1989TransAm

Hey guys, I've been reading messages on these boards pretty much everynight, and feel that I've gained more knowledge than what i started out with. i want to do some mods to my car, that improve acceleration...basically i just wanna burn rubber when i floor it, i'm not too concerned about top speed, i don't plan on going 120mph in this car. i've found a website that helped me out a lot, and i compiled information from that site to help me in my process....what do you gusy think..are these mods worth it to get the results i'm looking for, or can i do less mods, get better results, at the same price ($1500 max.) Thanks always for your help.

TBI Mods
Modification: Item Name: Part Number: Location: Price:
Exhaust:
High Flow Cat: Dynomax Super Converter (2-way) 3"-18"long #289-15147 http://www.jegs.com/cgi-bin/ncommerc...92&prmenbr=361$139.99
Ignition:
Spark Plug Wires: MSD 8.5mm Superconducter w/ 90° boots #MSD-31229 http://store.summitracing.com/partdetail.asp?part=7426 $69.95
Ignition Coil: MSD Blaster Coil #MSD-8226 http://store.summitracing.com/partdetail.asp?part=9030 $38.95
Cap: MSD #MSD-8426 http://store.summitracing.com/partdetail.asp?part=8898 $21.39
Rotor: MSD #MSD-8427 http://store.summitracing.com/partdetail.asp?part=24236 $6.99
Spark Plugs: AC Delco RAPIDFIRE (.045" gap) #CR45TS
Rear End:
Gears: GM Motive 3:42's N/A http://www.gearsareus.com/_private/G...ff/gearsgm.htm$170
Differential: Auburn GM 7-1/2'' & 7-5/8'' 10-Bolt, 26-Spline 109-542057 http://www.jegs.com/cgi-bin/ncommerc...20&prmenbr=361$329.99
Engine:
Air Filter: K&N 14 x 3 Open Element Assembly & Element KNN-60-1264 http://store.summitracing.com/partde...sp?part=779 or Autozone
Thermostat: 160° Hypertech Thermostat HYP-1000 http://store.summitracing.com/partdetail.asp?part=10376 $7.39
Computer Chip: Hypertech Thermomaster HYP-128962 http://store.summitracing.com/partdetail.asp?part=20774 $121.95
TBI Spacer: .5" Spacer #635-500 http://www.turbocity.com/TBIPowerMain.htm $42.95
Injector Spacer: TBI Spacer #630-105 http://www.turbocity.com/TBIPowerMain.htm $19.95
AFPR: Adjustable Fuel Pressure Regulator 9-13psi #630-130 http://www.turbocity.com/TBIPowerMain.htm $69.95
Fan Switch: Hypertech Cool Fan Switch #4026 http://store.summitracing.com/partdetail.asp?part=10421 $42.95

Approx. Total Price: $1,082.40
excl. Tax & Shipping

1989TransAm

please let me know if these mods would work, i'm a little confused with the differential...i have a 89 TransAm TBI

vjo90RS8

iTrader: (1)

for the same price of the auburn posi, you can probably get some 28 spline axles and an SLP take off posi, just another option to throw in there. search "slp posi" if you want more info.

tbfirebird

dude check ebay thats where ive found alot of stuff.

v8unleashed

iTrader: (3)

i wouldnt ONLY do the cat, do the whole exhaust or do nothing, unbottlenecking only the middle part isnt gonna help a whole lot

the ignition stuff is good for a tune up but not gonna give you a substantial power increase

get the slp posi instead like he said, 100 bucks

lots of people say the chips are crap but personally i noticed a huge difference, i dont think its a bad idea

you'll need an installation kit with new bearings and gaskets for the rear end. that's $100.

the gears are your best mod on that list, then you should do FULL exhaust from headers on back. then the ultimate tbi, the spacers, and open element. those things will help you more than everything else put together.

25THRSS

If you say ure not really concerned with top end and you want to burn rubber or make it mostly a stoplight racer 3.73 gears would be better I think.

tbfirebird

why not somehting in the 4.?? or better yet 5.??

