PDA

View Full Version : Loose converter/shifting.



VHR
October 10th, 2007, 07:16 AM
I'm battling a 01 F body that I cant make shift before it hits the limiter @6500. Because the converter is so loose,(flashes to 5000 approx) I dont think I could move the shift @rpm down without confusing the pcm.
My next thought is to shift by mph. I'm wondering how best to go about that. Would you put the shift @rpm to say 3000 then play with the shift @ mph to get the shifts I wanted? What would you recommend with regard to part throttle shift tables? Any help would be greatly appreciated.


Thanks, Vinny.

WiseGuyZ06
October 10th, 2007, 10:42 AM
I'm battling a 01 F body that I cant make shift before it hits the limiter @6500. Because the converter is so loose,(flashes to 5000 approx) I dont think I could move the shift @rpm down without confusing the pcm.
My next thought is to shift by mph. I'm wondering how best to go about that. Would you put the shift @rpm to say 3000 then play with the shift @ mph to get the shifts I wanted? What would you recommend with regard to part throttle shift tables? Any help would be greatly appreciated.


Thanks, Vinny.

I think I have a solution for you.... lemme check

WiseGuyZ06
October 10th, 2007, 11:05 AM
Ok here is how you make the tranny shift based on MPH and NOT on RPM...

1. Go to transmission calabration in the tuning tool

2. Click on general

3. Click on parameters

4. Change (D1206) upper threshold to 100

5. Change (D1207) lower threshhold to 99.9

This method disables the WOT shift tables in the pcm and it allows you to use the part throttle tables insted, which are in MPH

OK HALF WAY THERE...

Next go to TRANSMISSION CALABRATION in the tuning tool again

1. Click on 1->2 shift speed look at 100.0 cell on the left and change it to whatever MPH you want the trans to shift at...

then do the same to 2->3 and 3->4 shift speed tables and change the 100.0 cell to whatever MPH you want...

YOURE DONE....

Its a PITA to cross MPH with RPM to try to findout what MPH you want the trans to shift at... It can be done it just takes time.....

VHR
October 10th, 2007, 12:00 PM
"Its a PITA to cross MPH with RPM to try to findout what MPH you want the trans to shift at... It can be done it just takes time....."


I kind of anticipated that part of tuning it this way because there is a lag of about 1k rpm at 1-2 and about 600 at 2-3 so I think I'm going to have to guess at those mph targets. I think it's my way forward though.

I greatly appreciate your taking the time to help.

Vinny

WiseGuyZ06
October 10th, 2007, 12:43 PM
"Its a PITA to cross MPH with RPM to try to findout what MPH you want the trans to shift at... It can be done it just takes time....."


I kind of anticipated that part of tuning it this way because there is a lag of about 1k rpm at 1-2 and about 600 at 2-3 so I think I'm going to have to guess at those mph targets. I think it's my way forward though.

I greatly appreciate your taking the time to help.

Vinny

I hear ya bro.... BUT Ive done it so its not too bad...At least you dont have to mess with MPH and RPM...

I have a 4500 vig stall and it dont flash at 5000rpm, 3900 RPM max with my old 346ci setup footbreaking at 2500 RPM's at the track.. what brand stall do you have and whats the setup of the motor??

I still use the WOT shift tables, BUT I can use part throttle whenever I want...

VHR
October 10th, 2007, 01:31 PM
The car I'm having trouble with is not mine so the specs as best I know: ls1, MTI in Texas did the car so it has ported stage II heads, cam is around 585" lift,
3.73's. The converter is a Yank 4400 that he sent out to be tightened but still flashes about 4200.

I honestly don't know why it hits the limiter in 2nd, but it has not responded to lower the shift at rpm, even with lowering the shift at mph. It is definitely not mechanical in the trans because you can see that its not commanding the shifts in the data logs.

He's this close to making it a manual valve body, but I still would like to see if shifting by mph only will help.

As an aside, MY car usually does not hit limiter-but I shift at 6800 and the limiter is set at 7800. He does not want to go there.

Thanks, Vinny

WiseGuyZ06
October 10th, 2007, 01:55 PM
The car I'm having trouble with is not mine so the specs as best I know: ls1, MTI in Texas did the car so it has ported stage II heads, cam is around 585" lift,
3.73's. The converter is a Yank 4400 that he sent out to be tightened but still flashes about 4200.

I honestly don't know why it hits the limiter in 2nd, but it has not responded to lower the shift at rpm, even with lowering the shift at mph. It is definitely not mechanical in the trans because you can see that its not commanding the shifts in the data logs.

