[V8] gearbox swap questions

[Scott Justusson]

 Problem...  We are talking about a resto-resto mod, not incorporating a CAN bussed transmission.  The real problem is the OP speaking to gas mileage as a motivator....  The spreadsheets kill that immediately, even if you don't count your 'time'.  I go through this all the time.  By the time you do this swap, you could have done nothing and paid the gas mileage and Premium>regular respective differentials, and still had spare cash 5 years from now.  OR, just take the budgeted dollars, and go buy a car that doubles the resto-modded mileage.  That's the reality.  But all is not lost!

Change the 'want better mileage' to, I just 'want to do it', the playing field changes, and a lot.  This is where the 6speed suggestion sits well vs incorporating the 5speed auto.  A 6 speed conversion with a .62 overdrive 6th gear, should yield a decent fun factor and up the mileage on a v8 equipped D2 or C4.  Since I'm currently involved in doing exactly that into a C4 with a v8 conversion, it should be interesting to get real results from that idea.

The biggest issue we face as Audi Automatic owners is, the lack of tuners, which leads to lack of tuner desires.  My last few weeks helping investigate driveline options in a resto-mod 69 mustang fastback, shows us Audi owners are massively challenged to accomplish infinite options.  Fords and GM products have standalone ecu's for Automatic retrofits, that include cruise, sport, lockup, and kickdown programming that make our 3 position v8 Autos look primative.

Me, I'm just not a fan of manuals in big cars, because they just don't belong IMO.  Back to back drives with a 5speed 4.2 conversion vs a 4spd auto 4.2 demonstrates this too clearly.   With the chip added to my 4.2, my daughter could put her foot to the floor and take the best shifted 4.2 5speed conversion to 100mph.  

I like the HP24 for all that it is, especially to the 4.2 cars.  It's well matched to the engine, you can slap stick it if you are feeling the need, and in sport mode it will hold to redline in every gear.  And for a battle tank, it can go to the track and hold its own against some pretty impressive newer cars, btdt.

Gas mileage is the eye roller here....  IMO, you want gas mileage, you are driving the wrong car.  Buy a 91 200, you will get 27-29 highway with the same chassis as a v8 with a 5speed, btdoingt.  And you can buy one for less than the price of the HP5.  Or, take the 20vt engine and plunk it into a 4kq chassis for the same total investment, btdt2.  With 2.5 bar PT, I get over 30mpg highway, and the fun factor rowing those gears, is a resto-mod of the first order.

My .02

Scott J
91 v8 Auto
92 v8 Auto ABT Chipped
91 200tq
87 4ktq 20vt 2.5bar
84 Urq RS2 Project
83 Urq

 

 

-----Original Message-----
From: Professor GT gmail <CavalloGT at gmail.com>
To: V8 <V8 at audifans.com>
Sent: Fri, May 24, 2013 10:56 pm
Subject: Re: [V8] gearbox swap questions


Oh boy, here we go!

First off, ALL manufacturers these days are using communication links like CAN 
BUS, to tie EVERYTHING together. The VW Phaeton (a real fart in church) had 
something like 60 control units all talking to each other over CAN.
There are many benefits, and I can go on for quite some time about this (my 
J1939 datalink presentation is over 140 slides), but the drawbacks are mainly 
centered around Servicability issues.

So, the point, forgetting about any possible hardware issues, is the lack of 
flexibility with respect to vehicle integration, or installing and then properly 
controlling that trans in a vehicle it was not designed for. That said, anything 
is possible, but practicality has to enter into the equation also. Bottom line, 
not worth it!

Secondly, on the automatic versus stick debate: there is NO compelling reason to 
switch from an auto to a manual Trans, other than if you enjoy playing with a 
clutch pedal and a shifter, PERIOD!

Better fuel economy with a manual? 
NOT! 
Maybe years ago, but with today's electronic controls, automatics are far 
superior.

Vehicle Control? See previous response!

Pulling power? That thing called a torque converter kicks a clutches ass hands 
down every time! See previous response!

Driver Comfort, and ease of operation?
Do I even need to ask?

And with all this in mind, when applied to larger vehicles the case is even more 
compelling for automatics! Any trucker who buys a new vehicle with a stick is 
just kidding himself! The ONLY reason a trucker would prefer a stick is because 
of the Neanderthal effect. It has been proven over and over, beyond a shadow of 
a doubt that an Allison automatic is far superior to any manual or automated 
manual ever created.

Okay, now that I got that off my chest and put those facts out there, before you 
call me a hypocrite, let me say that I have my V8 5-speed for the novelty and 
rarity factors, coupled with the fact that its just fun to drive! That is at 
least until I hit traffic!
Having an original factory V8 5-speed is cool, and to the automotive purist 
represents the best that the Europeans had to offer in its class, at the time.
I spite of the traffic I have not grown tired of it, and view it as a blessing 
for the long weekend commutes I've been doing since last Fall...........but an 
automatic is in the wings to replace my 5-speed as a daily driver so I can save 
the stick for special occasions!

Now I feel much better that my rant is done! LOL



Thanks,

ProfessorGT