25THRSS

Do they even make a 5.?? gear ratio for the 10 bolt. I dont think they do. Besides, that low of a gear will take you out of your power band too quickly and you could run out of gear at the end of the 1/4.

vjo90RS8

iTrader: (1)

come on now, 5.xx gear ratio, i hope you are joking around. Also, try ebay for some of the stuff, tntperformance sells turbocity TBI spacers for 30 and their injector spacers for only 15. You can also make your fuel pressure regulator adjustable for free and it will be exactly the same as the turbocity version.

also www.tbichips.com sells some tbi performance chips for only 30 bucks, you might want to check them out before decided to spend over 120 for the hypertech one.

1989TransAm

vjo90RS8: if it's for the same price, why would I do that, is the 28 spline better than the 26, how so? thanks for the cheaper chip, is there a performance difference between the 2 chips?

tbfirebird: thanx for the advice, i'm a bit wearie of the auction stuff, but we'll see

v8unleashed: I already have flowmaster exhaust, since i'm on a tight budget, would i see more gain with upgrading the cat or adding new headers? how is the slp posi better when i would have to replace the axle as well to a 28 spline?

does anyone see anything on the list that i should take it cause it won't help at all? thanks again everyone for your input

v8unleashed

iTrader: (3)

your best options

cat + headers

headers + no cat

leave it alone for now

just the cat isnt gonna help a whole lot

r90camarors

Do not waste your money on the hypertech chip. Until you get winaldl data, don't even worry about a chip. After you get data, go to tbichips.com and brian will hook you up.
definetely go with at least a cat back system, but perferably headers and y-pipe. Spend the extra $$ and get the headers ceramic coated-it's worth it.
If I remember right, some '89s came with 28 spline axels-you would have to check your VIN to find out, though I'm not sure at which point they changed. The SLP unit works great btw.
Instead of buying stuff from turbocity, use the money and buy an intake manifold. Depending on what your overall plans are will determine what intake to go with. Perform the ultimate tbi mods and go from there. Look into Turbocity stuff after you have your engine breathing and performing better.
As far as ignition goes, it's nice but not needed until you do your other mods first. The msd coil works really well, especially with the msd 6A, but it's not needed until you get your engine breathing past 4,500-5,000rpm.
I would also suggest underdrive pulleys if you can find them for cheap. But at full price they're not really a great mod. If you have an automatic, shift kits are really nice especially with 3.73s. If your lookin at turning tires, then you will really love the shift into second. If you have a standard, think about a short throw shifter. Best of luck with your project

vjo90RS8

iTrader: (1)

the 28 spline axles are a lot stronger than the 26 spline ones.

burnouts4ever

TBI Mods

Good Idea, its easy to do

High Flow Cat: Dynomax Super Converter (2-way) 3"-18"long #289-15147 http://www.jegs.com/cgi-bin/ncommer...92&prmenbr=361 $139.99

get a catco if you are gonna use a cat

you are also gonna need headers and a catback exhaust

Ignition:

Dont worry about it yet
Ignition doesnt =hp in my book

Rear End:
Gears: GM Motive 3:42's N/A Gears

Get them off ebay or classified's here

get the slp posi carrier as well

Engine:
Air Filter: K&N 14 x 3 Open Element Assembly & Element KNN-60-1264 http://store.summitracing.com/partd...asp?part=779 or Autozone

Thermostat:

I wouldnt buy into a hyptertech thermostat


Computer Chip: Hypertech Thermomaster HYP-128962 http://store.summitracing.com/partd...asp?part=20774 $121.95

Wait off on a chip its not really worth it, advancing your timing is more effective.

TBI Spacer: .5" Spacer #635-500 http://www.turbocity.com/TBIPowerMain.htm $42.95
Injector Spacer: TBI Spacer #630-105 http://www.turbocity.com/TBIPowerMain.htm $19.95

Make your own spacers

AFPR: Adjustable Fuel Pressure Regulator 9-13psi #630-130 http://www.turbocity.com/TBIPowerMain.htm $69.95

this mod is a pain i havent done it yet
if you have time modify ur stock one.

