What would be the best way to increase the acceleration of my car? I've got a 1980 Pontiac Firebird Esprit with the Buick 231 3.8 v6. It's a strong motor and is a stump puller at low RPMs but takes forever to accelerate. I'd like it to be a little faster when I accelerate.

First step is to make sure the car is in good working order...BEFORE you start to change stuff otherwise something will explode/fly apart/kill children. It will also probably cure the slow acceleration if there is a fault.

Check all your engine mounts, gearbox/transmission backlash, change the filters, check the HT leads for cracks, make sure your ignition system is working well (condensor, points, etc) get the carby reconditioned or clean the jets, clean engine grounding points, top up transmission fluid and clean its filters...and I could go on. Oh and change the fuel filter and make sure the pump is working as it should - no air being sucked in, etc.

Also adjust valve clearances and lap them if you fancy.


Before you make any real upgrades to the speed/acceleration, check your braking system to make sure it can put up with the increased load. A faster car will show up poor, malfunctioning brakes in the worst possible way.

If its a torquey motherfucker, and you dont care about top end, taller gears.

Seconded, stick a 4.10 Posi in there.

First step is to make sure the car is in good working order...BEFORE you start to change stuff otherwise something will explode/fly apart/kill children. It will also probably cure the slow acceleration if there is a fault.

Check all your engine mounts, gearbox/transmission backlash, change the filters, check the HT leads for cracks, make sure your ignition system is working well (condensor, points, etc) get the carby reconditioned or clean the jets, clean engine grounding points, top up transmission fluid and clean its filters...and I could go on. Oh and change the fuel filter and make sure the pump is working as it should - no air being sucked in, etc.

Also adjust valve clearances and lap them if you fancy.


Before you make any real upgrades to the speed/acceleration, check your braking system to make sure it can put up with the increased load. A faster car will show up poor, malfunctioning brakes in the worst possible way.

Engine mounts and Transmission mounts have all been replaced within the last 4-ish months. Carb was just replaced about 2ish months ago as well as plugs and wires. Brand new fuel pump a week ago, changed filters then. I know I need to repair my brakes first. I've got a leak in the rear brakelines, I just found where the leak is when I was changing my muffler. I'll have to check the Ignition system and the engines grounding points.

So the best bet for now, will be to change the gears? I don't even know the gears I've got now. It's hard as hell to find out information about my car online since its the 6 cylinder. I was talking to my dad and he suggested that I should put in a 3.93 because it'd give me a little bit better acceleration, but not hogging on the gas, but if I was looking to jump off the line to put in a 4.10.

The final drive raio IMO is only a fine tuning mechanism to help you get the most out of your engine - it desn't really swap acceleration for top speed etc unless you have a 1 speed transmission. I don't think you will get what you are after from a gear change unless you changed the engine for another and the old system is poorly matched.

Let me illustrate with an example.

When accelerating with your racier gears (eg 4.10 instead of 3.x), as you first start out, acceleration will be higher for a few kph, but you will have to shift at a lower speed, and then acceleration will be lower for a few kph, and eventually the revs will get up and you will be accelerating harder, again, than you used to at that speed, but then you will need to shift earlier, etc. The process continues and the losses fight the gains.

How optimal your gears are at a given speed is proportional to how close your RPM is to the power peak at that speed. Lower gears will have you getting closer, faster, as you first start accelerating, but they will have you shifting earlier and leaving the power peak sooner as well. There is also shift time and the fact that it will slightly 'focus' the RPM range you are operating in over the top end, i.e. the needle won't drop as far when you shift, but I don't think that change will be large enough.

The solution to 'I don't have enough acceleration' is usually:

a) More power.
b) Less weight.

and occasionally

c) less drag.

Pick one of the first two and go for it, I recommend 'a' because it's normally a bit easier and you won't sacrifice your comfort, and it's not like you care about fuel economy in an 80s firebird right?

The 3.8 is a really nice motor, but its not a powerhouse until you throw a turbo or a supercharger on it. For instance, the Series II 3800 has 240 hp, but that block has a FWD bolt pattern, so you will need a tranny bolt pattern adaptor. Isn't the bolt pattern the same as the Chevy trannies? Several Fiero shops sell transmission adaptors for fitting Chevy engines to the FWD transmissions: http://www.v8archie.com/v8Archie/Prod2.htm

I'm pretty sure they will work in reverse.