He's this close to making it a manual valve body, but I still would like to see if shifting by mph only will help.

As an aside, MY car usually does not hit limiter-but I shift at 6800 and the limiter is set at 7800. He does not want to go there.

Thanks, Vinny

Whats your car??? details... 7800 rpm's??? details please...

A 4l60e manual valvebody would be cool.. its the trans-go kit... I dont know anybody who's tried it yet

VHR
October 10th, 2007, 03:22 PM
Mine is a 00 ls1, stock bottom end except for ls2 timing chain guide and ported oil pump. Oh, and the pistons I had to notch for valve clearance-I used an Isky tool that centers in the valve guides. I did have the pan off to clean the debris out from drilling the block for the chain guide, but not one rod bolt was loosened. Motor only has 40k on it.

The heads are home ported 5.3 with 2.00" Manley valves. I will tell you up front, the heads didn't turn out that well-flow too well at low lifts, too turbulent at high lifts. I learned first hand how peculier these heads are. Flat milled .050. Will not do that ever again, will angle mill. Try better next time.

This brings us to the root of all evil in this combo, the cam. Now remember, this whole deal was just an experiment. The cam was custom ground by Bullet cams.

.630/.640, 302/308 on a 109 ctr. The lifters are stock GM but blocked, limited travel approx .015. To use stock rockers I had to have pushrods made(Smith Brothers) and I ended up with about 8 different lengths over about an .025 range. I still had to do some shimming to the rocker pedestals. If you want to know how to make rocker shims from feeler gauge stock, let me know. I'm a believer in stiff pushrods so they are 3/8. Tight, but no clearance issues with stock rockers.

I really didn't intend to spin the motor this high but...my converter vendor missed my stall speed by, oh, about 3000 rpm. Flashed to about 2200. 1.7 60's. It was late in the year, two or three weeks left before the track closed, and I guess I did want to see where the motor would pull to and gears were cheaper than a day on the dyno. Out came the 4.10's in went some 4.88's. 60's came down to low 1.6's ant my best et came down to 11.36. Six hundredths slower than my buddies car.

This year, late again after learning to weld and putting a roll bar and a new converter in...I'm only 2 thousands away. But I'm not done yet. I have an LS6 intake cut open to shorten the runners and if I can get it to stop breaking the cut out section, I'm hopeful.

I hope I haven't bored you with too many "details". I may nut's but stand or fall, I have the satisfaction of knowing I did every GD thing myself except the trans.

I just counted my slips, 40 passes so far.

Vinny

WiseGuyZ06
October 10th, 2007, 04:25 PM
Mine is a 00 ls1, stock bottom end except for ls2 timing chain guide and ported oil pump. Oh, and the pistons I had to notch for valve clearance-I used an Isky tool that centers in the valve guides. I did have the pan off to clean the debris out from drilling the block for the chain guide, but not one rod bolt was loosened. Motor only has 40k on it.

The heads are home ported 5.3 with 2.00" Manley valves. I will tell you up front, the heads didn't turn out that well-flow too well at low lifts, too turbulent at high lifts. I learned first hand how peculier these heads are. Flat milled .050. Will not do that ever again, will angle mill. Try better next time.

This brings us to the root of all evil in this combo, the cam. Now remember, this whole deal was just an experiment. The cam was custom ground by Bullet cams.

.630/.640, 302/308 on a 109 ctr. The lifters are stock GM but blocked, limited travel approx .015. To use stock rockers I had to have pushrods made(Smith Brothers) and I ended up with about 8 different lengths over about an .025 range. I still had to do some shimming to the rocker pedestals. If you want to know how to make rocker shims from feeler gauge stock, let me know. I'm a believer in stiff pushrods so they are 3/8. Tight, but no clearance issues with stock rockers.

I really didn't intend to spin the motor this high but...my converter vendor missed my stall speed by, oh, about 3000 rpm. Flashed to about 2200. 1.7 60's. It was late in the year, two or three weeks left before the track closed, and I guess I did want to see where the motor would pull to and gears were cheaper than a day on the dyno. Out came the 4.10's in went some 4.88's. 60's came down to low 1.6's ant my best et came down to 11.36. Six hundredths slower than my buddies car.

This year, late again after learning to weld and putting a roll bar and a new converter in...I'm only 2 thousands away. But I'm not done yet. I have an LS6 intake cut open to shorten the runners and if I can get it to stop breaking the cut out section, I'm hopeful.

