kramer87gta

iTrader: (1)

Hey Guys,

Well its been a while, but i have been reading and reading and gathering alot of good information. But know i want to put my thoughts to use and get suggestions. As some of you may know from previous posts i have an 87 GTA with a 305 TPI, so what im looking for is a good combonation to make this a fun little car basically what i want to do is, exhaust which i ordered flowmaster, port & polish the heads, plus runners, the BBK 58 MM throttle body, possible cam along with a tranny cooler and gears. Now what i am wondering is the car needs a valve job so would it make more sense to port and polish the stock heads while it is that far apart along with the stock runners, or get a set of heads and the SLP runners. If that is the way to go are the vortech heads the best?? can i take it i need a different base plate?? what other heads would you recommend?? as far as exhaust, what headers would you recommend, im looking at the magnaflow highflow cat with possible hooker headers?? it is an automatic so what gear ratio would you recommed if i were to do gears?? 3:73? which would give me great streetablity and etc. I know every body says just get the 350 but im not looking for anything crazy NA 250-300 to the wheels is perfect for me, being its a convertable and cruiser anyway, i have my 03 mustang GT to go super fast.. i guess im putting this out there for you guys to run with to see what YOU would do.. but just remember the only stipulation is that your sticking with the 305 TPI..


Hope to hear from you all and thanks for any advice given!..

pandin

As for the 58 mm get a vacuum gauge when you start getting vacuum readings in the plenum at WOT then get the 58.

kramer87gta

iTrader: (1)

I guess i am a little confused on why i need to get vaccum readings before getting the TB?? is it to big of a TB for the 305??

So i have a couple of more questions, the car needs a valve job, I have a machine shop so i was wondering if it would be better to have them port and polish the heads considering they will have them that far apart?? or if it would be best to just order a new set of heads? What do you all think about porting the stock TPI runners compared to buying the SLP runners?

Also i want to change all of the exhaust piping to 3 inch, are the custom intermideate pipes from say summit the type of piping I want?? if i were to order a catalytic converter for it, what do you guys recommend i was looking at something high flowing, and it looks like dynomax makes a decent one??

Again sorry so lengthy I guess i just have a lot of questions i couldnt find the types of answers im looking for.

Thanks again to everyone for advice and help.

pandin

The reason for the vacuum test is this, if there is no vacuum drawn, then the bigger holes will not likely make a big difference.

Carbs are cfm rated at 1.5" for 4B and 3" for 2B.

Stock 85-87 Firebird TPI airbox mid piece -- 499.3 cfm
Stock 88-92 Firebird TPI intake bellows w/ integral 90 degree bend -- 693.0 cfm

Stock MAF .................................529 CFM
Screens out................................711 CFM

Stock throttle body......................668 CFM

Stock throttle body w/TPIS airfoil...709 CFM
equivalent to a carb rated at.........787cfm

305 @ 80% VE 6000 rpm...............450 cfm
305 @ 100% VE 6000 rpm.............530 cfm
305 @ 100% VE 7000 rpm.............618 cfm

Codename 47

iTrader: (4)

I'd wait till you get a 350+ cubic inch motor in the car before you spend money on a different set of heads. Same in regards to the cam. Headers and a catback are a good place to start. Personally, if you do plan on going with a larger motor, get long tubes now.

kramer87gta

iTrader: (1)

Ok which makes sense, so if the vaccum is not around those numbers then the bigger throttle body wont make that much of a differnce.

As far as the head swap this is what i was looking at

http://www.sdparts.com/product/SD806...RPMAirGap.aspx

With the lt4 hot cam if that is possible, now if its not what would you recommend?? basically these are the plans i have for the car, SLP runners, the vortec head swap, BBK 58 MM TB, Full exhaust changing to 3 inch piping instead of stock 2 1/4

With this basic set up is there a tune i will need to have done, or can i just call say superchips tell them what i have done and have them burn me one?

kramer87gta

iTrader: (1)

Also with the head kit above, is this a plug and play deal? as in put all parts on and drive away, or is there going to be some dyno tuning involved?? Also what would this combonation change for my exhaust options as far as header size and such i know the collection size wont matter all that much.

pandin

Superchips will be money lost. They are just a little more fuel and spark Adv.

The farther you get from a stock set up, the more important retuning/recalibrating the chip becomes. If your new chip programmer does not ask, about a data log (from your car) and at least as many questions as say, comp does when sizing a cam (check out their on-line ordering list), then I would move on to someone else (free re-tunes and short turn around times are a plus).

Dyno tuning WOT is easy compared to DD, cruising, stalls, bogs, stumbles, and a host of other annoyances.

GTA Sammy

iTrader: (1)

ThirdGen.org is probably the best place to get opinions/ advice. I've been asking here for years...... I can't afford to do things more than once soooo
Here's my

If your gonna keep it a 305 what do you want torque..... or HP?

Torque is what you feel in the seat of the pants and spins/chirps tires from now till kingdom come....... Horsepower is that never ending pull that you very rarely use..... You usually can't have both.

If you go with Vortech heads you'll have to change your intake to a Vortech style manifold so you'll be paying more than you have to: Heads and Intake/Runners + Cam + Hedders + Catback system + on and on and on

Why don't you;
1) Keep the stock throttle body & runners cause they'll flow enough anyways ( they are the same as the stock 350's) open them up alittle if you want to (it's not hard)
2) Get yourself a high lift cam (add 1.6 Roller rockers if you want to) with a reasonable duration to enhance low and midrange torque where your engine will be operating most of the time
3) Find good flowing heads (OE or Aftermarket) with reasonable intake ports & small combustion chambers 58cc's or shave them smaller to raise compression ratio (Hell, I was gonna run 58cc S/R torquer heads with Felpro 1094 Head Gaskets 0.015" compressed) on my 350 GTA to do just that......make more torque!!!!
4) You can use 1 5/8" headers, but you may want to go with 1 1/2" with the 305..... do some research, but I would stick with the shortie style hedders because your tranny crossmember will cause you problems as far as fitting the longtubes in. Believe me I've already been down that road..... Try Hedman Pn 68481 they're 1 5/8" with air tubes and y pipe if you need to keep it smog testable.
5) You won't need to change your gearing with all the torque your gonna make so save your money.... throw a shift kit in for fun.... they're not much $$$$
6) Don't worry about tuning unless you go with some crazy duration cam. With reasonable part choices you shouldn't have to make prom changes.