Fan Switch: Hypertech Cool Fan Switch #4026 http://store.summitracing.com/partd...asp?part=10421 $42.95

the fan switch is a good idea

you really need to get a cam tho, the lt1 cam is good if your on a budget.

I would also recommend you get rid of the stock heads, they arent that great.

the whole exhaust system does need to be replaced, the stock manifolds arent to good at all.

dont forget the edelbrock performer tbi intake manifold

Beast5spdGTA

I'd say the 2 most important things are headers/exhaust and gears/posi. I don't think anyone is in the 14s without those mods. Some money savers are:

If you want to burn tires, don't get any suspension mods, suspension usually helps traction and acceleration. (I assume you meant you want to go fast instead of burn tires.)

Air filter $40-60 K&N etc. Open element. (I'd stay with a snorkle setup)

Headers with 3" y-pipe $320 edelbrock, $$cheaper for others.

catco cat should be ~$70 for a universal slip fit 3"

T-stat autozone/advance auto ~$3-5

Cooling fan switch autozone/Advance auto $8-17 (this will be under certain corvette part numbers) I got one for a '91 corvette for $7.50, but I'm not certain if it's the 200* on 185* off yet.

28 spline axles will be stronger than the 26. Get 3.73 gears perfect for the track 1:1 ratio and 3.73s = ~100mph @ 5000 rpm. Gears/posi = ~$500 with install.

If it's auto. get a torque converter, it'll help a lot so I hear, wouldn't know personally though.

Skip on the wires,cap, rotor, and coil unless you are having some problems already, They are a good idea if you have an extra $100 to spend, but you already said you're on a budget and they won't help going fast.

That's about a grand w/o torque converter and should get you to low 15's/high 14's.

burnouts4ever

my motor is screwed, i have some parts for sale that i was gonna put on my car if interested, private message me

camaronewbie

I have a '90 305 TBI LO3 engine - I paid $500 for the car - I'm like you ... not looking for 120+ MPH, just some fun - and I've been reading here for about 6 months and learning as well. I'm also bound by emissions - here's my plan thus far:

Homemade dual snorkel setup - $25 DONE
- felt this mod right off the bat

K&N Filter $40 new

Ultimate TBI mods FREE

Weiand Action Plus #8000 Intake - has EGR $120 new

Headers/3" catback with hi-flow cat/muffler (brand yet undecided) $400-$500 new

Catco Cat $100 new

LT1 Cam $40 used

1.6 Roller-tip Rockers $100 new

Vette Tranny Servo $25 online

Heads - casting #416 from a parts car I bought - ported/polished, 1.94/1.60 valves - I'm doing the porting (it's a learning experience) - these heads are usually gotten used pretty cheap, and they flow well - check Sitting Bull's article - about $250 in machine shop work, $75 for grinder & bits, and my precious time

Rear - Planned on a used 3.42 Posi - came across a complete drum to drum 3.08 posi cheap ($100) with 24mm sway bar, so it will have to do for now (I'm a tighta$$) - installing this weekend

Prothane bushings all around $140 new

Just redid front brakes - everything EXCEPT calipers - $120 new
(what an improvement!)

Wonderbar $50 new

New Panhard Bar $75 new

New Frt Sway Bar $100

Chip Mods $???

This list totals about $1900 give or take before chip mods. I've scavenged some parts online at good deals - hoping to scavenge some more. There's always the unexpected expenses. And I expect to have to do some new ignition stuff, as well maybe more tranny work. But, it all takes time, I'm in no big hurry, and I spend (or save) a little each paycheck, do my own work (what I can), and learn tons along the way. It also gives me something to do, and I have something accomplished in the end that I can say "I did it" - isn't that the point?

If you are a 1989 - you may have 28 spline axles already - have to actually look at axles to tell - I understand they went to 28 spline in mid 89. My '90 has 28 spline, but no posi and 2.73 gears.

PM me - I'll be happy to expand on anything.