Alright, I'm new to F-Bodies, but this isn't my first car so i'm not completley lost. I just picked up an 89 GTA (135K miles) with the 5.7 TPI and a 700R4 among the rest of the WS6 package.

My mindset now is to put together a tight handling, nice braking mid to low 13 second car. Of course, i'll probably want to hit the 12's in time, but that's a while off.

So far i've been fixing what needs to be fixed...made sure the brakes were good, air and fuel filter, pulled a few plugs to make sure they were alright among other odds and ends that I come across.

I've replaced the stock springs, struts and shocks with Hotchkis and KYB respectivley and I'm wondering what to tackle next and also what the upcoming 'winter project of the year' might entail.

How do you guys recommend approcaching this? I'm aiming to build the car first and then put in the nice engine as long as it holds out, but what where do I start?

It's got a nice Y-pipe (SLP? not sure but it is 3" at the collecter), dual cats and a Flowmaster cat back already. Tires are good and bushings look to be in good health. Tranny is a bit sloppy but it shifts and the engine is running strong enough for now.

Just looking for a head start more or less.

 

For suspension, PST poly graphite front and rear kits. Solid trailing arms and panhard rod, Poly trans mount, new GM rubber engine mounts, new upper strut bushings and to top it off...subframe connectors.
This will get you a nice tight suspension and go well with the shocks and struts you already bought.

For the engine, a set of SLP headers to go along with that Y pipe would be nice, you seem to already have the cat back installed. Nest is improving air flow on the intake side. You need to know if you are going to keep the same hood or go with a ram air hood in the future before you invest serious money into the intake tract, but a good cold air intake system would help, a set of high flow runners and high flow manifold base (or a holley stealth ram setup, Accel super ram or the like) Basically anything to improve air flow into the engine and would be transplantable onto a new engine when the time comes.

 

Ok, you mention solid trailing arms which reminds me of a few things I was wondering.

First off, I saw tubular A-arms for under $200 somewhere, but I'm wondering how much of an improvement they'd be. Same goes for the trailing arms as from what i've read about Chevelles and G-Bodies, these aren't a problem on most street driven cars.

As for the panhard bar, is there a noticeable difference from stock? What about the torque arm?

The intake.... Yes, I do plan on throwing some money at getting the engine to breath better, but with the high mileage motor, i'm looking for efficiency before power for now as I've seen 'healthy' high mileage motors come apart once more HP is getting generated.

I'm curious how beneficial a cone filter behind the headlight along with aftermarket tubing kits are. I'm leaning towards a cowl hood but don't see any easy way to plump to get the most out of the high flow and retain my MAF which I would like to do so I'm still undecided. Nothing personal to those who have them, but I'm not a big fan of the ram air hoods.

These are all things I plan on doing searches on as time allows, I'm just fired up over this car and I'm curious what the general opinions are on these things before I start digging deeper. I apologize if I'm raising dead-horse issues.

 

get a rear disc conversion kit from baerclaw. or is it bearclaw. can't remember. will do a great justice for your braking. maybe upgrade your master cylinder and run larger brake line if you can find front and rear disc calipers with larger fittings. if not it's okay. just the rear disc alone should do justice for you unless you want to really get technical. you could always put B-body front discs on. it will take some contol arm modification. I know that someone makes a conversion kit for B-Body brakes. B-Bodies had the largest front disc that gm ever made. I think it was like 9 or 10 inches. That will definately improve your stopping abilities.

 

Tublar A arms for under $200 is a pretty good deal. With those and solid trailing arms and panhard rod your car will handle like it is on rails.
IMHO, the torque arm GM put on there is a good street piece, if you plan on racing regularly you might want an adjustable torque arm to get the best pinion angle and rigidity for hard launches.
A cone filter and less restrictive ducting won't be an immediate gain, this sis something you'll notice more with a better flowing intake base/runners and ported plenum. These things aren't just about power, they also make the engine more efficent. And when the time comes to replace the engine, they can be moved to the new engine.

 

What I should have asked about the aftermarket intake, is how much power does it take to require the relocation of the filter element? It just doesn't seem that the spot behind the headlight is going to get enough air to feed a heavy breathing engine. I realize i'm not going to free up 10 HP or whatever it is companies advertise, I'm just a bit taken aback that area does the trick.

As for the rear brakes, this car came with them from the factory. I'm not sure what the rotor diamater is on the front or rears, but the last chevelle i had was 4 wheel manual drum so this is like a little slice of heaven for me! I'm sure i'll at least upgrade the calipers when the time comes.

Thanks for the start guys, i'm off to start reading up on subframe connectors as I'm thinking that should come first.

 

It really isn't a question of how much power you should be making to have to relocate or change the inlet, it is more a question of breathing. With the ported plenum and high flow intake/runners you'd need to put in a less restrictive inlet tract to take full advantage of what the other parts can flow. The options for a Firebird in location of the filter element are kind of limited, very little space under there with cold, free flowing air, add to that the fact that you have a MAF sensor and the choices become more limited. The camaro really had about the best inlet tract for MAF set up but that won't work on the firebird. For the best flow you'd need a 90-92 speed density system and then you could use the ram air hood with functional scoops, direct shot into the throttle body.
If you concentrate on suspension mods first and get the car nice and tight, you'll be much better off and probably happier when you install the fire breathing high HP engine later.

