9C1'Stangkiller

iTrader: (1)

Alright, since the Impala SS forum is down I've come here for advice. As you can see in the title, I'm starting tuning with Tunercat. Also I should note I have a mail order tune from Bryan Herter I'd like to tweak just a bit. I've fixed a couple things so far, like the speedometer with the 3.73's and 295/50R15 tires, and scaled back the shift MPH tables to match. One question I have, is what's a good shift RPM for a stockish B-Body LT1? Stockish like 52MM TB and a K&N FIPK 2, and 2 1/2" catback exhaust. Right now it shifts around 5500 and it doesn't seem to run out of power, but I'm wondering if shifting it sooner or later would be better. Second, I'm happy with the shift firmness, as Herter increased line pressure for the TB and I've also added a Transgo shift kit, but I'm wondering about the shift times. IIRC, it seems to me I've heard about guys taking thiers down to around .400 sec. Here are mine.

Low alt.
0.600 0.500 0.000
0.600 0.500 0.000
0.600 0.550 0.000
0.650 0.600 0.000
0.700 0.650 0.000
0.750 0.725 0.000
0.750 0.800 0.000
0.800 0.825 0.000
0.800 0.825 0.000
0.800 0.825 0.000
0.800 0.825 0.000
0.800 0.825 0.000
0.800 0.825 0.000
0.825 0.825 0.000
0.825 0.850 0.000
0.825 0.850 0.000
0.825 0.850 0.000

High Alt

0.650 0.500 0.900
0.650 0.500 0.900
0.650 0.550 0.900
0.700 0.600 0.900
0.750 0.650 1.000
0.800 0.725 1.000
0.800 0.800 1.000
0.850 0.825 1.000
0.850 0.825 1.100
0.850 0.825 1.100
0.850 0.825 1.100
0.850 0.825 1.100
0.850 0.825 1.100
0.850 0.825 1.100
0.875 0.850 1.100
0.875 0.850 1.100
0.875 0.850 1.100

I'm looking to take any time off my 1/8 mile that I can, so do you think there is any room for improvement? I'm one of the lucky ones with a track almost in my back yard so any changes will be tested right away. Other than that, I'm very happy with the tune, I'd just like to a little faster, even if it's only a few hundreths. TIA.

buffman

iTrader: (9)

I can look at my shift times, but I dont think they've changed. I wouldnt **** with them IMO.

Josh does the car complete the shift at 5500rpm or does it command the shift at 5500rpm? If it's completing the shift at 5500rpm I think that's completely fine for a B-car as long as you dont feel the power dropping off. If it's commanding the shift at 5500rpm, IMO i think that's too high for stock springs

9C1'Stangkiller

iTrader: (1)

Matt, just the person I was hoping to see. It completes the shift at 5500. I have the shift light on the tach set to 5500 and it just flashes real quick.

buffman

iTrader: (9)

I'll have to look at the shift times when i get home. Im at school right now passing the time while In Access VBA class :garbage:


As I stated as long as the car isnt loosing any power by shifting that high then you should be set. Your car prolly doesnt have near the miles mine does (?) but with 135k on my stock springs, I was getting the infamous valve float at around 4800rpm. I had shifts completed aroudn 52-5300rpm, until i got new valve springs

9C1'Stangkiller

iTrader: (1)

Sounds like fun times. My car only has about 108K, but I know the stock valve springs suck teh dick. I have some new springs with 1.6 RR's in the closet waiting for a day I'm feeling froggy. And since this is my thread, I'll go off topic. What the hell is up with the ISSF???

buffman

iTrader: (9)

well we were supposed to upgrade to Ubb threads, however it was to an untested version or some BS like that. So that got cancelled. I recall being told that the forum got moved to a new sever. Then it seemed the server was having issues with the forum, then it went down. Who knows if they're doing the update now. ISSF is a great community but until hack realizes the need to step up to a real forum software, it's not going anywhere. Bobistheoilguy.com went to UBBthreads and it's horrible IMO. a search results doesnt just return threads as results. It returns every post in that thread as a search result, and the results are limited to 200!!!

gillbot

iTrader: (27)

http://www.monodax.com/forums/

9C1'Stangkiller

iTrader: (1)

Thanks man!

infinitebird

iTrader: (11)

I put mine down to .200 and had no issues.

I've heard from others that you don't want to have them below .150 b/c the trans does not like that.

I would get rid of the zero column in the first table and put in something higher.

buffman

iTrader: (9)

I checked my shift times on my tune and they are what yours are. my tune is a modded BH tune.

tbsimmons

As Matt said if you have stock springs watch going much higher.
When mine had an auto, I valve springs and mine was starting the shift at 5500.
So I would not go to much above that.
Watch the tranny also.
If it starts to slip a little, that will raise the number the car completes the shift.