Hello all, I am new to the ls400 crowd, I just bought a 1992 LS400 with about 208k on it, the water pump was completely seized. So I replaced the water pump, timing belt/pulleys, and thermostat and it runs like a champ!



Also in that picture you can see my dyno with my RB20det swapped e30 on it, I own and operate a shop named CS Motorsport in Montana and have been wanting an ls400 for a while to become my new daily.

So far my plan is:

1. run it and get a base line number.

2. Do a large tune up, that so far plan is to do
-spark plugs, plug wires, caps, rotors
-Valve cover gaskets, oil pan gasket, oil change
-transmission filter and fluid change
-fuel filter
-air filter
and anything else that I find needing attention and then run it on the dyno again

3. Do the airbox mod that seems to be really popular, run it, then likely build a section from the throttle body to the maf

4. Remove rear cat, maybe rear muffler delete? egr delete? not sure yet


So does this sound like something that you would want to see? is there anything else that you guys would like to see me try?

 

I'd really like to see how much extra HP can be had from the factory stock condition. That car looks nice. Is it gray? What options does it have? Please take care of the sheet metal and paint. Power train mods okay bending any metal any place or holes etc. on the unibody not good.

 

noiceeeeee.... happy to see an LS in good hands.

the airbox mod i'm pretty sure doesn't directly add any power but it does add noise and louder means faster so i guess indirectly it adds power lol... i'd also check the throttle body itself to make sure it's not all caked in dirt.

 

It is a dark green, I haven't had a chance to give it a good wash/claybar/wax. It seems to have most of them, traction control, sunroof, I am not really sure what came standard since I know they came pretty well equipped.

 

Well I will get a real world results to see if it does add anything. Good idea, I was even considering pulling the upper intake to clean it all out and ditch egr.

 

Most of the time with the gold option it does have most options.
Here is a quick list of options and maybe not complete.
Traction control
Leather seats
Moon roof
Driver memory
Heated seats
CD player in trunk
Phone (dealer install)
Air suspension
Rear sunshade
Power steering wheel extend
Power head rest front seats
Power seat belt adjust on B pillar
Fog lights
===========
Moon roof is so prevalent that its almost a non option, very rare not to have it.
==============
Things that are not an option
Automatic transmission
Power windows
Air conditioning
Power seats
Power outside mirror adjust
Cruise control
Power door locks
Security system
Inside trunk release
Climate control
Valet Lock and key
Took kit and Medical emergency kit

 

You'll probably see almost zero gains.

 

Yeah just fix it clean it and drive it, don't mess it up.

 

Cool.
Don't be so worried.

it has these I know, I will have to check to see if it has a few of the other ones.
Traction control
Leather seats
Moon roof
Driver memory
Heated seats
CD player in trunk

 

If you modify the air box be sure to dyno before you do it. Because airbox mods (aside from a K&N drop-in filter upgrade) on most cars at least, provide gains primarily in the noise department. Would be cool to see actual data.

 

That is the plan.
1. as is dyno
2. larger tune up dyno
3. air box mod dyno

 

welcome and i'm very curious to see any gains from opening up the exhaust (i.e. removing the resonators and mufflers). FYI the car's cats are high flow from the factory.

in general the car is tuned to the standard equipment and is sensitive to changes such as the EGR and intake mods as you plan on doing. even running cat-less the car will not perform optimally. i'm not talking about huge changes like the car would go into limp mode, but i would simply like to make you aware that a mod usually associated with gains could actually result in the opposite with this car.

regardless i'm looking forward to your numbers and progress!

 

with all the stuff you mentioned

I'd guess 160-180whp.
tops.

 

Well my car being a '92 doesn't have any 02 sensors after the second cat so getting rid of that one shouldn't affect how it runs, I think I would just plan to build a new section from the cats-> Y pipe -> rest of the exhaust to get smoother flow and no cat there.

Well that is why I plan on testing this stuff on the Dyno, to see what it actually does for the car. I don't really care if it really gives me gains, I just care about finding out some results that are backed up by my dyno.

 

Wow, welcome!

I'll be keeping an eye on this thread. I am really interested to see how the LS performs stock, after all of these years.