mahunt

I've always wanted to post a picture of the RENNtech carbon fiber modified air boxes, but have been too lazy in the past.

The butterfly diameter of one of the 2 stock throttle bodies is 69 mm; which gives 3739.28 square millimeters. Unfortunately, the factory air intake is hindered just aft of the radiator. Could someone post the outside dimensions of the necked down part of a V12 OEM air-box.

RENNtech modifies the front part of the air intakes and the narrowest section is 95 mm by 45 mm; giving 4275 square millimeters of area.

In addition to the greater volume of air, the modified intakes don't have the flange that protrudes past the radiator support opening. The flange always hangs up on the radiator support opening and tears out the support opening surround's push pins. The RENNtech air-boxes easily slide into and out of place with no drama.

I thought some folks would like to see the air-box.


RENNtech modified SL600 intake.

Fabio D

wow mate!! Never seen this besote, you have some more pics? What other mods made renntech to this engine?

Fabio D.

mahunt

This is the passenger side air intake. The driver's side looks pretty much the same, but I can post a better shot of that side.

My car isn't a RENNtech, I was just able to get the intakes separately from a guy who was parting one out a long time ago on eBay. It was a pre-96 V12 and the modified ECUs were for sale as well, but they weren't for my year car.

I do have a resonator eliminator (sound pipe) on the car, but it's a custom stainless steel one from Japan.

If you haven't seen it, the RENNtech option sheet provides prices and horsepower improvement figures for V8 and V12 upgrades. It's nice to dream.

AndreasHannover

AMG replaced software, intake, air filter, expanded the intake manifold and replaced the camshafts for 10% more power. Renntech creates 5% more with a little more cross-section, I'm thrilled

Fabio D

can you post some other pictures if you have, and very interestes in the sound pipe (resonator deleat pipe) cause my resonator was a little rusty now. Were can i buy it?

thanks in advance

Fabio D.

mahunt

The resonator eliminator for the V12 cars is different (larger at the head pipes) than the V8 or 6 cylinder cars. I have a spare V8/6 cylinder sound pipe.

IF your SL is not a V12 AND was built before 1999, the sound pipe that I have WILL fit your car. Because the V8/6 cylinder sound pipe ALSO requires the larger muffler (V12 size), you have to find a larger muffler. I have my original V12 muffler which can be used with the V8/6 cylinder sound pipe.

The first photo shows my stainless steel V12 sound pipe and (for real) AMG muffler. I currently run this setup.

The second photo shows my spare V8/6 cylinder sound pipe and my original V12 muffler (original resonator is underneath). The sound pipe replaces the resonator.

If you have a V12 and need a replacement factory resonator, my original (in good condition) is available.




Andreas,

AMG modified V12 cars produced a bit more than 10% horsepower than the OEM MB cars. RENNtech states the CF intake was good for 20 HP which is about 5%. If you doubt the figures, please take the matter up with Hartmut Feyhl at RENNtech. I'm sure he'd love to hear your opinion.

Fabio D

My SL is a v12 from 95’ id love to install the sound pipe (resonator deleat) i want a little bit more sound than factory, as well the amg final muffler is a little hard to find. You have the amg body kit as well? Or how it looks the amg tips on a normal bumpers? If you have any contact to buy the sound pipe to my sl600 i apreciate your help mate!!

Fabio D.

mahunt

The stainless steel V12 sound pipe came from Japan (not very easy to obtain from Yahoo Japan).

My car has the Sport (AMG) body work which you would need for the AMG tips to fit seamlessly (or modify your existing rear bumper cover).

The sound pipe provides a slight snarl at engine start and just a hint of engine note during acceleration. Steady state driving (cruising) sounds just the same as OEM. The V12 is naturally a very quiet engine.

Here's 2 more pictures of the AMG muffler. At the top of the first picture you can just see the single large oval exhaust (but still twin outlet) on my car.

mahunt

More RENNtech inspired mods on my car include the rear suspension.

This might be my favorite upgrade on the car. The boots on the heim joints keep them from normal exposure.

The silvery pipe barely seen in the background is the stainless steel sound pipe.

That's about it for RENNtech stuff on my car.

I did used to have the larger rear sway bar (3/4 inch vs 5/8-ish), but it was really for the smaller pumpkin on the V8/6 cylinder cars. The sway bar swap was not an easy task.

AndreasHannover

Hallo,

You are right, it is 11%, but i dont think it makes a big difference. This is the modified part by AMG, i think it would be much funnyer to listen Hartmut Feyhl and Hans Werner Aufrecht talking about such things.

mahunt

Hmmm.

11% of 389HP is 43 for a total of 432.

The AMG SL70 produced 489 HP while the SL72 was good for 500. If that wasn't enough, the SL74 made 518. Which M120 engined R129 bodied version are you referring to? I had heard that there was an AMG head and cam kit produced for the regular 6L cars, but I haven't seen anything. Some folks talk about using the cams from the straight 6 AMG C32 cars, but you'd have to have access to two engines.

