330 6.524
1/8 10.107
mph 68.40
1000 13.210
1/4 15.857
mph 85.05

The next couple of runs was about the same as above while I was learning how to time the split shifting. I am a slow learner.

Then I open the exhaust. :shock:
If you are used to shifting based on how the engine sounds, then shifting with an open exhaust is a new learning experience. :oops: First time down with open exhaust, split shifting all gears, hitting the rev limiter twice, it ran 15.492 @ 86.27
r/t -.105
60 2.153
330 6.334
1/8 9.827
mph 70.24
1000 12.882
1/4 15.492
mph 86.27

Second time down with open exhaust split shifting and only hitting the rev limiter once on the far end of the track.
r/t .038
60 2.158
330 6.290
1/8 9.766
mph 70.08
1000 12.780
1/4 15.330
mph 88.26

I have video of the last to runs. I one of them you can hear me hit the rev limiter. This video I hit it twice but you can't hear the second time, as I am to far down the track. The second video I hit it on the far end of the track and you can't hear that one either.

http://www.youtube.com/watch?v=aRIukwAw-xk 15.492
http://www.youtube.com/watch?v=_zpi2DGov4A 15.330
Author:  sandy in BC [ Thu Jan 24, 2008 7:57 am ]
Post subject: 
Nice presentation!

The better time with cutout may indicate your exhaust system is holding you back.....or that you drive it harder with loud exhaust...or that cool HP is faster (open exhaust is cool).

The weather always plays a part.

What is your split shift procedure? Do you manually shift the trans?
Author:  66aCUDA [ Thu Jan 24, 2008 8:36 am ]
Post subject: 
Hey Bren nice vidieos thanks for sharing.
Frank
Author:  Joshie225 [ Thu Jan 24, 2008 8:45 am ]
Post subject: 
A 3 MPH gain just by opening the exhaust is pretty big. This says more to me about how poor the downstream exhaust system is than anything.

I once put a generic 2 1/4" Walker parts store muffler on my Dart to replace the failing generic turbo muffler that I was afraid was disturbing my neighbors. Car was quieter, but slower.
Author:  argentina-slantsixer [ Thu Jan 24, 2008 12:12 pm ]
Post subject: 
not to hammer on you, but this time flips tells me that your motor's up for large tube headers split exhaust balanced, gong to 2.5" twin tailpipes from before the crossmember to the tail. You can add a cut there, but you will gain more than 5 tenths if you get a good flowing exhaust installed. You should run big primaries, like 1.75" for about 35 inches, then a relatively short collector that will blend 123 and 456 separatedly into 2 2.5" pipes. You can balance them (or not, if you like jag's sound... hehehe and have torque to spare) at about where the tailhousing on your 904 begins... (there's a procedure that SSD has described using a heat sensitive copper paint)

Congrats on those numbers! impressive!

now, how bout a pass w/o A/C on? :lol: :twisted:
Author:  Bren67Cuda904 [ Thu Jan 24, 2008 3:37 pm ]
Post subject: 
These are my conclusions.
The GV by its self will add .1-.0 The real benifit is you can run a lower rear gear and still enjoy the highway. I plan to reinstall the 3.55 gear. This will give me a 2.77 final drive which should be good for the highway.
My current exhaust system is inadiquit. I'll be looking for headers soon. :shock: :lol: :? yes you are all these. :) The Hemi is sold. It just doesn't make any sence to backup and spend money again. If its going to be a V8 it should be another car. I may change my mind, but its really the best choice, considering I am this far into it.

gotta run
Author:  Doc [ Thu Jan 24, 2008 4:19 pm ]
Post subject: 
At what RPM were you shifting? Where is the rev limiter set?
(did I miss that?)
It may go faster if reved a little higher.
DD
Author:  Bren67Cuda904 [ Thu Jan 24, 2008 5:14 pm ]
Post subject: 
I am "attemting" to shift at 5100. Anything higher has shown a drop off of power on a chassis dyno. The limiter is chiped at 5800. If the trans would shift from 1st to 2nd when selected and not wait 2.5 -3 seconds that would help alot.
The GV takes about 1 sec to shift up and about .001 to shift down. :)
What I would like the trans shift points to be raised so I could just put in in Drive and then work the overdrive button. Not sure how bad this would make part-throttle shifting on the street though.

Someone asked about split shifting procedger.
1st to 5000rpm- push OD button for a 5100rpm shift, move shifter to 2nd @ 4600 and hope for a 5100rpm shift. As soon as you feel it shift push button to drop OD, at 5000 rpm push button again for a 5100rpm OD shift. Drive though traps some time later and put shift in drive. RPM though traps?? didn't look :oops:
Author:  Dart270 [ Thu Jan 24, 2008 7:42 pm ]
Post subject: 
Surprising. Given how restrictive your Y-pipe looked, headers and a good Y should get you another 3 tenths.

Lou
Author:  slantasaurus [ Thu Jan 24, 2008 8:30 pm ]
Post subject: 
Were any of your dyno runs with an open exhaust ? If not, then you might find that there is more power above 5100 RPM with freeed up exhaust system.
Author:  Bren67Cuda904 [ Fri Jan 25, 2008 9:30 am ]
Post subject: 
Quote:
Were any of your dyno runs with an open exhaust ? If not, then you might find that there is more power above 5100 RPM with freeed up exhaust system.
no
Author:  440_Magnum [ Fri Jan 25, 2008 10:52 am ]
Post subject: 
Y'know, despite all the pain and dead-ends you've gone down....


That car looks and sounds GREAT. Bloody great. And those timeslips are far from sucking, too. :-)

You may not be pulling the rear-wheel horsepower of "a stock 440," but you are probably as fast, if not faster, than my 440 car. I'm going to have to take it to a track one of these years....
Author:  Slant Cecil [ Fri Jan 25, 2008 6:13 pm ]
Post subject: 
Splitting all those gears may work if you had a narrow power band. Each shift takes time and that's time when the car is not under power, especially early in the run when most ET is made.
If you look at the predictions on your other thread, mine was the most negative, from zero change to a .10 gain in ET and you gained ET.
I've always thought your biggest problem for full potential was lack of headers. Put some on, see what it does and you will probably then be looking for a Clifford intake to try.
Author:  Bren67Cuda904 [ Fri Jan 25, 2008 6:25 pm ]
Post subject: 
I'll agree that the 904 shifting takes time for the shift to be made but the GV does not. Power is always being transfered. The planetary ring is "grabbed" and stopped in mid flight and held, forcing planetary gears to over drive. Knowing all of this it still seems to "use up" more than the 1hp per 400hp as advertized.
Author:  runvs_826 [ Sat Jan 26, 2008 5:15 pm ]
Post subject: 
That is a very good looking car, and what were you running against? It looked like a WRX or some kinda tuner. If I can keep up or beat a WRX with my slant (even though a straight line isn't their strength) I would be stooked. The exhaust should free up some good power, but the shifting is what intriques me. Can you put in your 3.55 and just do a standard 904 shifting? That way you can just save the gear vendor for highway use. My uncle's Cummins we raced at woodburn, I shifted 2-3-4-5 at 3800rpm. At MATS I think I'm going to try a 2-4-5 shift cause the torque and boost will push the truck faster than the time it takes me to shift. I understand sticking with the slant while your this far in. I'm more than sure if you read up and try some stuff yourself you can have a respectable car. I know despite what people argue the "hemi" stock Chargers were running 15's, the very impressive SRT-8 6.1 were running 14's which I full heartly believe you can dip into with some more work. Good luck this upcoming season, must be nice to be able to race, all we got is ice.
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