exhaust mods and gains???

[bro_d_83]

My car is an 87 GN and I am planning on purchasing a bunch of exhaust mods from Poston Buick. The items I am getting are the headers, 3" downpipe, crossover pipe, and the Hooker cat-back exhaust....and if it helps, gutting my cat. I am just wondering how this will sound and perform. How much HP can I expect? The car is not modded very much....just a LT1 MAF w/Translator and a mandrel-bent turbo intake pipe w/ 9" K&N. I hope someone can help me....and if they have an easier way to get more horsepower for around $1100, please tell me what I need and how much it will cost me. Thanks!

Brodie

 

[Slow91z]

These cars do not need headers until you are going at LEAST 10's and then I wouldn't buy postons.

Get a dump tube to replace the cat, then at the track you can opening the dump pipe, and you don't need expensive exhaust. Say $45 just for grins

Get a new fuel pump, and hotwire kit...to support the mods you are going to do later. Like $125 or so

Get a scantool. Say $250

Get 2 good chips, 1 for the street, 1 for the racetrack. Depends on what you get.

Get a Boost gauge. Dunno.

Put good fuel in it. Depends on the fuel.

Crank the boost up to about 20 PSI. Adj. actuators are like $80 I THINK, so not sure got mine for free :-p

Have fun.

Depending on how much you go to the track, and how fast you want to go on the street, this list can be changed to meet your needs....Give us some more info on what you are trying to do and I/We can be more precise.

For fun on the street you need a jug of race fuel at home or Alcohol injection.

 

[brittken]

Mods for $1100.00

Adjustable fuel pressure regulator. $100.00
Walbro fuel pump. $100.00
Performance Chip
$75.00
Exhaust of your choice $?$
Rear spring Air bags $60.00
Hotwire kit $75.00
3" down pipe $200.00
Higher rated injectors $250.00
Adjustable wastegate $100.00

I would go with these type of mods first. The exhaust will help some but these seem to be the 1st mods that will make a major difference in the way your car performs.

 

[bro_d_83]

Well, I'd like to get into the mid-12's or quicker, but I don't wanna loose fuel mileage (I drive the car a lot) and I don't really wanna spend more than $1000 on it. I just want to lightly mod it for now and progress more when I get more time and money. I do like the idea of a boost controller, but what would I need to run high-boost? I'd also like to get a good chip, but don't know what kind to get....

 

[Oaktown]

i have the exact same set up as you were thinking of getting. it came on my car when i bought it and i have to say i would not reccomend that stuff until you mod it more...keep the stock headers they are good, postons suck...if yours are cracked just get em repaired. i dont know how much a difference the dp makes, i have it and my car is still kinda slow compaired to the other turbo buicks i had in the past. i like them stock. get a scan tool, boost gauge, chip...if ur gonna get injectors make sure you match it up with ur chip, and they say get the walbro 340 fuel pump and booster kit if u do the injectors...i havent put mine in yet so i cant tell you how it is...

 

[DJay]

I'd start researching a little on Alky and what your options are ... talk to RedRegal or Razor about making a kit yourself or check out SMC.

Once you get your fuel system up n runnin with a hotwire, pump and ajfpr thats the next thing i would reccomend along with a decent chip (Joe Lubrant can set u up with a nice one). Turned my car into a MONSTER! Cheap too!

Good luck, have fun....

 

[MARINES185]

I have exactly the same stuff you mentioned on my car.
bought it all from postons. the headers aren't really headers.
they're more like custom manifolds. they are a nice piece
but they need to be ported. you will see the mega amount
of weld they used to weld the flange and tubes together.
just get a die grinder and clean it up a bit on the inside.
as far as improvement, i can't say cause i never ran the car stock.
it did run 13.28 with those mods,93 chip,2800 stall converter,
and 235/60/15 bfg drag radials.

 

[Quick6'n'-K.C.]

SUMMIT sells that hooker cat back with the 2 1/2 inch downpipe for 280.00 shipped this is the part number for that kit with the quiet aerochamber mufflers
PART NUMBER HK-16810

purchase a THDP with test pipe, make sure you get the stainless steel one, the mild steel ones will rust- price is about 439.00 or very close to that-

here you go, here is a link to the downpipe at this site, MIKE LICHT is a great guy to do business with

http://www.fullthrottlespeed.com/Dynamic/items.asp?CartId=953-EVEREST-8313OURUY146&Cc=BUDWN&tpc=

here is the fuel pump-

http://www.fullthrottlespeed.com/Dynamic/items.asp?CartId=953-EVEREST-8313OURUY146&Cc=BUFP&tpc=


you can leave the car bone stock, and these mods will give you at least 45 horsepower over the stock exhaust system with the cat into place-


and buy a chip from eric marshall-

his site is in my sig-

HTH
BW

 

[wh1-Denver]

I would get an alky kit ($150 DYI, $480 Razor's Progressive kit ( great Kit I have one and love it, 26 psi on pump gas and no knock!!)), get a scan tool direct scan or scan master($299new or buy used ), a test pipe to replace the cat($50-80) look on ebay or hear, the hooker exh with the aero chamber muflers $299?, and an adj waste gaste actuator ($30used-$80new).
Get teh scan tool hooked up and read alot on how to tune the car, make sure it is running right. Then put the parts and start crankning the boost up and adjust the alky to keep knock down and keep raising the boost until you can't keep the knock out and then back the boost down 2psi. Allways make sure that you have alky at the higher boost levels. I do not recommend the SMC kit they seem to be having problems with the pumps failing from corrosion. That is very bad when you are running high boost levels.

The best way to get these cars to run fast is opening up the exhaust and intake, get it dialed in right, and alky to crank the boost up.

Have fun and make sure it is tuned right.

 

[GNSCOTT]

Cut and past the link to my web page before you do anything.

Just re read some of the posts. Why would anyone reccomend and alky kit to a newbee??? Don't ya think maybe he should learn how to tune a car before you reccomend it??

 

[DJay]

alky didnt seem too difficult for a newbie like me ... although i havent had any track time to see how outta tune my car is yet. waitin on $$$ for the new trans b4 its track time.

 

[kevans]

Start Here.

Read EVERYTHING you can before buying anything. There are a TON of things out there that work and some that don't. There are known combos to get you where you want to go just read before you leap. There is a TON of information on here and gnttype.org but be willing to spend a good week reading everything you can.

Believe it or not, it is possible to slow down these cars if you don't know what you're doing.

Kev