Smaller wheels, a well performing exhaust system from the manifold back, and a "better" cylinder head will all help with acceleration. Once you've done a few things, try and get to a rolling road to optimise your engine set up.

The 3.8 is a really nice motor, but its not a powerhouse until you throw a turbo or a supercharger on it. For instance, the Series II 3800 has 240 hp, but that block has a FWD bolt pattern, so you will need a tranny bolt pattern adaptor. Isn't the bolt pattern the same as the Chevy trannies? Several Fiero shops sell transmission adaptors for fitting Chevy engines to the FWD transmissions: http://www.v8archie.com/v8Archie/Prod2.htm

I'm pretty sure they will work in reverse.

I'd love to put a supercharger on my car, but I don't think there are any pre-made supercharger kits for the 1980 3.8L. I'd probably have to have it custom made. I don't know so much about a turbo. I don't like turbo lag. I'd like something that's kind of cheap, but just for a little bit of power. I'm not looking to spend a whole lot. A rear end swap wouldn't be too expensive. I've found a 4.10 posi for about $400. It'd be nice if that's all I'd need to get a little bit faster off the line. Also, the Transmission is the TH350, which is a chevy tranny.

If you get a properly sized turbo it's going to work better than if you get too large a turbo. If you recall the 1980 turbo Trans AM it had retarded turbo lag because it had a funny carb setup and the turbo was way too big. The Buick Rivieras and Grand Nationals didn't have that big a deal with lag.

If it's only $400, it's cheap and it works for what you want it to do. Probably will get better results with that than anything else that cheap.

If you get a properly sized turbo it's going to work better than if you get too large a turbo. If you recall the 1980 turbo Trans AM it had retarded turbo lag because it had a funny carb setup and the turbo was way too big. The Buick Rivieras and Grand Nationals didn't have that big a deal with lag.

If it's only $400, it's cheap and it works for what you want it to do. Probably will get better results with that than anything else that cheap.

My uncle has a 1980 Turbo T/A. I drove it when it was stock, and the lag was incredibly horrible. After he and a friend totally redid the turbo set up, this car was amazing. You'd put it sideways with just a tap on the accelerator. I'd love to find an 80 Riviera or GNX turbo, but the only one I can find is on ebay and it doesn't look that great. I've also not got the money to build up the internals at the moment.

If you have the choice, turbos are almost always the way to go. Do a bit of research beforehand, get the right parts, and turbo lag shouldn't be a problem.

The final drive raio IMO is only a fine tuning mechanism to help you get the most out of your engine - it desn't really swap acceleration for top speed etc unless you have a 1 speed transmission. I don't think you will get what you are after from a gear change unless you changed the engine for another and the old system is poorly matched.

Let me illustrate with an example.

When accelerating with your racier gears (eg 4.10 instead of 3.x), as you first start out, acceleration will be higher for a few kph, but you will have to shift at a lower speed, and then acceleration will be lower for a few kph, and eventually the revs will get up and you will be accelerating harder, again, than you used to at that speed, but then you will need to shift earlier, etc. The process continues and the losses fight the gains.

How optimal your gears are at a given speed is proportional to how close your RPM is to the power peak at that speed. Lower gears will have you getting closer, faster, as you first start accelerating, but they will have you shifting earlier and leaving the power peak sooner as well. There is also shift time and the fact that it will slightly 'focus' the RPM range you are operating in over the top end, i.e. the needle won't drop as far when you shift, but I don't think that change will be large enough.

The solution to 'I don't have enough acceleration' is usually:

a) More power.
b) Less weight.

and occasionally

c) less drag.

Pick one of the first two and go for it, I recommend 'a' because it's normally a bit easier and you won't sacrifice your comfort, and it's not like you care about fuel economy in an 80s firebird right?

I mean no disrespect here when I say you've made a few critical mistakes in your theorum; that steeper cogs are a good thing to look into if you want much improved acceleration, they will reduce your top speed, and it is more than likely they will also cause you to chew more fuel on the highway simply because you'll be motoring along at a different section of the rev range you would be with stock final drive, and that section may not be as efficient.

Like I said, there are more errors than I have mentioned, but most of the mistakes that created them have been brushed lightly. If you would like to dive into this deeper, respond and I will oblige.

