I am new to this list but Ive had my 1994 Z28 A4 for a while now. It has 83k on it.
Mods:
Built 4L60E w/2500 stall (up to 650 hp capable)
magnaflow muffler w/ bolt in cat & test pipe
160 t-stat; ud pulleys;
K&N cold air with vortech elbow
MSD wires
LT1 edit (minimal tuning)
(removed) NOS wet fogger kit-75hp shot( I want my motor to last! )
subframe connectors; 2.73's out back
My question: I am looking into installing some 1.6 roller rockers but am not sure if my valve springs are strong enough or should/need to be upgraded? Does the 83k on them affect much? Any performance gains?

 

Save for LT Headers and Exhaust then get a mail order tune from madz28.com. Then do your 1.6rr's and if you want to stick with the stock cam I would suggest getting LT4 springs as some insurance, but some guys run stock springs.

 

I read one time that stock springs only give you like 1/32 of an inch of leeway so I would go ahead and replace your stock springs with LT4 ones since their not that expensive.

There are a lot of good discussions if you search under "roller rockers"

 

1.6 rockers (full roller, crane gold) can be had for $100 themselves, springs another $120, pushrods another $40, guideplates another $20...

~$280 if you do the installation yourself ...

IMO I'd just get a good and inexpensive set of headers if you haven't already and do rockers at the same time... if you have friend(s) that can help you, that will only be to your benefit as rockers + valvesprings are difficult... but headers are even MORE difficult and even MORE time consuming and could have far more implications (exhaust leak(s), rattling etc.)

oh yea btw, if your exhaust is so loud that it rattles your car, chances are if you've been driving around like that for a long period of time, bolts have started to rattle loose...


just FYI....

edit: and oh yea, when i got the 1.6 rr's put in on my car, 3rd gear opened WAY up.... it was like night and day!

 

My experience with many LT1's work like this.

If you have bone stock valve springs. Replacing them with better ones is always an advantage. Nothing too crazy but enough were valve float cannot be an issue. Even when going up to 1.6 roller rockers on stock springs come close to coil bind.

To replace the springs, getting a compression tool from crane that uses the stud hole to compress both the springs for easy to removal. You just need to keep the valves up as with any spring swap.

I dont care for LT4 springs, but if you dont plan on a major cam swap anytime soon, then you should be fine.

Removing your manifolds will pretty much be needed, and then you might as well put headers on the car.

 

I have heard that the Pacesetter LT's are junk. I know that LT's in general have much better gains in the long run, but for my needs, the BBK shorties are adequate. Plug access is always a concern, especially the one on the passenger side at the far back and the one right below alternator.
So, when doing the valve springs, do it when exhaust manifolds are off for Easiest access?
By the way, how hard is it to install aftermarket headers like BBK shorties? Keep in mind I have an Automatic.
From what I read in the posts, 1.6's (upgrade the springs for security) with headers can make considerable gains? I guess the ability for the motor to breath out better without being choked helps.
Daniel
1994 Z28 A4
14.3's @ 98.7

 

Where in the heck are u finding Crane 1.6 rr's for $100???

 

got them for 100.00 from a friend of mine if you find them in the right place they can be a great deal, but they are 3/8 inch.

 

Ditch the 2.73 gears. I would do gears and headers before the 1.6 rollers

 

agreed with above, 2.73 gears blow... get a 3.73 or something....

and headers... just make sure you do it right THE FIRST TIME.... saves a lot of pain


after all that + 1.6 roller rockers, you'll be looking at 300+rwhp with other accompanying bolt-ons....

 

I don't know where you are getting your information, but I..like most others, think that the Pacesetter Lt's are a great bang for your buck. Shorty headers are junk, and have bad plug access. LT's, 1.6 RR's, and a tune should gain you a good amount. Do you have any plans to swap the cam in the future as well?

 

I have no immediate plans for a cam of any type. I want to keep the car engine stock for reliability and to keep it going throughout school.
Pacesetters are a good price but they are not emissions legal and CA is super strict. BBk's will allow me to breath easier without giving up emissions.
I made 255hp to the wheel at 5200 rpm & 325 torq at 2200 rpm back when I had the HPP programmer. With LT1 edit now, I have not done much tuning. I have got a deal on dyno tuning for a great cost which I will do in the near future.
Since my ignition is failing (damn MSD wires), Im upgrading to an MSD blaster coil, factory plug wires, 3.73's, headers. (& 1.6rr).
By the way, does anyone advise on a used posi unit so that I can put in 3.73's? Its either that or a spacer for the gears. Since I have 2.73's, the dilemma of the smaller posi units has got me going in circles.
So you people claim w/ headers, gears(no hp), and 1.6rr's, 300rwhp is practical-with other mods mentioned earlier?
Daniel
94 Z28 built A4, 14.3 @ 98.7mph (all day) N/A
12.7 @ 107 on 75 wet shot.

 

There is no need to get another posi unit just because your car came equipped with 2.73's. You can get a Ring and Pinion gear set that is thicker for the 2 series carrier, and then there is no need for the spacer either. I have heard that those BBK's are pretty ****ty, same for Edelbrock ones. Look into Mac mid lengths....they may be more your style. I am not so sure you will hit 300RWHP with that setup with an A4....with an M6 you would be there tho.

 

Yea, with the A4, hp is robbed more, but the hp is consistently put thru the drivetrain. Anyway, The good thing about the spacer is with the larger ring and pinion is that if my posi goes out, the spacer can be removed and the larger new carrier be installed; if I use thicker gears, how am I going to eventually upgrade the carrier. So many dilemma's.
Then it comes to the point that a whole rearend from another car is cheaper than buying and installing components separately...from a junkyard that specializes in F-bodies. A whole rear end costs about $300 out the door with at least 3.42's which a kick in the *** compared to 2.73's and has the better carrier. Otherwise, Im looking at $400 at least, $200 just being professional install!!
Rear ends just bolt in.
Im going to look into the MAC mid lengths. I had a friend who had the Pacesetter LT's and said they leaked and were junk-dont buy 'em he told me. So BBK's seem like a good bang for their buck, i really like their price.
Daniel

 

Upgrade your carrier how? Most of us will agree that the stock rear isn't worth putting that kind of money in. "Upgraded" carriers, along with gears will end up costing alot of money. Chances are you will break the rear anyways. There is nothing wrong with the factory carrier you have as long as it works well. You may have a lot of dilemas in this area....
Pacesetter LT's are of great quality and are a very nice. They provide very good gains. Any header can be classified as junk because they leak if not properly tightened, or improperly installed. Do some searches on here, and you should be able to find a ton of info on headers...this may change your mind as far as your choice.