500E/E500 performance from a 400E/E420

[400Eric]

You all know of my 400E's exploits in the drag racing thread, and you have all seen the two videos of it running literally side by side with a modded 500E ALL OF THE WAY DOWN THE TRACK! It is in fact the quickest naturally aspirated stock 2.24 geared 4.2 powered W124 in the universe!

Now we are talking about 500E/E500 acceleration performance here, not handling performance. That is a separate topic that I will let someone else start a thread on.

I'm posting this thread to THIS SITE in the hopes that we can get some of the performance oriented 034 owners back here where they belong. (MOST of the 036 guys DON'T REALLY want you.)

Edit: I forgot to mention that if you follow my recipe, you will not see any loss of your existing fuel economy. I've been very careful to preserve fuel economy with this car, as it was my family's MAIN car. There are folks who think lower rear gears are a good idea but that's a very "involved" mod that will also cost you fuel economy. Plus, you very well might end up with a car that now doesnt hook very well. That 500E that I'm running side by side with in those videos is in better shape than my 400E, has lower gears AND a bigger engine, gets 3 MPG less fuel economy, and yet I still run side by side with it all the way down the track. Still think you need lower gears?

First of all, start with a 93-95 034. The 92s have a full one point lower compression ratio, and as a result, don't make as much power. Plus, there are some other more minor internal differences as well that, when taken as a whole, rob a little more power on top of what the lower compression ratio robs. (maybe GSXR will chime in here with a link to his site where you can read more about said internal differences).

Before you do ANYTHING, you must make sure your spark plugs, spark plug wires, caps, rotors, etc. are in great condition. If they aren't stop here now and fix this stuff. If the spark plug wires have a white looking powder on them, THEY MUST BE REPLACED! If they've never been replaced and your car has over 100,000 miles on it, THEY MUST BE REPLACED. Lot's of folks say I'm wrong on this. NONE of them have a stock geared 034 that runs 14.200 in the quarter.

Make sure your air filters are clean too. Don't bother with K&N crap. They don't filter very well, and you won't see a performance gain either. I once did back to back track testing with no air filters at all. Guess what? No difference! None! Now if removing the filters didn't gain me anything, how much will K&Ns gain you?

Warning: I absolutely refuse to get into any arguments about what I have or haven't done. Good or bad, it is what it is. I am simply sharing my secrets, spilling the beans on what I have done to get where I am. I'm just trying to give back! You all can do what you want and prove me wrong with quicker timeslips!

OK, this is how I did it. I am going to divide this up into three parts: One for the mods that you MUST DO, one for the mods that you should do, and one for the mods that I'm GOING to do to go even quicker.

MUST DO MODS:

GET 92 ECU AND INSTALL IT! Don't even bother trying to do anything else if you aren't willing to do this one. For the record, I am THE FIRST PERSON to propose that this was a viable idea for 4.2 M119s. Before I came along, it was believed that only 5.0 M119s and M120s benefitted from a 92 ECU swap. This is a documented solid 2 to 2 1/2 tenth reduction in E/T right here. It's because 92 was the last year for WOT fuel enrichment.

Dump the stock resonator and muffler. I put a nice "Y" after the stock cats and ran straight 3" pipe all the rest of the way to the back of the car.

Remove the panels/wipers/motors from below the headlights. This is a very high pressure area that, once opened up, rams cool dense air directly into the air collection buckets that are located directly behind the headlights.

Do the Jim F resistor mod. These cars MUST be kept cool! They run faster when they are cooler and everything under the hood will last longer as well.

When at the track, run the car as stone cold as possible!

SHOULD DO MODS:

"T" bar mod to the trans. I went three full turns.

As your fan clutch ages and gets looser, DON'T replace it. With the Jim F resistor mod, you can let the electric fans pick up the slack.

Light weight rims. I'm running 16" CLKs.

Remove the two screens from the mass air meter. Leave the one at the exit of the air cleaner assembly in place. Some folks will want to give me a lot of flack for this. Please keep it to yourself. Again, I'm just listing what I've done. You all can do what you want and prove me wrong with better timeslips. More power to you!

Use a 92 4.2 EZL. (This last one may only work for 93 cars and may not work on 94-95 cars. I'll update this thread after I've tried it myself on my 95.) This will give you a little more ignition advance. This is worth a little less than a tenth, but every little bit helps. Better be running good gas though!
Edit: This EZL stuff gets real complicated. When the open deck blocks came out in late 93/early 94, the EZLs were changed yet again, because, supposedly, the open deck blocks cool their heads better, making them more tolerant of more ignition advance. So if this is true, there may not be as much gain running a 92 EZL on a car that originally came with a EZL that has a part number starting with a "015" prefix. Again, on my early 93, the 92 EZL was worth a little less than a tenth in the quarter mile. It may not be worth as much on a 94-95 car, if it even works on a 94-95 car! The only way to know for sure is to try it, or wait for me to try it on my 95!

Try to reduce at least a little weight. I removed my front carpets, pads, and insulation. Sometimes I remove the spare, sometimes I leave it in for traction.

I bought an E-bay chip that on the dyno gave me absolutely zero gain, but it did at least allow me to raise my shift points to 6,500 RPM, which helps a little with the huge gap between gears on our old tech 4 spd automatics and our tall gears. I'm not sure if I even recommend this one, but I had it in the ECU when I ran my 14.200, so in the interest of full disclosure I have to list it. If forced to say yes or no I'd say yes, it's a benefit to have it. However small the benefit is, I think there is one. I haven't really been able to document it though. Too many other variables!

GOING TO DO MODS:

The rest of the exhaust system. ALL of it. GSXR has some great info on his site. One of the things I learned there is that the headpipes immediately after the exhaust manifolds are only 50mm in diameter! That's the same size as the headpipes on my little M103s! Not acceptable! I'm going to port the outlets/exits of the exhaust manifolds too.

I'm going to try to do SOMETHING with the intake manifold. The plenum is too small!


So there it is. I will be adding more things if I remember something that I forgot. If I do add anything more, it will be to THIS first post, so check it again from time to time. I'm reciting all of this from memory because my original "Build Thread" was on a site that is now defunct.

I know some of these mods need a little more explaining. Just ask and I'll elaborate. I just wanted to at least get this thread posted. If I waited till I had time to "do it right", it would never get done! It's already taken me too long to get it done!

Good Luck!

Regards,
Eric