91 A4 coupe, FX3 and G92. 110,000 miles. No engine or drive train mods yet.
What else should I replace while the intake manifold is off? So far I am installing Bosch III injectors, EGR valve, ported stock base, SLP runners, aftermarket valve covers, tach filter. I have been told by others that have been there to install a new fuel pressure regulator and oil pressure sensor. I will be porting my plenum to match the SLP runners and have already cleaned out the throttle body and related attachments. Cooling system has been flushed and has fresh coolant. Thinking I should go with a new GM thermostat too.
I am also in the process of doing the exhaust with catless front Y pipe, high flow cat, "Performance" mufflers from Corvette Central. I am having a cross pipe welded into the rear Y as the pipe is in good shape. I have done the same exhaust mods on a previously owned 87 and was real pleased with the sound and modest seat of the pants power boost.
She is not a drag racer, just a cruiser. When I bought the car I was planning on doing enough mods so that I could keep up with the C5s that hang out with my West Michigan Crew. But now a couple of folks in the group have bought C5 Z06s along with one person who bought a new Grand Sport and another completely crazed individual who just took delivery of a red 2010 ZR1 ! No chance of keeping up with that bunch now!

 

Reading your list I can't find anything you have missed except maybe replace the fuel rail cross over 0 rings while your in there.......Good Luck...WW


PS..Pete K , the guy that just posted below can build you an engine that will keep up with your friends....Trust Me.....Well, maybe not the ZR1..WW

 

If you are ambitious, maybe a set of fresh valve seals? Is your car doing the typical chevy blue smoke start up puff?

 

If you can legally, get rid of the air pump setup. You might be able to see the engine after that stuff is removed.

 

1,5 rr's while the valve covers are off.

I meant 1.6

 

Good idea!

 

I meant 1.6

 

I would but I am afraid of the global warming ***** and what they will do to our hobby in the future. My area of Michigan does not have smog tests right now but it has been proposed in the past.

 

No smokin yet! I will probably leave that for a winter project though.

 

O rings? I will do that - thanks!
The ZR1 guy just notched up the "keep up with the Jones" competition by a huge factor. God bless him anyway. His girlfriend is the one that drives the new red Grand Sport vert too. I hate them both!!!!!!

 

If you've got the intake out, time for a new camshaft.

 

 

I hate them too and I don't even know them....WW

 

If you're good at porting, I'd mega-port those SLP runners like I did. If not, send them to Mike @ CorvettePlenum.

The cast diameter of the SLPs isn't very impressive IMO. You only gain .05"-.1" over stock. With porting, the size can be greatly improved. If you don't want to do that, I'd recommend TPIS/AS&M runners vs the SLPs. Their diameter is closer to .2" over stock.

Trap times of those who've compared support the difference. Only if you port the crap out of the SLPs can they be made as good as or better than other LT runners.

I agree the valve seal suggestion and would up that to new springs while you're at it. They're going on 20yrs old don't you know!

 

Geez if you have all that stuff off of it, do the valve seals!!! it will take you about 2 hours with a hand winder, and maybe 30 minutes with a breakover valve spring compressor.
Be sure NOONE walks around the garage with the air hose attached. I had someone kick the hose and it popped off the compressor. just lucky I was taking the spring compressor off after doing that seal.

 

although I suspect it's implied, when you're porting your plenum, remove that EGR plenum ridge behind the throttle body face, and maybe remove that bevel on those two plenum TB ports and make them straight.

grind a little on the side walls at the front of the plenum inlet just to straighten out the flow at WOT.

it almost goes without saying...

 

May as well service the heads and throw some new rings in.

 

May as well siamese the intake base while you have the grinder out

http://www.thirdgen.org/siameseport