These are all very rare AMGs, do you have one?

I've never seen that photo of the driver's side V12 intake, do you have more that you can share?

AndreasHannover

In Europe, we messure a bit different. The standard V12 has 396 HP, the small AMG with 6 liter named SL600 6.0 but replaced software, intake, air filter, expanded the intake manifold and replaced camshafts has 440 HP. So from 396 to 440 HP is about 11% and yes, i own such a car. AMG modified the intake with some other parts, too, but i really dont think it makes such a different.

AndreasHannover

This is the standard intake, you can see the rough, unprocessed edges.



This is the AMG intake, the edges are milled away and smoothed.




We own both the normal V12 and the small AMG V12. If you saw all the other details as well, you might not believe what a simple plastic pipe is supposed to do either.

mahunt

So you ARE talking about the AMG V12 6L cam kit engine.

Nice photos of a very rare AMG upgrade.

Does the engine have the AMG tuning sticker on the engine? Any paperwork?

I couldn't help but notice that the intake photo you provided in the prior post seems to show the edge of an all aluminum radiator. As in no plastic side tanks.

I've had my intake off twice. Once to refresh the intake gaskets and injector O-rings and the other time to powder coat the valve covers (with a valve cover gasket replacement of course). I took that opportunity to port match the intake manifold to the intake intermediate adapter and the adapter to the head. If this did anything, I can't say. I also port matched the throttle bodies to the intake elbows and smoothed out the throttle venturi. Once again, no discernible difference.

I suppose AMG provided a resonator delete as well as a matching muffler?

Per typical hotrod practice, a little better breathing and exhaust improvement provides modest gains on an otherwise stock engine. The stock air intakes on the V12 engine must be as restrictive as they look. RENNtech lists the resonator eliminator as a "sound pipe" and may only make the exhaust sound better with no listed HP gain. I do like the slightly improved sound of the modified exhaust over the absolute hush of the stock setup. The chrome tips provide a little flash on an otherwise understated car.

Here are a few more photos of my RENNtech intake and the engine.

AndreasHannover

Sharp eye. I needed a new cooler and it was not present at Mercedes or OEM, so i had to have built a new cooler.




i converted the car for running with propane, so i renewed tons of parts. The AMG muffler looks more or less like the OEM one with an other tailpipe. It is not louder than the original and i am happy with it. I prefer silent cars.




There is some paperwork, a fancy badge and a lot of parts. I guess the camshafts are the important things bringen some additional horses. The rest is some nice craftmanship.

mahunt

Great minds think alike.

I live in Florida and the sun is a little hard on the plastic interior parts. I got the AMG door locks about 10 years ago and the proper floor mats 5 years ago. I would have gotten regular floor mats, but I could only find the AMG ones with the correct attachment buttons and extra coverage for the foot-well. My original pedals were a little worn when I originally got the car and were the first upgrade.

I was lucky enough to get the wood grain speaker cover and door pull surround back in the day. I wish I had the presence of mind to also get the burl wood overhead console, but my original cover was still pristine at the time. I like the speaker cover as it completes the wood trim Nike "swoosh" and I don't have to clean it like the old fabric cover.

Did your car come from Japan?

AndreasHannover

You mean this part?



I changed the steering wheel, the clearcoat from the original one was broken. And i have replaced the only part that i guess is an improvement at the last models. You will notice it, if you have a 97 modell




You are right, the car is a re-import of Japan. Depends on which region, Japan is a hot place, too with all the effects on cars. I like cars from Japan, japanese people are more german than the German: They like there cars. Would you say, American cars from the south, not salty aera are in similar condition? For me, it looks like there are not so much enthusiasts in the US for these old cars.

mahunt

Yes that is the overhead console you have circled. Hopefully, yours is in good shape.

I had to swap my steering wheel and shifter knob for the same reason you mention. They are the 2 most touched parts of the car and see as much use as the seats.

The steering wheel you show has the AMG style fatter grip, but I would guess you had the same feature on your original. As for year to year upgrades, my favorite would be the 98 (one year only) stitched leather steering wheel airbag. I do like your original AMG speedometer.

I got the stainless steel sound pipe and AMG muffler from Japan. I agree that they are enthralled with the R129 cars in general and especially the AMG cars.

I sort of live near the gulf coast (the car has certainly made it to the beach), but my car doesn't suffer so much from the heat as it does the sun. The cars are well made and are all weather prepared by MB, You don't really see a rusty R129 ever. I'm sure there are rusty ones, but it would have to be poorly treated by its owner. In addition to sunlight, my car has seen a lot of usage (260K miles worth). And yet, with diligent care it can seem as new. The plastics don't hold up very well, but everything else does. When I take the car to the dealership for service, they always comment on the condition. Everything gets refreshed when tired or broken.

