I have a 89 RS w/305 TBI. I admit my initial ignorance when I bought this car. I saw the dual exhaust and looked at the V-8 and was prematurely satisfied. I have heard a lot of people on this board complain about the inadaquacies of these engines, some more than others. I wouldn't have purchased this car if I did not seek performance. I admit it seems this car is more bark than bite.
My question is this: What is the best way to make this car as quick as possible?
I must consider the following factors as well:
-Must pass Exhaust emissions, visual inspection limited to vented gas cap and cat.
-Must get at least 15 mpg Hwy
-Must be reliable
-Future parts availability, should it need to be repaired
-I would like to keep the overall stock appearance from the outside of the vehicle
-Naturally aspirated, with option to go w/NOS or supercharger, etc. in the future w/o to much modification
-Cannot exceed $2500.00 total cost including wiring harness (if diff. required),computer, chip burning,modified fuel pump, etc. (excluding labor cost)

I'm looking for some honest real world numbers here. The more detailed the better.

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89 RS V-8

[This message has been edited by simon (edited January 21, 2001).]

 

Step one: Complete exhaust replacement. Edelbrock headers, Random Tech 3" cat, and Flowmaster 3" cat back made a huge difference in my car. That plus a 14 x 3 open element air filter and flow matched Turbo City injectors, are my only mods that I can say added noticable power. The JET chip, and MSD 6A helped throttle response. With just those mods I beat auto 305 TPI cars. You shouldn't pay more than 1500 for that if you have it installed. Do it yourself and you might have enough left to get rid of the worthless cam and/or heads. With decent cam and heads all bets are off, you'll be making REAL power.

 

Get a used vortec 350 from a junkyard and a 2" TBI unit, that's all you need for low 14's easy.

 

ANDY - how much HP are you making with the mods you listed - with, and w/o heads and cam.

Macgyver - If I followed your sugg. would I have to change the comp. and harness. Also, would all my emissions equip. bolt up the the Vortec? What year Vortec am I looking for and what vehicles came stock with these.


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89 RS V-8

 

if you look at my home page you can see a bunch of stuff you can do. everything is perfectly legal other than the cat eliminator. and i still get about 22mpg on the highway. about 12 around town.

lata
tim

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91 Camaro RS-LO3,Auto.
14.301 @ 94.39mph

Check Out The East Coast F-Body Nationals Home Page
www.geocities.com/njspeeder

My MAFB.ORG Home Page
www.mycar.net/mafb/registry/detail.cfm?id=299

 

NJSpeeder - what is your TB bored out to?
And where did you get your cylinder heads?

Thanks for the info, I plan on attending the E-town event.

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89 RS V-8

 

I still have stock heads and cam on a 200,000 mile old engine. Running at 240* due to a failed fan switch, I got 170hp at the rear wheels on a dyno run, roughly 200 at the flywheel. Based on my guess at the time of how badly the blazing hot air was hurting power, and later verified with 1/4 mile trap speed and vehicle weight, I'm making more at normal temps. Using the equations with trap speed and weight I'm making about 230 hp or so. Another sign that the heat caused big power loss: At the start of the run while still cool, it cranked out 305 ft/lbs of torque at 2500 rpm.

 

Andy, 200K, its about time for a new engine eh? Thats a true testiment to the durability of these motors though. Thanks for the info.

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89 RS V-8

 

You could always get a rebuilt 350. They are a little more than $1000, have warranties, are ready to go out of the box, and can be souped up from there. Of course, intstallation is not that cheap.

IMHO ditch the TBI, a carb will keep you happier. But the only F-bodies i've ever driven are Cross-Fire or Carb

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--Steve S--
1984 Trans Am 305 LG4, 5 speed
RPO codes point to Recaro version
Daily Driver, Flowmaster 80 Series

 

Go here to see what pablo had to say about the vortec combo. www.thirdgen.org/messgboard/Forum11/HTML/000565.html

I was told the early 90's, but again, that info from someone else's mouth.

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Godti
'89 Trans Am (Red)
305 TBI 5spd

[This message has been edited by Godti (edited January 23, 2001).]

 

The true Vortec 350, which is probably what you want only came in 96-98 Chevy and GMC Trucks, Yukons, Tahoes etc. It never came in any autos. 95- back 350 were TBI 350(LO5's) which were not nearly as powerful as the Vortecs. The LO5's had a swirl port head similiar to the L03 only with bigger combustion chambers, and have all the same shortcomings as our engines, only they were a little more powerful due to the cam, and the fact that it was a 350. I would go with a Pre-87 350, which you can hook your TBI to or a Vortec, but I wouldn't build a L05 unless you cahnge the heads JMHO

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82 Z28 350, Ported #882 Heads, Performer RPM cam and intake, hedman headers,650 Demon carb,
Trans: Turbo 350 w/ 4000 stall -- Rearend 7.5 w/ Richmond 4.10's, Auburn Minispool
Best ET: 12.52@107.2
Future plans: Dart headed, Roller cammed 383 in early '01


89 RS, L03 305, Hypertech Chip,cat delete, Dynomax exhaust,K&N open element Filter,160 stat, MSD coil --Trans:700R4 Corvette Servo -- Rearend: 7.5 GM 3.42 w/ posi-lock
New Best ET: 14.91 @92.9
http://www.bassettracing.cz28.com

 

i got the heads from summit, they are a regular shelf item, straight out fo the edlebrock catalog. i will try to find the part number for them. they are 2.02/1.60 valves with a 60cc chamber. it's either a 185 or 195 intake port(can never remember which one, but i think 185)
my tbi is not actually bored out at all. i did a bunch of work to the top of it so it flows a ton more air. i am in the process of writing a tech article about it when i have time between work and organizing the gathering.
i'll get ya that part number though.

lata
tim


------------------
91 Camaro RS-LO3,Auto.
14.301 @ 94.39mph

Check Out The East Coast F-Body Nationals Home Page
www.geocities.com/njspeeder

My MAFB.ORG Home Page
www.mycar.net/mafb/registry/detail.cfm?id=299

 

NJSpeeder, what happened to that p/n?

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89 RS V-8