Hi Knight Rider enthusiasts and David Hasselhoff luvers!
I've tried searching for this but no luck.
I have an -89 GTA with an LB9 engine, T5 trans and Warner rear. Has about 108000 miles on it. It does not have dual cat option, but the single cat it had was deleted, and replaced by a straight pipe. Don't know if this changes output amount or not...? Otherwise the car is stock.
I've tested 0-60 and it's approximately 8.4 seconds. Seems a little high to me. Although I guess wear and tear of parts over the years would slow it down a bit, heh!
What acceleration times and top HP:s was this car supposed to have?
Or what has your own stock car with roughly the same options?

 

2.77 rear gears? 3.45? It makes a little difference.

 

From the factory they were given a rating of 230hp and 300ft lb of torque. But since you didnt have the dual cat option it prob had 220hp and mayble alittle less torque. But since youve now taken off your cat, you prob would be making more than 230 at the crank (NEW) with 108k theres no telling how much it has now.
Id say with the manual back then the car should have run in the mid 7's to 60.

 

For his 5 speed LB9 the only optional gear ratio was a 3.45 with a borg warner rear axel.

p.s. Bad*** bird man, paint looks awesome!!!

 

Mucho gracias for the info man and thanks for the compliment on the paint, it's still original!!
So then 8 + something seconds isn't so bad I guess. I know there's alot of things that are worn on it so maybe if I in the future change those it will improve acceleration. I've recently put in all new ignition parts like sparks, cables, cap and rotor. Also new airfilter.
But for instance I know the injectors are kind of old, as are the vacum hoses (don't think they leak though). Could these things be bad?
In my opinon the car doesn't have so much low end torque or power but on the plus side it has alot upwords to 4500 rpm. Anybody have an explination for this? Could it be because of the deleted cat shifting the power higher up or can wear or malfunction of a specific part cause this? Ofcourse I can't be sure of knowing if power has actually been shifted up or if it just has lost from the lower end.

Please anyone tell about your experiences in what parts usually get worn over the years and cause power declines in your similar to mine cars. Or whatever improves acceleration. Preferably things that don't require opening the engineblock itself. Working on a limited budget

 

Your motor should scream from 2700-4700 RPM.

Just do some basic TPI mods, get a clutch and P/P up to the task, and learn to properly launch the car. I had, at one point in time, a 88 Formula LB9/M5, and it was a pain to launch.

Read the many stickies for basic mod ideas. AFPR, and a home made CIA are good places to start. Go with a 3 to 3.5 inch catback, headers, a new base (read: Accel) and a set of worked over SLP runners, and you will have a whole new beast. Heads and cam would be great, but I don't know how far you want to go with it, or how much money you have to work with....

And finally, yes, after nearly 17 years and 108k miles, those injectors are probably getting dirty and slow. New ones might not be a "Requirement" but they sure couldn't hurt.

 

Ya man, do your injectors that will improve it alot. When I did it to mine it made a big difference to my acceleration. Also make sure you check your vacuum hoses, they make a big difference if theyre leaky especially in TPI engines. Id suggest doing a few free mods.

 

If you haven't done it already, do a good tune up on it. Plugs, wires, cap and rotor etc. I'd also suggest replacing the O2 sensor, and put a bottle of fuel system cleaner in it next time you fill up.

 

CIA is from America, He's in Finland! j/k I had to do it.

 

Thanx for your input GOY!!
Yes it definately screams in those rpm:s.

What do you mean get a clutch and P/P up to the task? English isn't my native language I know the clutch has been changed a couple of years ago so it should and feels to be in great shape. Yeah launching the car can definately be a bit tricky... keeping it from spinning the wheels too much and rather aim for traction is hard. By the way what is all this talk about M5:s I see around.... thought the name of the trans was T-5...??
I'm thinking of having the injectors atleast cleaned thoroughly. If I afford it replace them intirely.

 

Is that only a Firebird thing ? Just because my 1989 ROC came with a LB9 5 speed with 3.08 posi .

 

I don't know if it is. Is your 3.08 posi also Borg?

 

nope 10 bolt ( 26 spline axles)

 

This is probably one of the best things you can do in a high mileage car if it hasnt been done in a while. And I am not talking about that STP crap. What you need to do is get a 16oz can of Seafoam and dump it in your gas tank right before you fill up next time.

My engine was getting really crappy mileage after running rich for a long time due to a severe vacuum leak as well as some other things. After I got all those issues adressed, I had only gone from about 10mpg to 13mpg. After dumping in a can of Seafoam, I was back up to 18-22mpg city/highway.
It wasn't just a placebo effect either, I legitimately checked these numbers by dividing miles driven by gallons consumed when I filled up the tank at the same gas station I go to every time. And I always pound on my car, so it's not like I babied it after the Seafoam.

So even though I can't prove with rock hard evidence power gains based on extreme mileage gains....I think it's safe to say that it can only help. If that was enough to clean out all that crap that builds up on the valves, in the injectors, etc, it has to help performace.

 

P/P is usually Port & Polish, the smoothing and somewhat enlarging of the intake and exhaust ports both in the heads and the intake manifold/plenum. M5 just means Manual five speed. The T5 is an M5, the fourth gens for example had M6s which were T-56s. Its the same for Autos, A4s (700R4, 4L60E) and A3 (THM350 & 400) etc.

 

Thanx for clearing that up MattODoom!

I've been thinking of doing something to the runners and TB opening...maybe just go with bigger parts since I know thery're available rather than porting and polishing the originals which seems like a difficult thing to do. Or is it worth the sweat? I mean I could just as well comprimise my spare time by working overtime at my regular job and thus get the money for new parts anyway.
Also if i remove the runners from the plenum do the gaskets need replacement after this or are they still usable?
Do you mean the exhaust manifold can also be ported? How much power would that add? And how much would this porting and polishing increase the risk of these parts just ending up ex- or imploding on me since they weren't built for this?

 

Theoretically you could port the exhaust manifolds, but I was only refering to porting the heads and intake manifold. Along those lines however, one of the first things that should be done, really to any SBC, is a decent set of headers and Y Pipe. I would not buy a new throttle body just yet, the stock 48mm flows well enough past all the other parts of the TPI. You should look at either some SLP runners to port or some Arizona Speed & Marine runners.

The gaskets will need to be replaced, I made my own from some gasket material (Felpro).

 

Mr . gasket part number 152 is for bigger runners and base. I must for bigger runners and base. I myself like the edlebrock runners the best . They have bigger ports than the SLP . With LOTS of room for proting and siameseing . I did mine 4"in