Hey everybody, I'm fairly new to the forum and have been reading quite a lot here lately and have learned a lot too, but I'm still gonna put this question out there for the hell of it.

I have an 89 Convertable with 167,000 miles on it and still runs great(knock on wood), but it just feels like it could be a little faster. I'm not a racer and I usually drive it pretty calmly and take very good care of it. I have too, its my daily driver and only means of transportation. I would just like to know that the power is there and not really use it, if you know what I mean. It does'nt have to be retarded fast, just a little bit more than it is now.

So onto the question, if any of you owned my car as a daily driver what are some of the mods you would do to it to give you that feeling of power I'm looking for? What are the gimmic things to stay away from?

Here are my limits as of this month. No more than $1,000. Car has to remain reliable. Car has to still do good on gas, right now I'm 99.9% City driving, stop and go traffic and getting 250 miles on 1 tank of gas. Not wonderful but not bad either.

Here is what the car is.(Just some codes that I thought would help in your knowing what you would be dealing with)

FEI-Base Suspention(replaced with KYB)
GM1-Rear Axle 2.59 Ratio
KC4-Engine Oil Cooler
L98
MD8-Automatic 4 Speed Transmission

Thanks for you help,
JBI

P.S. If anyone could explain the pros and cons of the different rear axle ratios, that would be fantastic.

 

A good used 3.07 gear ratio pumpkin usually sells for $200-$500 used. If you get lucky, and install it yourself. It is a great bang for the buck with little gas milage decrease.

 

With all due respect, your car's got 167K miles on it and it's your only means of transport and you have $1K to play with. If I were you, I'd bank that $1K and expect the repairs that will be needed in the forseeable future. Understand?

I'm not trying to put you or your ideas down. Just look at what you said and if you don't see my logic, have a good day.

 

if the car is your only car. I would leave it alone. Because when you start to mods the car, sometime ****ts happen and you can get stuck for a long time. My car got stuck for 6 months before I can drive it. From a 383ci LT1 install, to a supercharger install to a complete fuel system install and later to a turbocharger install and all.

 

A good 2.5"exhaust from the manifolds back w/hi-flow cats/mufflers really wakes the L98 up.www.performancepeddler.com, www.hotexhaust.com

What people feel don't work-
Air foil
MAT relocator
Power coupler'
High output coils
Hypertech chips

Look up 65Z01 (member)He has a list of all the free mods you can do to pick up your L98

 

Bank most of those $$ for when needed.

But you can still do some small mods that give some power adder:
-toss the frisbee from the water pump pulley
-install a 160deg T-stat & fan sw
-cut the lid and install a K&N air filter

Later, you can budget some funds into your "mods account".

If that $1k is really "exta" funds, also consider doing exhaust work, hi-flow cat & cat back.

What are your long term goals for the car? Come with the big plan and then implement each phase as possible.

 

Get a good tuneup first! Make sure you are getting the power you are suppose to have. Once that is complete than save, save, save and study the forum. A few months on here and you'll get the hang of what works and what doesn't. Good luck and welcome to the forum!

 

okay.. you have a supercharger AND a turbo on your car? i'd love to see the engine compartment.

 

No he doesn't have both, he had a supercharger and then ditched it for the turbo setup.

 

To all thanks for the feedback and advise. Re-reading my original post I made a typo and left out some info. The car has 147,000 not 167,000 opps! Still a high mile car, but still in excellet shape. Like I illuded to, I pretty much baby it. Fluids changed on sched. Brakes all around are brand new with rotors, shocks are new and car has a fresh tune.

The car came with an after market exhaust, not sure which kind, but it does seem to be louder than most. At least inside the car it is. It appears to only be redone from the cat back.

I had already planned on rebuilding the engine and transmission and have saved up half the money so far to do that. I'm expecting to have it done by Feb. of next year.

All I was really looking for were some small things that could be done now with the little extra cash that I had. Basically just to hold me over until next years major work. I love the car and my long term plans for it are to drive it until I can't drive anymore.

Thanks again to all for the links, advise, and welcomes!

 

Pete,

If I were to go with a 3.07 gear could I keep the same tire size on the car or would that have to change? The current size for all four are P275/40ZR17 Also, would I have to do anything to the transmission?

 

I've got an '89 coupe, and know exactly what you're talking about when you say you want "just a little more".

I definitely agree with some of the advice with respect to saving your cash, especially if your car is your only driver. My '89 WAS my only car (in fact, it's my first car) for a while, but now that I have another car that is my daily, I don't mind when things "break" because I can spend the time and money to fix it myself. But when the car was my daily driver, I needed it working properly at all times, so I didn't play with it.

