Fulingbusen

I'm new to this forum and have done some reading on the subject. I need to change my valve seals on -86 Firebird Trans Am and figured I would do some small upgrades while I'm at it. I have no emission restrictions (we exported the car when we moved to Sweden a couple years ago) so I will remove the cat and EGR. The redline starts at 5.500rpm so I am assuming that I have the HO engine??

I want to keep the TPI system with stock intake. I'm thinking that I should install headers (with o2 sensors), remove the screen on MAF and perhaps do some light matchporting of the intake/runners/plenum.

Should I settle for stock cam? Would 1.6 rockers help performance?
Is there another cam that works well with my mods?
Do I need to replace the entire exhaust or will headers work with stock exhaust?

Any help, tips, pointers are appreciated. I hope you are not bored with these types of questions.

Edwardgp

Welcome to thirdgen.

Abubaca

iTrader: (3)

Welcome to TGO!

...there is TONS of information on TGO. Best bet is to search, read, and then come back and and post specific questions that may not have been answered directly. ....but no harm in asking these questions.

As for where to draw the line, is based on budget, mechanical know-ho, personal preference and performance goals. LOL....so that means I have no idea what to tell you. ...I can tell you that a few people have done quite well pushing the limits of the 305, but most find it's a losing battle. Again, it's really all personal though. Even though the 305 and 350 are similar in power (at peak RPMs anyway) ya gotta remember that a 350 is going to have a LOT more parts available, and is going to respond better to the same modifications.
Search for basic bolt on TPI mods, and free mods. Then, Id do headers and a catback, not just headers, and maybe some porting...(maybe?)....but focus on suspension and maybe a rear gear, depending on what you have now. Also look into a mild torque converter if you have an automatic. You'll get plenty of seat of your pants performance increases from these mods. A nice suspension set up is surprisingly fun to drive!!!!!!! Any motor will get you going 80 mph on the highway, but not slowing down on the offramp is all suspension!!!! LOL

Fulingbusen

I am trying to decide if I should go with std cam with 1.6 rockers or l98 cam. I guess new rockers is a good idea with l98 cam as well to minimize flex?

Hooker headers, modifies ecu (PCM for less?) and exhaust will be used in either case

Suggestions?

luvofjah

iTrader: (2)

My neighbor just got a new aftermarket cam for his 89 TPI 305 and I think they said 25 hp or so... check out www.dynamicefi.com so hou can tune yourself.

Raf

Fulingbusen

I just pulled out the heads and I had 14014416 heads in the engine.

I also have 14101081 heads that I can use, what heads have better flow? 14101081 look like they have larger ports.

Edit: will my intake fit if I switch to 081 heads?

Fulingbusen

I will use the old heads, this way I don't need to buy new cylinder head covers.

What does this circular thing next the mouse do? The connection to the sensor broke off and I am assumig that I need a whole new "vacuum-thing".

What is the purpose of the sensor and "vacuum-thing"? What is it called?

Joe Tag

iTrader: (4)

I was reading, and I'm like....next to the mouse? LOL Then I saw the pic, yup that's a mouse. The round thing (larger one)is your EGR valve. Smaller is the FPR.
Welcome to TGO.


Edit; If mice are a problem there, stuff fabric softener sheets all around the engine bay and interior while its stored. Apparently they just don't like the stuff. You really don't want to try and find a new wiring harness overseas.

Fulingbusen

Thanks for the advice regarding fabric softener. It is a problem every winter but, fortunately, this mouse only took insulation from the hood.

Since I am removing the EGR (new ecu) I expect that I can remove the sensor and /or complete EGR valve? If I remove the EGR valve, can I just block it of?

Fulingbusen

I recieved a first shipment of parts but instead of 1418-16 rockers I recieved 1416-16 roller rockers. Will they work with my setup?

http://m.summitracing.com/parts/cca-1416-16

Fulingbusen

After searching the internet it seems as if it is correct, I had the bolts for the covers on the side so I should have the pre 87 engine. But is it ok to go to roller rockers with stock cam etc?

Fulingbusen

What are the pressure switches on the block doing? Sending signals to what?

8Mike9

oil pressure sending unit.

8Mike9

Pretty sure you need self aligning rockers, those aren't.

Edit:

Which heads are you going to use?
I'm not sure of the 416's, but pretty sure the 081's used self aligning rocker arms.

8Mike9

You can block it off, but why delete the EGR?

There's no gains by removing it.

Fulingbusen

I don't think that the new headers have EGR and since the ecu is being modified it should not be a drawback to get rid of this?

KMdoza7

iTrader: (1)

https://www.thirdgen.org/egrdiagnose

Fulingbusen

With EGR disengaged in the ECU I do not believe that the advanced timing that the EGR-system allows will make it worth-while keeping the system. But thank you for the advice!

Tony89GTA

iTrader: (7)

Those tubes in the exhaust manifolds that you took off are not for egr. You can by block off plates for the egr or I guess make them yourself, either way if you're disabling it in the chip then you don't need it hooked up.

Be careful with the roller rockers and make sure if you need the self aligning ones you have the correct ones.

Fulingbusen

Really? What are they for?

I hope I have the correct rockers, it looks correct since they are for the pre -88 engines

nomind

Tubes are for the air injection pump.

Fulingbusen

Ok, that explains the small pipe to the cat...

Where does the EGR get the exhaust gas from?

MoJoe

iTrader: (5)

EGR is internal. One of the center exhaust ports on the heads also runs to the intake side. This mates to a passage in the intake manifold, leading the the EGR valve itself.

Here is a view of the intake side of a head. The center port is exhaust, not intake. This "crossover" provided heating for a carb (before FI) to aid in gasoline vaporization, and supplies exhaust for EGR.


Corvette heads do not have the crossover port, nor does the intake base.


So, like this Vortec manifold, the EGR was supplied externally via a tube to the passenger side exhaust manifold. The EGR valve sits in the middle. The supply tube connects right by the distributor hole.

Fulingbusen

Great info, so that is the port that I should block off?

MoJoe

iTrader: (5)

Depending on the intake gasket set you get, there may be a really thin "shim" of a plate to block the port at the head/intake interface. I wouldn't count on this to stay sealed forever.

Search for "SBC TPI EGR block off plate" and you'll get a ton of hits. This has the same footprint as the EGR valve, and mounts in its place on the top of the intake manifold.
http://www.ebay.com/itm/CHEVY-TPI-MP...-/251238195491

or this
http://www.summitracing.com/parts/rf...FSJlMgodAmcA5Q

Fulingbusen

Error

Fulingbusen

I've now installed the roller rockers and began to look at the slots. The slots are slotted and look like they will align the pushrods. Is this all I need to look at to determine that my non self aligning rockers are the ones I should use? Std rocker arm to the right