Th 400 and timing question?

[jasjamz]

I have a manual valve body TH 400 with a 3500 stall. I am thinking of going back to the stock ecm and a chip in the spring.(bye bye gen 6 dfi) My question is that I see alot of chip out there with timing being changed in high gear. Does the ecm see the same mph displayed on my digital dash?(which is also 10-15 to fast as is) Does it read MPH to change the timing?

 

[J Banning]

From what I understand, the ECM gets MPH from where the speedo cable goes into the back of the dash cluster.

Also, for some chips you'll need to have your shofter linkage hooked up to the steering column so that the ECM knows what gear you have selected in order to change the timing at the shift points.

Best bet is to get in touch with your chip maker to find out what is needed for sure.

Hope that helps.
-Banning.

 

[jasjamz]

Thanks! I will get in touch with Eric since I will be going to alky. Still gotta get a modded ecm and translator/with a big maf. I still use the stock shifter with the reverse pattern shifter plate from member Yullose.

 

[yullose]

Eric burns my chips with no VSS/NSS signal input. The speedo doesn't work and the neutral safety switch isn't hooked up.

It's still fully adjustable, but you can't make the timing/fuel adjustments different between 1/2 and 3/4 gears like you would with a 200R4. Whatever adjustments you make in the chip, will be the same in all three gears.

He was dead-on with the chip-tune on my combo... I went in the 10's using his chip "right out of the box" with no adjustments.

I wouldn't change a thing.

 

[PhilM]

With the 400 I use no VSS input - just to drive the autometer speedo. With the 200, you could alter timing when the TCC was locked - not to mention that the ECM was used to enable the TCC lockup - you can do this with the DFI if you wanted but since your 400 has no TCC, then there isn't a need IMO to adjust timing other than what the base advance table already provides you with.

Why are you going from the DFI to the stock ECM anyways? It's a better system than playing with chips and translators once you've spent the time learning how to tune.

Phil

 

[jasjamz]

Im all confused.

The tuning part will require more time than i have to spare so I'm really not up for it now. I want to start it without it stalling, no jumps and skips on light or moderate acceleration,(stumbles) and other issues that arise. I have never been able to successfully get into the program and my GN guy is big on b2b fast systems and big stuff ecm's. Seems that its easier to go back to basics and start the learning that way. But now with stuff like the power logger, wide band o2, modded ecm, translator, ls1 maf, i would be clost to the price of a used fast. I want to add alky in the spring also. Just seems easier to change chips as needed.

 

[PhilM]

Idk, I would still stick with an aftermarket "tunable" EMS over swap and rock deals... Like anything good... bigger learning curves yield the best rewards.

Can't u find someone to help you in the area - or at least give you a nice base and possibly a few pointers? What do you mean you can't "get into" the program? Are you locked out or just don't understand what's goin on?

Accel DFI, Fast, BigStuff, Motec, AEM, Autronic, MegaSquirt, Stock ECM - all of them are the same in principle... They aren't changing the basics of how an engine runs! A decent tuner doesn't care what EMS he is using. It may take a couple reads of the manual and some quick flying around the GUI, but other than that it doesn't matter.

Phil

 

[jasjamz]

I kinda want to keep it because of the cost. Its the cheapest option. I could get a wideband setup and be out of $300 vs. the other two options. I had found an old serial port style laptop and when it would ask edit ecu or the other option it would never let me change things. So I figured instead of being the pest to my Gn man with constant calls and drop in's trying to learn this Gen 6 I'd do us both a favor and upgrade to a fast b2b. Then, after seeing these guys run in the tens with stock ecm's,(Grumpy, Kevin Hess, and many others) I figured that would be the best.(chips) Then I could still run race fuel or pump gas before I get the akly kit. Now thats $300 in chips! $200 for ecm modded, Etc...

I see you point though and it is a good one! I will try to find a manual, a dfi disk to reload it, and a Innovative setup for a wideband. My Gn man is always swammped with work and the only other guy around here that really deals with Gn's that I know of is Tom with the CTS(LC2 powered). ANS performance is long gone so its slim pickens. And you know how us GN owners are picky about who tampers with our babies. I really appreciate your help on this and the others who post. Keep the info and opinions coming guys.

 

[Eric Stage I]

Does the ecm see the same mph displayed on my digital dash?(which is also 10-15 to fast as is) Does it read MPH to change the timing?

For a TT chip, it's good to have a somewhat accurate MPH reading to get the full benefit of variable spark timing. It does look at MPH and varies timing accordingly.

Regards,
Eric

 

[jasjamz]

eric stage II

I can get the MPH corrected if need be which makes me wonder if thats causing the DFI problems also?? (!!oops stage I)

 

[Eric Stage I]

I don't think the Gen 6 pays any attention to MPH that I'm aware of.

Eric

 

[PhilM]

Nope - no mph needed