As for Americans and cars. We used to be a car loving/driving country, but that is changing. People here now buy and drive more trucks and SUVs than cars. Some kids now don't even bother to learn to drive (and have no desire to drive) at 15 when they come of age like they did in the past. I have twin boys and taught them to drive a 4 speed (manual) 1967 Camaro SS 350 when they turned 15. They drove that car all throughout their teen years. After college they each bought trucks (at least they know how to drive stick).

As for the R129 and Americans. I think people believe the car is a sports car (which it isn't by a long way) and find it lacking. The SL is a cabriolet GT and excels on long road trips where comfort and open air driving are appreciated. My car was my daily driver when I first got it and it wasn't until I retired and started going on long trips that I fully realized what a great road car it was. I love the way it covers large distances with no compromise in style and comfort. Also, a few folks thought the car would be an instant classic and never drove them expecting them to always rise in value (what a pity). Cars are meant to be driven and enjoyed, not garaged and polished.

AndreasHannover

My overhead console works, repaired it once and avoid to touch it. The mirror is one of the next construction sites. In Germany, the R129 has a big fan base, so people looking at Japan and US for such cars. My painter always runs away screaming when he sees a car from America. Thats why i asked. We visited US three times (OK, not US but Las Vegas), and for me there are either new cars or burned, old ones. But this is for shure not representive.

The steering wheel is after market, there was no special AMG wheel inside. And this is good, AMG covered the body with leather which shrinks while aging and irreversible deform it. Pictures of a SL60, sold because of failure in design, 4 cylinders missing :





I have had some R129 but never seen one with an original stitched steering wheel. But greetings to the folks never drove it, would dispose the old cars. Next time, when you take the car to the dealership for service let them look at that (or repair it with some good glue by yourself)

mahunt

Ahh, the ever cracking vacuum distribution block.

Even the new ones crack in about a year. After replacing 3, I just used epoxy glue on the last one and check it periodically for leakage.

You are fortunate to have the leather interior as it holds up WAY better than the vinyl. The trick to leather is taking care of it BEFORE is dries out and cracks. Use quality leather products like Lexol cleaner and treatment. Of course there is no substitute for saddle soap. Just keep leather clean and nourish it every six months. It will outlast vinyl.

I'm including 2 glamour photos of my car so that you can see that not every American owned R129 is a basket case. Even one that has 260K miles on the odometer.

If you look in the background of the second picture, you will see that we still have the red 1967 Camaro RS/SS350.

Notice anything particularly European about my car?

AndreasHannover

Leather exclusive was a requirement for buying this car. I saw a documentation on TV how this was made, it was amazing. The whole thing is an European car, i guess you think about the turn signal without side marks? And it looks so much better without the headlight wipers which are mandatory in the rest of the world. The last R129 i saw in Vegas had a frontbumper held by gaffa tape with peeling clearcoat, looked much more sad than your happy car.

The engine is bullet proof, 260k miles is no problem. Did you ever have to changed the front cover seals? At the standard V12, i had to change them, the AMG is still dry. Knock on wood.




Just bevor completely off topic, some small AMG details

mahunt

I looked at 2 SL cars before I settled on mine.

It's appalling how some people take care of their cars. One of the cars had the leather interior and there were cigarette burns on the dash. I always thought I was getting a $140K car for $21K and treated it like I got a great deal. Some folks get their cars for much less and treat them like they are $4000 throwaway cars. From what you report, Las Vegas sounds like a mecca for that kind of thinking. I've also seen some west coast cars interiors where it looks like the tops are never used, rain or shine. I suppose this really happens everywhere.

By 1997 MB figured out what was wrong with the sealing on the V12 and fixed everything. The intake manifold leaks (metal intermediate plate), the valley breather and all the front end timing cover leaks. If you watch the "Victor the Mechanic" YouTube videos, he fixes all these issues and uses the updated parts that come on every V12 built after 1996. Don't get me wrong, there are still A LOT of things that can leak or go bad on the cars, but the worst leaks on the V12 were fixed.

I really like the photos you keep posting, it's so rare to see an authentic AMG.

Back to my car.

The clear corners just looks so much better on the silver cars. I know they are European, but the items I'm hinting at are at the rear. Look at the rear wheel arches and think TUV.

AndreasHannover

The rear wheel arche protector comes at factory if the 18" AMG wheels are ordered, you upgrade them? I think the German TÜV will not punish missing ones, it's more of a protection for the fender. You are right, Mercedes changed the sealing of the front end timing cover and it would be nice, if i have dont need to change them at the AMG, too. Both are year 97. The second white one is the black sheep of the family.



Sometimes, it seems they play strange things with each other




I can't find something interesting named Victor the Mechanic on youtube, only very strange things. The SL 60 had some realy special AMG parts. The wood was birch. I had a pricelist of these days, it is frightening what the first owner was ready to pay.

Frank_S500

If you polish your brake discs a little, your rims might be thankful and let you to go straight over the Autobahn.. .

CU later, Frank

AndreasHannover

It's enough for a V8 The pictures show the condition immediately after purchase, before the overhaul








Breaks? Peanuts.

CU