On the brake issue.. the stock 4 wheel disk brakes work fine (look into getting the recall kit for the rears), the best thing you could do for the brakes at this point is new rotors (the factory ones have already been turned probably) and a set of Earls braided steel brake hoses (This will greatly improve your braking), then bleed all of the old brake fluid out of the system untill the fluid coming out is nice and clean.

 

you could always totally renig the induction system using PVC pipe. I did it with my 6. it was a little easier because there is more bay room in front of the motor. V8 i think may be to cramped. The car is TBI right? If it's TBI or carb'ed throw a ram air hood on it and forget about the induction system.

 

I've seen some nice intakes that people have fabbed up and I might make the effort, that's a hell of an idea.

The car is TPI with MAF which Morley pointed out, makes things all the more difficult. Got plenty of material to read but I'll be sure to post back and let everyone know how it works out.

 

does it have a split induction snorkel like this.

 

no, that's a camaro induction. I have a tube from the throttle body that goes towards the passenger side with a tube style filter that goes behind the passenger headlight. That's what my question was about b/c I don't see how that can supply enough air but if they say it's so, then i'll believe it's so.

Thanks for you help and suggestions.

 

Well, it ain't so, not really. The firebirds/ T/A's with the same engine as the camaro were rated at around 15 hp less because of the restrictive inlet tract.

 

I agree with Morley. The mods you do now need to be planned with a future engine in mind. Don't just go and start throwing money at everything. Start with the suspension and make sure that everything is up to par there. Then the exhaust and intake systems. Maximize these systems so they will supply your future setup. Maximizing these systems will give you some horsepower and should not cause your engine to take a dump. Also I would do a compression check of the motor. This will give you a good indication of the internal condition of your motor. This is the way I have been working on my 91 rs. All of the suspension mods and exhaust mods, then the other stuff. You definately are on the right track, so keep plugging along and good luck.

 

I am an idiot. forgive me. you can do what my buddy did...it was crazy though. He dropped the induction down along side the frame by the tranny lines and made it pop straight forward. worked decently but was too close to the ground. needless to say, traintracks made history out of that little idea. if you could figure a way to gain ground clearance let us know.

 

Phil,

With a couple strips of 12 or 10 gauge plate, you can box the stock LCAs on the lower edge to minimize lateral flexing. While maybe not as "pretty" as a pair of aftermarket LCAs, they should be as functional with polyurethane bushings installed.

On the other end of the car, the lower swingarms themselves aren't as much of a problem as the bushnigs they are mounted on. Also, the upper strut mounts and the subframe rails can allow a lot of steering loss. Reinforcing the left rail where the steering gearbox is mounted, installing an upper strut tower brace and/or lower frame rail brace (Wonder Bar) can really improve feedback and compliance. The upper strut bushings themselves are a point of wear on a car with that mileage, and should be inspected at least.

The factory driveline torque arm is somewhat adjustable, just not easily. It's a lot more time consuming to alter the bolt openings and mount the axle snout at the desired angle. The aftermarkets are just a lot more easily adjusted.

Even if you don't end up with a 9-second car with top-cracking launch torque, you might take a close look at those gaps between the front subframes and rear body channels. Subframe connectors can help not only for those zero-to-whatever power explosions, but stiffen the entire body for better overall handling and feedback.


Once you get the body and chassis ready to run the canyons, you'll want the engine to deliver the torque to get you out of the curves and higher RPM power to make time in the straights.

The MAF is not so much of a problem as the plenum itself. The throttle body itself has less flow area than the MAF. The 70mm MAF (Bosch 14094712) has a free area of = 5.965111 inē and has been flow tested and rated at 544 SCFM @0.01"SP. Compared to the stock and aftermarket throttle bodies, the MAF appears to be just fine:

OEM 48mm throttle body = 2.3323786 inē per bore, minus plate and shaft area 4.6648 inē TOTAL

52mm throttle body = 2.7799564 inē per bore, minus plate and shaft area 5.5600 inē TOTAL

58mm throttle body = 3.5243652 inē per bore, minus plate and shaft area 7.0487 inē TOTAL

And if the throttle body appears restrictive, the area just behind the throttle body is typically cast so roughly that there are significant restrictions to be removed. The runner openings are usually not matched well to the runners themselves, so the resonant tuning that the factory engineers intended is almost cancelled by the frugal methods of the factory accountants. A little attention at the plenum transitions can liberate more flow and better resonanace to make torque at lower RPMs.

Porting the plenum and matching the runner openings well are low cost methods for improving the system. It helps a little on a 305, but is really more significant on the L98. Regardless of whatever modifications you might do with your engine, if you are planning to keep the TPI, opening the plenuym will be worthwhile.

The Pontiacs do suffer a little more intake tract restriction, but that can be addressed as well. If you have the round, "garbage can" air cleaner assembly, its really easy to liberate a little more intake air flow. Whatever you do, DON'T cut holes in the outside of the housing, since the filter is an inside-out flow type. Cutting holes in the can will allow unfiltered air into the engine. A cone filte may allow heated underhood air into the engine, which might negate any flow improvements of the intake. Besides, K&N makes a replacement filter (890) for the "garbage can" air cleaner.