Well like I said that my 2 cents...... you said it was gonna be a convertable cruiser anyway, by the way when did 1987 covertable GTA's become available????

pandin

It is funny to me to listen to the Torque vs HP chat. The real difference is lower RPM HP/torque vs higher RPM HP/torque.

400 ft/lb at the wheels, is the same as, 400 ft/lb at the wheels. It does not matter if the engine is running at 6000 rpm in first or 4000 rpm in 2nd or 2000 rpm in 3rd.

All... repeat ALL.... HP is a function of torque. Torque times rpm = HP.

There is absolutely ZERO HP without TORQUE, and ZERO TORQUE without HP. ZERO (torque) times anything (rpm) = ZERO (hp) and ZERO (hp) divided by anything (rpm) = ZERO (torque).

HP = Tq x rpm or HP/rpm = Tq

This is the heavy head short handle hammer vs the lighter head longer handle hammer. One person says I have a handle hammer and it is better than the head hammer.

If you care to check it out, ALL hammers have heads and handles. (all engines make torque and rpm which = hp).

I guess people just like to argue.

Codename 47

iTrader: (4)

Do you plan on swapping the motor out in the near future (next couple of years)?

kramer87gta

iTrader: (1)

Hey Guys,

Thanks for the responses!.. well i guess i really dont want to do anything radical with the car, my main goal was a good mix of both HP and TQ without changing the motor, Im still finding more and more information about the car as i know its rare but still dont know how rare. Also as stated it is just a summer cruiser my eventual goal is to finish restoring it and really enjoy it with out getting to radical, i have my mustang for that. So i was looking for suggestions to get around 250 plus HP. That is why i was thinking of the Vortech head swap like the link I gave above, then adding the SLP runners or porting out the stock ones, bigger throttlebody and CAI, headers, new high flow cat and finishing off the exhaust which i have allready purchased.

I still plan on keeping the 305 no motor changes any time soon, i might look for a t-top 350 and have some fun with that as well.


So some questions to GTA Sammy:

1. Im sure if i looked hard enough I could find it, do you have any information for porting, i have never done it but im assuming you just use a dremel tool and go to town. So is there really not a big difference between the stock runners and the SLP runners??

2. What would you recommed for an all around cam for the 305?? LT4 hot cam?? does comp have anything worth looking at?? I dont want a lope that makes the car sound like is not running but a nice tone to tell its updated would be nice.

3. What are the advantages of the vortec setup as in the link above?

4. So this may sound like a dumb question, when looking for header sizes what am I actually looking for??

5. If i were do tuning were would be a place to get a EPROM burnt as a plug n play kinda deal?? or would taking it to a dyno tune help??

Codename 47

iTrader: (4)

I'm really not sure how a 350 vortec head will work out on a 305. I don't know if people have done it or not.

As for headers, buy a set of shortys. 1 - 5/8" primaries will work good. If you were planning on going with a bigger cube motor or really putting out some power, I would suggest long tubes. I would recommend (along with many others on this site) to get the Hooker pn 2055. They are arguably the best shorty headers for our cars. They also include the y pipe.

You definitely want to do a complete exhaust swap on your car. The factory exhaust is extremely restrictive.

Hope that helps.

GTA Sammy

iTrader: (1)

Wow.....
I thought that everybody knew what I was talking about with my post...

I guess I'll have to be a liitle more specific with the responses that I make to someone looking for help.

I think that what Krammer was looking for was a real fun daily driver. Not something that needed 7000 RPM of screaming 305 Miniram.... to make fun HP/Tq

Krammer, think of what RPM you'll be using this car in and go from there!!!

Your stock '87 305 has a 202/207 duration and .404/.415" lift
the LT4 cam has a 218/228 duration (too much for your 305) with .492/.492" lift
Crane Cams has a 206/214 which is more computer friendly with .497/.497"lift ---- .530/.530" lift with 1.6 Rockers

Just do your homework

pandin

One of the hardest parts, of getting "Advice" on this board is.

Question, what do I need to do, to build "MY Perfect Car" (the Original Poster)?

Answer, YOU need to build "MY Perfect Car" (a bunch of the answers).

The DD sometimes get the dragster answers, and "Bigger is always Better".

Terms that have different meanings to different people.

Fast
Quick
Slow
Streetable
Peanut
Big
Small
Lots
Little
Hugh
Radical
High
Low
Bad
Monster

and many more......."Everything is compared to what, stock?"

More HP is more money, new parts and old broken parts, the more of the new "HP" parts you add, the more of the other you get, which leads to more new parts. This is under the direct control of the right foot.

kramer87gta

iTrader: (1)

"I think that what Krammer was looking for was a real fun daily driver. Not something that needed 7000 RPM of screaming 305 Miniram.... to make fun HP/Tq"

That is exactly what im looking for "suggestions" for, I was looking at a start direction then taking it from there, i know i have some things to read and figure out, i have been learning from alot of people in a short period of time, and that is awesome, so i was more or less looking for feedback as im learning in combo's i may point out or pro's and con's for certian ideas to get the whole spectrum.

Thanks again guys!..