We all know convertibles are slow due to their weight and they're all NA.
We all know automatic rotaries really suck and are slow (except 3rd gens which are decent especially with mods although they have their limitations).

I have a 91 Convertible automatic and I would like to add a few basic bolt ons to help it become "less slow".

So far I have ordered Racing Beat headers and cat-back and I plan to connect them with a custom straightpipe with a Magnaflow.

The car is getting a cone air filter, Racing beat pulleys, and spark plug wires.

What else can I do to enhance the performance maybe some small tricks that would help or bolt ons I haven't thought of.

To save you the trouble these are the things I am definitely not interested in and the reasons why:

Forced induction and porting - out of my budget and I need superb reliability
Engine swap - out of my budget and car has good engine
Weight reduction - there is nothing else I can do without
Wiring 6 ports open - lose low end torque, waste gas, small power gains

I wouldn't mind a 50 shot of nitrous if the engine can take it but I am concerned about the transmission. The car is a daily driver that has to be SUPER reliable. I think the current setup is ok just wondering if you know some good tricks I may have omitted. Thanks in advance for your time and advice.

By the way I estimate the stock performance at about 13 second from 0-60 mph and about 20 seconds in the 1/4 mile. Once the bolt-ons are in place it should improve to 10 and 18. I might be way off, just guessing.

Anyone have some concrete info on this? Can't find specs anywhere

 

Motor Trend magazine tested a 1989 Convertible automatic and got better numbers than what you are guessing. They tested 0-60 at 10.07 seconds and 1/4 in 18.06 @ 82.6 MPH. I assume this was with their standard "brake stand" launch.

 

That's really good news. Those are the #s I was hoping for once modded. Maybe I can get respectable"ish" times when I'm done. Could you describe the "brake stand" launch to me in more detail? Is it bad for the car? Thanks a lot.

 

put car in drive, hold brake pedal down, floor gas. The idea is to preload the torque converter, and gain a few rpm's on launch. It is harder on your trans/tc than a normal launch.

You could do a 5spd swap relitivly cheap, if you hunt real hard for good deals. Not only will it make the car quicker, but it will be *much* more fun to drive.

 

is the auto in good working order? not slipping or flaring at changes? if it is your fighting a loosing battle.

If the auto is good, Get a higher stall convertor made for it.
i've got a 3500RPM convertor in mine and it transformed the car (mine is turbo, so its on boost as i take off with a full stall). I have driven a 1st gen na 13b with a auto and 3000rpm stally in it and it too went very well too compared to the std stall.

FYI the FSM says the std stall is 2000-2200 RPM

 

Thanks for the info. The car is a cruiser, how would the stall affect milege? I would like to upgrade the tranny later to a badass one but stay auto.

 

"automatic convertible performance"

Did he just say those 3 words in context to each other?

See sig for your necessary mod list

 

your vert fc is the sexiest one evar

 

why stay auto?

 

:4000rpmstall:

 

wow THAT slow?? and rotaryerection!!

 

What did you expect? About 120 rwhp and 3800 lbs with no torque or holeshot.

Must be auto because I have to share the car with my wife who drives to work in traffic and hasn't learned stick yet. I guess I already got most of the bolt-ons that are available huh?

 

Kevin
You stole my line!, I have a GXL auto {for the wife} slow as hell But I also have a TII and a project A.E. I like to call them, "Yours mine and ours"

 

Where are you getting 3800 lbs? The curb weight of an 89 automatic vert is just about 3100 lbs. This weight is the car, all fluids and a ful tank of gas. You may be thinking of the GVWR which is the maximum weight of the car with 2 people and luggage.

 

Vert + auto = SLOW!!!

Do a TII swap! I want one SO bad, but I am gonna wait till I get stationed in Japan.

 

Yeah I wasn't sure about the weight but that's still heavy. In the owner's manual it says that a vert is lighter than a TurboII!!! ( It really does ) I do not understand this and I know it's wrong

 

91 convertible auto = 3115 lb
89-91 TII = 3003 lb

thats what it says here

 

Kevin Landers and myself will have 400 hp verts in a few months. So be carefully with coments like verts are slow.

 

We were talking about AUTO n/a verts tho

Of course nicely modded turbo conversion verts will kick ****, not doubts on that heh

 

Bukwild is talking out his ***. I may have 3-400hp, but little does he know I'm installing an NA engine back into his vert

IF you were serious about auto performance, I would say to find a 4.33 or higher rearend, run smaller wheels and tires, get a jspec auto turbo trans and engine, and haul ***