I hope I haven't bored you with too many "details". I may nut's but stand or fall, I have the satisfaction of knowing I did every GD thing myself except the trans.

I just counted my slips, 40 passes so far.

Vinny

Cool, good luck....

VHR
November 4th, 2007, 03:23 AM
Just a word of thanks Wise, that worked.

Vinny

WHYTRYZ06
November 4th, 2007, 06:48 PM
Just a word of thanks Wise, that worked.

Vinny

What worked vinny??? Did you do what I told you to do with the part throttle table??? and was it successful????

VHR
November 4th, 2007, 11:33 PM
Yes I did. Modified the upper and lower thresholds, lowered the shift at rpm to 4000 and used the part throttle tables. I tried it on my car first because oddly enough mine started to nip the limiter as well. It did take few passes to sneak up on the shift points, but using my data I was able to hit my buddies shift points right away. Not wanting to take any chances, I did set all the shift speeds from 50% up to my target MPH.

Thanks again for taking the time to help. Vinny

WHYTRYZ06
November 5th, 2007, 03:11 AM
Yes I did. Modified the upper and lower thresholds, lowered the shift at rpm to 4000 and used the part throttle tables. I tried it on my car first because oddly enough mine started to nip the limiter as well. It did take few passes to sneak up on the shift points, but using my data I was able to hit my buddies shift points right away. Not wanting to take any chances, I did set all the shift speeds from 50% up to my target MPH.

Thanks again for taking the time to help. Vinny

No problem vinny.... So It shifts alot better now? Maby I should do that way too.. I never messed with it that way too much, but ill start as soon as the new motor is in. Glad I could help...

P.S.

What did you modify the upper and lower thresholds to?? and depending on what you did with that why did you lower the shift @ rpm to 4000?? If you changed the thresholds to what I posted, It would disable the WOT shift @ rpm table....

So Im kinda at a lost to some of the changes you made... Could you please specify (sp?) what changes you made to each table??? Thanks

VHR
November 5th, 2007, 05:03 AM
Let me set the scene: you're at a track rental and and your car hits the limiter on the first pass and rain is on the way, so who knows how many passes you'll get. Alright you p.o.s. PCM-you are going to shift.

I set the shift at rpm tables way down to 4000 so there is no chance that this dummy PCM will think too much. I put WOT upper threshold d1206 to 100 and the d1207 lower threshold to 99.9. Next I put d0901 and d0902 to the speeds I wanted to hit in the 100% box,then I thought-"Better not give this stupid thing any reason to get confused". I changed all the speeds from 50% up to 100% to those speeds. I went to the downshift at vss and set those speeds 20 mph less than the up shift speeds.

I aimed low and it shifted close to where it should have so from there it was just a matter of going up in 2 MPH increments to get where I wanted. I don't know if I had to change all those speeds but I couldn't take the chance under those circumstances

WHYTRYZ06
November 5th, 2007, 08:19 AM
No shit, cool ill give youre method a try. Now you helped me out..... What track? lebanon valley?

VHR
November 5th, 2007, 09:29 AM
Keep in mind there is a pretty good lag in the shifts mechanically, about 1500 rpm in the 1-2 and about a 1000rpm in the 2-3 in my car. One of the really cool features of EFILive is that when you click on one of those shift at vss boxes, it shows you at the bottom of the screen what rpm that would be in each gear.

Yes the track was Lebanon Valley.

WHYTRYZ06
November 5th, 2007, 09:35 AM
Keep in mind there is a pretty good lag in the shifts mechanically, about 1500 rpm in the 1-2 and about a 1000rpm in the 2-3 in my car. One of the really cool features of EFILive is that when you click on one of those shift at vss boxes, it shows you at the bottom of the screen what rpm that would be in each gear.

Yes the track was Lebanon Valley.

Yep I know that trick... did you use that trick as a starting point for adjusting MPH?? So Im guessing on the 1-2 shift you set the MPH 1000rpm higher than youre desired MPH on the shift at vss?? Since you have the mechanical issue w/the trans. I hope I word'd it correct??? get what im sayin???... 4l60e's blow......I know I have one...

VHR
November 5th, 2007, 09:45 AM
Yes sir, thats exactly how. Damn handy if you ask me.

WHYTRYZ06
November 5th, 2007, 09:46 AM
Yes sir, thats exactly how. Damn handy if you ask me.


Im gonna pm you my #....