What could be done on these engines?
safe mods. Something I can work with..
I would like to beef it up a bit, im already impressed with performance but a bit more when I need it wouldent hurt.

Full blown tuneup would be you first option. Then after that work on the intake and exhaust.

So far I have done the following mods to my 1989 Buick Lesabre Limited, which is mechanically identical to your Bonneville, except for the tranny gearing I bet (I have the highay gearing so I can hardly even spin the tires on gravel, but from 30-70 mph the car is actually not too bad.

Mods:

CAI with K&N 9" cone filter
1999 type II Delco L67 ICM/coil packs
Belden Max blue 8MM wires (from NAPA)
removed MAF screen from TB
140 amp alternator
California Customs breather to replace oil filler cap since the LN3 engine'* don't have a PCV valve to release excess crankcase pressure.
STB
FE2 rear stablizer/ant-sway bar
Polyurethane end-links for the FE2 bar
16" Buick rims (from a 1993 Park Avenue) with 215/60/16 tires.

These are the only performance (power and handling) mods I have done so far. I am going to be putting a full 2.5" exhaust from my 1997 Bonneville SSE parts car since it'* a free mod and it should net me around 5-7 HP ....maybe as much as 10-12.
I will also be putting a 180* t-stat in soon as well as switching from the Autolite 605'* to NGK TR-55'*. A tranny cooler is also on the to do list.
With my current mods I must confess the car is alot stronger, but it also could be the tuneup that has been given to the car as I just started driving it about 3-4 weeks ago and it had not been run in almost 3 years.

That'* interesting blueeyes.. FE2, what'* up with that? Do you have F41? If so, are those better than the F41 equipment?

The LN3s have a PCV Valve. I know mine does, because I had the hardest time getting the sucker out.

Also, won't the 2.5" exhaust be too large? Or can our cars benefit from that? Would it just bolt up to the stock headers? Sorry to get off topic here.

The Delco ignition did wonders for my engine, even with the old plugs and wires. Aftermarket coils, or coils from a 97+ */C engine will net you a few extra ponies also.

Don't forget about the 180* thermostat before anything. Before you do any single thing on that car, do that tstat. Also, do it before [not during] the time you mod, because there is a good likelihood you will have a leak [I know I did].


-justin

The Lesabre had FE1 stock -and that 1987-1991 FE1 rear sway bar is literally half the size of the 1997 FE2 bar. It helps, but I have to figure out my front end steering problem, which has become noisy, and almost lethal on hard accelleration above 50 mph (can you say torque steer that is back and forth like a monkey with rabies bouncing off walls 2 feet apart?)
The 2.5" will definitely benefit the LN3. Merlin 91/97 I believe has a full 2.5" exhaust on his 1991 SSE. That 2.25" exhaust piping is too small.
I also know that if someone can get an adapter plate made up a L27 TB would do wonders attached to a bored out LN3 UIM (or better with a L27 upper end). That LN3 TB is literally about half the size of a Series II L67 TB. :(

Also, where is the PCV valve located? I looked and looked but can't see any, and didn't see anything in the owners manual when looking at the specifications pages.

PCV is buried under wiring harnesses and rear bank spark plug cables almost directly behind the power steering pump. Be careful, the rubber grommets gets hard and brittle and are easy to break. The limiting factor in the exhaust system will be the cat., where the stock one only flows 223 cfm @ 1.5" of mercury. The 2.25" pipe is actually large enough for the flow needed, if it were straight, about double what the stock cat. can flow, and of course the stock muffler will add to the restriction. The 2.5" size is probably about perfect considering the bends, but the cat. flow needs to be a lot higher and a good free flow muffler to complete a good system. Anything will likely help some. The stock MAF and throttle body are an almost perfect match to each other. The flow rate only changes 3-5 cfm if the parts are tested individually or as a set. The larger throttle body will help some, particularly at small throttle openings where the greater area allows more flow more quickly. Maximum flow will likely not change, but the MAF can flow more air than needed for an N/A engine, up to about 200 hp or so.