MY tranny is being built as we speak and the builder recommends going vacuum modulated so that the computer isn't pulling line pressure during the shifts. What do you guys think? I plan on doing it just because I trust his judgment, but I'd like to get a little more info on it.

 

i think your builder is ignorant of the advantages of a computer controlled transmission, and should stick to building 700R4s or whatever it is hes used to building.

 

I disagree... I love my vac modulated 4L65E

 

my brother has it done on his car, and it has worked great, the only thing is that your check engine light will be on due to the computer not controlling the line pressure, but you can delete it with any tuner program. his shifts are very firm and it seems to respond better under full acceleration. hope this helps some.

 

the thing I like it is its progressively firm according to engine vac... easing around town, it shifts light and easy... get in the throttle, and it will put you in the seat

 

Thanks to you and silver-mod-o. It's already done (one day turnaround, that's insane) and I pick it up in the morning so I'll know soon enough how much I like it. He said there's a sensor that comes with the kit that goes in the pan that will keep the SES light from coming on.

It's still almost entirely computer controlled, the only thing that isn't is the line pressure. He's built tons of race trannies and I'm not questioning his competence, just exactly what this does for me. Thanks for not answering my question.

 

mine has been vacuum modulated for over a yr. now thats the way to go imho works great

 

The way FLT sets up their Vacuum Modulator it does not throw any lights or codes.

 

nice to know when i do mine, thanks.

 

My FLT 4L80E is vacuum modulated,shifts soft at part throttle and hard enough to jar your fillings loose at full throttle.It's great.

 

I have a few vacuum modulated 4L60E's in the nines, running very successfully. I have been using the vacuum modulator on 4L60E's for over 10 years very successfully. There has only been one case that the vacuum modulator did not work out very well for me.

 

Are we talking about the GTO? If so I would give it another shot using the method in which we discussed on the phone. Chuck(the owner of FLT) was probably one of the first to use this with the hd-2 kit. When he told the guy's over at Trans Go what he was doing they could not believe it. Pro Stock John was one his first in a group of units that Chuck had tried this in with huge success. I remember when I first saw this set up about 8 years ago I was a little sceptical. But as Chuck told me as a builder you have to be willing to try new things. I did redesign the kit a bit however, I have never been one to follow directs well. LOL We do build these units both ways however I really like what I see on the Dyno with the modulator set up. As stated above by members with my units, they love it. Good luck to you and let us know if there is anything we can do for you in the future. Vince

 

my 4l60e is vacuum modulated shifts great love it

 

Got it back, I think I like it. Havn't really gotten to beat on it yet though. Street tires make WOT a waste of time. Thanks for the input fellas

 

I'd say that you have no clue what you are talking about... Maybe if you made enough HP to kill a stock tranny, you'd know that the vacuum mod is the 4L60e's best freind. Infact I don't consider it a built tranny with out one.