Autocross season 2 about to start for my 87 300D - PeachParts Mercedes-Benz Forum

Johnhef · #1 04-17-2008, 09:47 PM

First date of the season is April 27th- I wonder If I'm going to have any other diesel competition this year or will I have to shame the gassers again

I'm about to order track tires for it to go on the lightweight CLK wheels I just picked up.

Can anyone reccommend a site that sells a good pyrometer setup? prefererably by VDO.

Any and all tips to squeeze more power out of this thing would be great- currently running no alda and about 14psi or so. I think after getting a pyrometer the next step would be to turn up the screw inside the pump right?

One last question, the air flap box under the air filter housing, does it actually hinder anything at all if no other emission devices are on the car? I may remove it in favor of a 123's intake tube, I've seen a similar setup recently that fit.

Wish me luck!

bgkast · #2 04-17-2008, 09:51 PM

egauges.com seems to have good prices for pyrometers.

babymog · #3 04-17-2008, 10:00 PM

I can't imagine the air flow sensor does much if any measurable restricting, you can always run a set-screw through it to keep it open. On the other hand, weight up front is weight to lose.

GREASY_BEAST · #4 04-18-2008, 01:49 AM

Is intercooling on the menu? Propane might get you something for cheap if thats what you are after, but more fuel and more, colder air should probably be priorities number 1 and 2. Within the confines of exhaust gas temperature limits (which are low) and head gasket limits (which are exceedingly high)... Don't know much about the 603 specifically, but I gather they are capable of some power... don't know precisely how much with stock IP though.. Another area that should theoretically net some benefits might be injector work, specifically an extrude hone or EDM operation...

For autox you probably want to avoid anything that will delay spooling of the turbo as well, so exhaust removal or enlargement, as well as intake restriction removal should help some..

Johnhef · #5 04-18-2008, 06:52 AM

I do have an intercooler from a 202 that will fit behind the lower front bumper- still have to figure out piping and such, maybe for next year.

I was thinking about exhaust- I have an extra downpipe from a 617 and to the eye it looks like it would bolt up, but I haven't tried yet. I dont want to destroy the exhaust on it now by cutting anything.

Zeitgeist · #6 04-18-2008, 01:21 PM

How have you setup your suspension for X-cross?

Johnhef · #7 04-18-2008, 11:11 PM

Bilstein sport shocks and H&R springs. new ball joints, sway bushings and LCA bushing up front.

Spoke with Luke today and ordered the tires from Tirerack. Should have them mid next week.

Zeitgeist · #8 04-19-2008, 11:05 AM

How is the ride with that spring/shock combo? I'm preparing to dump a chunk of change into chassis upgrades for the wagon, and would prefer a final product that's equally at home on the street or track.

I used to run the same 17" (ET 34 & 37?) rims as in your pic, but hated the bump-steer effect, presumably from the incorrect offset. I've since installed the 16" versions (ET 30 & 34) and have been very pleased with the ride and handling.

Shawn D. · #9 05-14-2008, 12:21 PM

Quote:

Originally Posted by Zeitgeist

I used to run the same 17" (ET 34 & 37?) rims as in your pic, but hated the bump-steer effect, presumably from the incorrect offset.

That's a scrub radius issue, not bump steer. Bump steer is a change in toe as the suspension moves up and down.

Deni · #10 05-14-2008, 04:32 PM

Oh boy, were the others even trying? You've got a GREAT place in that list! I bet it has more to do with the driver than the car. The 16 valvers should be about perfect for autocross.

omegabenz · #11 05-25-2008, 06:35 PM

When is your next autocross? My area has a couple the first weekend of each month in my area. I may try to head out.

I just put these camber plates from RDM TEK on my 500E, stiffened up the front end a bit, increased turn-in feel, yet still rides great on the freeway:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=220237534919

I think I may go with their rear camber kit too because Im running 275/35/18 tires in back and I don't want to wear them down too fast, I have about -3.5 degrees in the back.

Johnhef · #12 04-20-2008, 08:18 AM

Its defintily a bit more stiff

over the stock setup of course but not unbearable in use as a daily driver. You sure do get to feel all those minor bumps in the road. I havent noticed the steer problem you mention though. I went with those cause I had a free set of street tires in that size with a pretty stiff sidewall to use for last year.

Johnhef · #13 04-23-2008, 12:13 AM

Trial fit the new wheels on it tonight, quite a nicer ride too with that extra bit of rubber. I came home to find the new tires waiting for me on the porch so I'll be putting them on tomorrow.

I had some extra time after work tonight so I wanted to try something. Ever since seeing a youtube video of a 300SDL with a straightpipe and thinking it didnt sound too bad, I've wanted to try it. I've also been wondering if my exhaust is starting to plug up at all. I had a downpipe from a 617 engine, so after removing the complete exhaust off the car, I bolted the 617 downpipe on.

The upper end fits exactly the same, but it's slightly taller, meaning it sits lower then the original pipe. On a normal car this probably wouldnt be a problem but with mine being lowered, it did scrape over speed bumps. I added a 45-degree turn down at the end of the downpipe and fired it up. God what a racket.

We took it out on the road to see some results, but being in Germantown MD aka cop central I couldn't really push it too hard. Had a cop directly behind me for about a mile as well (plus his windows were down, d'oh!) he passed without saying anything to us as we continued on to the interstate. I did notice a few things (besides the noise!). The boost pressure obviously builds up extremly fast now and in all gears to what would be (on my 0 - 15psi gauge) about 20 PSI and probably higher but the gauge may have limited itself from going around a second time. Normally 14 PSI is max with pedal to the floor, in 4th gear it will slowly climb slightly higher to 16-17. I couldnt discern if the car was actually any quicker though.

I was contemplating on swapping out my exhaust for this short pipe on the fridays evenings before the autocross sundays to try and gain a little advantage but, without some sort of noise reduction I think I'm going to scrap that idea.

apologies for the poor quality image and video, I only had my phone with me, but you get the idea

http://www.youtube.com/v/M5w2rGhnsJM

Johnhef · #14 04-27-2008, 09:20 PM

Still waiting on the results from todays event to be posted but I think I did pretty well! Our course today was a large outer loop with a skid-pad type circle in the middle you had to encircle twice- I was a little rusty in the morning since it had been last november since I had last run, but the afternoon runs showed improvement, gaining almost 4 seconds over my first run in the morning. I managed to stay very close to the other gasoline models and even beat a few of them as well! I'll post the times as soon as they are released.

This was my first time with the new light CLK wheels and track tires. They were quite an improvement over the street tires I used last year.

iwrock · #15 04-27-2008, 10:16 PM

That W124 looks awesome flyin around the corners....