But here's my suggestions of inexpensive (and in some cases free) things that you should do:
1. Remove the frisbee on the water pump
2. Disconnect the throttle-body coolant passage
3. Advance your base timing to 8deg (stock is 6deg)
4. 160deg high-flow thermostat
5. Cut-back spark plugs (use either a new set or the ones on the car)
6. K&N filter
7. Open lid air filter cover (you can cut the one on the car)
8. Competition Cams 1.6 ratio Magnum Roller Rocker arms (p/n #1418-16)
9. Port intake plenum (TPiS will do this for about $100)
10. Machine the throttle body to 52mm (TPiS will do this too)

Beyond these upgrades, you will be getting into some serious money and much more work. Things like the rear end, unless you do the work yourself, won't be cheap but can increase performance significantly (I'd stick with a Dana44 with either 3.07 or 3.33 gears). Another expesive but worthwhile upgrade is a high-flow intake manifold and large-tube runners. The exhaust manifolds hold alot of power potential too, so if funds allow it, that's another area to look at.

Performance upgrades to stay away from:
1. Throttle body airfoil (a joke)
2. Power coupler intake tube (another joke)
3. Adjustable fuel pressure regulator (the ECM adjusts for any increase in pressure so you'll gain nothing)
4. Pre-programmed performance chips (one should be custom-programmed for your car)

Some will argue that an adjustable fuel pressure regulator (AFPR) will allow you to 'tune' your car. But unless your stock pressure is on the low side or you have a custom-burned chip, the stock programming in the ECM will adjust for any additional pressure and cut the fuel back anyway. An AFPR is not expensive, so it's up to you if you want to do it.

That's it for now. Good luck with it.

 

You will need a speed sensor for a 3.07 rear. Also, you will need a different driven, and possibly drive gear in trans. Both these gears are easily changed and cost less than $25 for both. Tire size remains the same.

 

Agreed. I swapped a 3.33 into my 86 4+3 in place of the 3.07 and that really woke things up on the bottom end and even increased my top end. If you have an automatic the 3.07 will feel awesome. It will work well with engine mods later on. Definately the best seat of the pants mod for your car. Then depending on what you have left over if you do the job yourself you can add a few low cost engine mods.

 

I would go with a good aftermarket exhaust, which may not actually yield much more power, but will give you the illusion which is what it sounds like you're going for. You mention you have an aftermarket now, so you need to figure out what you got to start with. I got my Magnaflow from performancepeddler and I have to say, of all the mods I've done, that was my favorite, not the most effective mind you, but my favorite. Secondly, I would recommend a custom tuned chip to at least maximize the power that's already there. At 147K miles on your only daily driver, I wouldn't even mess with roller rockers or most any of the bolt-ons. Good aftermarket exhaust and custom tune and you're way within your budget.

 

Superram. Either just the plenum/runners or the base as well if within your budget. Port it a little bit. That will wake things up, and allow you to rev higher than 4500.

 

And if most of your driving is around town, the 3.07s might even help your mileage due to the car being able to accelerate at a given rate with less engine power. But at worst, I don't think you'd notice a difference in town. I've driven L98 cars with both of these ratios in them and the 3.07 makes a bunch of difference in how responsive the car is. I even retained that ratio when I swapped a D44 in my LT1 automatic because for my purposes, it's a great gear for an automatic. These cars have a pretty low first gear ratio in the tramsmissions to which makes them launch nicely with the 3.07.

For an econo exhaust set-up do this. People are always selling cheap or even giving away LT1 cat backs when they swap to an aftermarket system. It'll bolt right under your car with the appropriate brackets. Get some small, universal replacement or bullet cats, have a muffler shop cut your Y pipe into two separate down pipes, put the cats in and attach it to the LT1 cat back. You'll have a true dual system that will give you a noticable boost in power and should further help your mileage as well. I'll bet you can accomplish both of these mods, and if you can do the differential swap yourself, still have a few bucks left. Good luck.

 

Agreed. The 2.59 is a dog compared to the 3.07. If your looking for real seat of the pants vs illusion, go for the gear change first, then do what the other members have suggested according to your budget.

 

I know that some of these motors seem to last forever (wish my head gaskets made it past 50K), but with that mileage, I wouldn't do anything to "pep" it up until I made sure it was worth more than one shot at the stop light drags only to have something really expensive break. I'd start with a compression test and probably leak test each cylinder too. You might also consider having a transmission shop get some pressure readings, but that probably won't tell you anything if a couple of the clutches are on their last legs or a sun gear is about fall apart. Frankly, I'd keep the money in the bank for whatever breaks next or since you plan to keep it and rebuild it, why not spruce up some of the cosmetics? If the interior is worn, you might start with that. Paint? Some of the cheapo jobs can look good if you do the prep work. Wheels? Most of the '88 - '89 peel a little clear coat after 10 years - have them refinished or stripped and polished.

 

I have a 1996 and also a daily driver. With your high mileage, you might want to do headers or a good muffler system and maby a cold air or breather system OR a great tune up.

The later would be my first choice. Complete tune-ups increase your gas mileage and increase performance. Good luck.