I mean no disrespect here when I say you've made a few critical mistakes in your theorum; that steeper cogs are a good thing to look into if you want much improved acceleration, they will reduce your top speed, and it is more than likely they will also cause you to chew more fuel on the highway simply because you'll be motoring along at a different section of the rev range you would be with stock final drive, and that section may not be as efficient.

Like I said, there are more errors than I have mentioned, but most of the mistakes that created them have been brushed lightly. If you would like to dive into this deeper, respond and I will oblige.

You are right, they will reduce your top speed, I didn't quite think that through because all I meant was that the popular opinion that they swap top speed directly for acceleration was wrong.

You are also right that it will probably decrease fuel efficency on the highway since it will change where your car is revving, which can't be a good thing since stock, they are generally tuned to be optimum at highway speeds (though this wasn't a mistake of mine, since I never even brought it up ;) )

But as for increasing your acceleration, I believe I have already explained how I do not believe that this is the case for anything with more than a few gears.

I would be very glad if you could delve into this deeper with me, tell me why my not-helping-acceleration assumption is wrong, and tell me the rest of my mistakes.

I haven't had a good discussion in a long time, and my only regret is that I have to go in a few minutes, and will probably have to wait a few hours to read your reply :)

If you would like to dive into this deeper, respond and I will oblige.

I would be very glad if you could delve into this deeper with me

Not following through on your promises makes the baby jesus cry :(

I'd go for weight saving over more power, it'll help your stopping and cornering too.


o/t - I lost my job. Fucking economy.

I'd go for weight saving over more power, it'll help your stopping and cornering too.


o/t - I lost my job. Fucking economy.

That sucks mate.

Yeah it does. I got a new girlfriend too but if I can't find a job I'll have to go back to live with my parents. Life is fucking shit sometimes.

I'd go for weight saving over more power, it'll help your stopping and cornering too.


o/t - I lost my job. Fucking economy.

You're not the only one, mate.

I now went from a meager 12 hour work week (uni and tkd takes up most of my time) to a 3 hour work week. Fuck.

Will do burnouts for food.

Add some lightness

But as for increasing your acceleration, I believe I have already explained how I do not believe that this is the case for anything with more than a few gears.

I would be very glad if you could delve into this deeper with me, tell me why my not-helping-acceleration assumption is wrong, and tell me the rest of my mistakes.

I haven't had a good discussion in a long time, and my only regret is that I have to go in a few minutes, and will probably have to wait a few hours to read your reply :)


Not following through on your promises makes the baby jesus cry :(


I can't be everywhere at once, even if I'd like to be, and believe me my wayward posts in other forums don't show a purposeful lack of attention to this thread. I simply couldn't track it down. Hard to keep tabs on all these threads shimbarb.

http://www.totse.com/community/images/icons/icon7.gif

Because a week or more has passed since the last time we were discussing this, I hope you won't mind if I take it from the top, even though you have paid notice to flaws.

Post coming up, don't hold your breath too long.

I don't know if this would apply on big engines, but a lightened flywheel did wonders on my 2l N/A.

swap an GenIII Truck engine 4.8litre to 6.0 iron block and a These engines are cheap and plentiful at the boneyard. There are many aftermarket upgrades avalable on this engine and they do make decent hp and torque in their stock trim. And being in a lighter car instead of a heaver pickup truck/suv that engine would motivate you car pretty quick. it may not fit the older transmission but with a little thinking and metal work you can do it

http://i29.photobucket.com/albums/c271/geoff2005/misc/77502hh5.jpg

Post coming up, don't hold your breath too long.

:(

Best belt it out soon, we wouldn't want anyone doubting the legitimacy of this account...

If you know what I mean.

:(

Best belt it out soon, we wouldn't want anyone doubting the legitimacy of this account...

If you know what I mean.

For what it's worth, I've doubted the legitimacy of his account since day one.

For what it's worth, I've doubted the legitimacy of his account since day one.

Lol.

You would.

Lol.

You would.

You callin me paranoid? Ain't nothin' wrong with makin' assumptions and testing conclusions once in a while. Sometimes you join the dots and find out you're right, if you know what I'm sayin'.

You callin me paranoid? Ain't nothin' wrong with makin' assumptions and testing conclusions once in a while. Sometimes you join the dots and find out you're right, if you know what I'm sayin'.

So Jews were involved?