KRMaxima21

I was thinking about this last night when I was looking at the JWT ECU. Everyone says the automatic tranny is the achilles for anyone looking to go fast with mods on an auto. Even though this would cost alot of money (major saving), what do you think would be the benefits to take the JWT upgraded tranny computer with the switch module and adding a Stage 2 VB kit? I'm thinking about experimenting with the idea this summer but just wondering has anyone on here ever done it? I've had the Stage 2 VB on my old 3rd gen and fell in love with it the moment it chirped into second. I'm just thinking that if you change the shift points (I'm guessing the point in the RPM's where the tranny shifts. ex.-the power and comfort switch in the 3rd Gen) which the computer does and then add a VB mod to give you full line pressure through the shift (no shift lag) wouldn't it help you get to your top end power quicker therefore lowering your 1/4 ET? Okay, let the bashing begin......

Chickan

iTrader: (12)

it would allow for quicker shifts yes, but most of the drive train loss due to an automatic is due to the tranmission itself, not how fast you shift. You would gain some top end HP simply because of the rev limiter being raised. You might get to your top end "quicker" as you say, but nothing dramatic.

Manuals always get more power to the wheels. (Notice my sig ...)

niceguy

I had also wanted to try something like that ever since seeing those options for the Infinity and 300ZXs....And for some it may be worth it but as was mentioned, you'll always be about 5-8% down on whp because of DT losses...

Plus, 5 speeds are much more fun...I miss mine....Though my auto is fun too...there's nothing like feeling the adrenaline rush of someone trying to outmaneuver you in traffic and trying to pass you just as you stomp the accelerator and....get passed by as your auto gives you 3rd gear instead of 2nd....oh well.

Jeremy

KRMaxima21

I see what you're saying now. So say you do these tranny mods-

Stage 2 VB Mod
JWT TCU Upgrade
High Stall Torque Converter
Quaife ATB Differential

Even though thats about 3000 dollars right there, do you think that would get the same amount of power to the wheel as a 5-spd or at least in the same range? I would love to go 5-spd but I live in Queens NY and being that when I go to and get off of work is right at the height of rush hour a 5-spd would be muderous for me!! Im just looking to do something interesting on an auto tranny plus I think with these mods it would put alot less stress on an auto tranny if you go FI (something else I'm planning on doing this summer/fall).

njmaxseltd

iTrader: (19)

But the fastest 1/4 mile cars are automatics.

Tatanko

iTrader: (34)

It's Infiniti.

dr-rjp

iTrader: (4)

The REALLY weak link in the automatic is the torque converter. If I were to do any mods to it, that would be the first thing I'd replace/upgrade!

Chickan

iTrader: (12)

Correct but that requires heavy work to the automatic transmission. If you take two of the same car, same mods, and don't touch the auto tranny, the manual will always put more power down.

Now the fastest fastest cars in 1/4 are autos b/c it gets to a point where its impossible to shift that quickly, but since very few of us ever hit that, or even come close, your best bet is still an a manual.

Jeff92se

iTrader: (82)

I think in terms of a 4-gen auto tranny, you are correct. But with autos coming with 5-6 speeds now, an auto might actually be on par or faster than the same manual. If the auto has a lockable torque covertor, then it will put down the same power.

KRMaxima21

Jeff, say if you take a maxima with the same bolt-ons, but one is a 5-spd and the other is a auto w/ a high stall torque converter and VB mod do you would it actually be able to keep up with the 5-spd or even be faster?

RichMax

iTrader: (2)

I'm a bit more enthused about the CVT, myself... and Mercedes came out with a 7-speed manual, to boot, but I think Jeff and Tom are right. An auto with the same ratios as a comparable manual tranny and impeccable logic should stomp the manual....

Jeff92se

iTrader: (82)

The maxima (4-gen) has a disadvantage of having only 3 forward non-overdrive gears while the 5-sp has 4 (5th is overdrive). But the manual driver has to do the shifting. So there is a bigger margin of error on his part.

So the answer is "depends".

madnut

5spd is no big deal in traffic, you might think it’ll kill you but I have been driving in traffic here in DAMN Seattle for more then 4 years. You might think that Seattle area doesn’t have as much traffic but you’d be wrong, we are worse off because we have crappy public transpiration and tiny 2 lane freeways, with a 2-3 cars per family ratio. Anyway thats not the point, I admit you have to play with ur clutch alot but i wouldn’t trade for an auto even in traffic, nothing nicer then dropping into 1st or 2nd and jumping into that hole in the other lane, by the time auto figures out wtf ur doing you’ll be in someone’s car

a Quaife in a auto is a waste spend the money for a LSD 5spd tranny.

Yey my 100th post

4x4Max

iTrader: (12)

So getting a high stall torque convereter will make my car as fast if not faster than a 5 speed, since it loses most power on the torque converter? Where can a high stall torque converter be acquired?

WSU4runner

I agree with madnut. However, it's the Seattle hills that kill me with a 5speed.

Wouldn't it be more sensible to spend the $3k on 5speed conversion with LSD than trying to make your auto as fast as a manual? Just my .02

madnut

Hehe if your mean to your tranny on the hills its quite easy, the question is how often you wonna replace the clutch

ImmaSquashYou

iTrader: (7)

i thought that most of the fastest cars are slap-stick. u know, the ones that allow you to shift without the clutch needed. n i'm not talking about tiptronic seems to me that is a waste of money. put a supercharger in for like $3000-$3500 n u'll be much faster than a manual..

dr-rjp

iTrader: (4)

I'd love to have a Tiptronic, aka manumatic, if it is like the ones I've driven in the G35.

To me, it is as good as the true, clutchless manual they put in the Toyota MR2. No lag. No slipping. The shifts are instantaneous.

I don't know why people loathe them. They are certainly preferable to the unpredictable trannies they put in 4th Gen I30's.

Besides mine, I've driven three other 1998 I30's, so I know how they drive.

madnut

I dont like the way they are set up in a line, cant they set em up like the manual???

paultyler_82

iTrader: (1)

no, that's just the way true clutchless manual, aka SEQUENTIAL manual works. The tcm engages the clutch, matches the rev blip shifts the gear, and feathers the clutch in all much faster than a human could hope to, in fact, about as quickly as most upgraded VB autos would shift. But the TCM can only control the solenoids so much with out the system becoming inordinately expensive, which is why the gears are set into sequential order.

sterlingmaxima

iTrader: (16)

actually gated shifters can be extremly fast seen that setup on a dodge viper that was daily driven it blew my mind.

madnut

have u seen the new acura auto tranny design suppsed to sift "twise as fast as the human heart beats" well i figure thats 2 times in a second pritty sweet