vrus

For those that are not aware, a little background information:

In 2003, a short run of SL55 were created by MB which packed a bit more power than the standard 496hp versions. After talking to a few people and making a few calls to Germany we found out that they were in the 520hp ball park. We dont know all of the parts that were different on these cars but we do know that one of the major differences was that this more powerful model had an 80mm AMG Throttle body installed from the factory (standard cars have the 74mm TB). This does make sense since Kleemann was seeing 25 - 30rwhp gain with the addition of an 80mm TB.

I am currently verifying the other induction components (Y-pipe, air boxes, etc) to see if any of those were different also so I will post more info as I receive it.

There are vendors that are currently selling the V12TT TB for our cars, but these require a special adapter plate and modified electronics harness in order to plug in to our E55 engines. I was going to order one of these kits but decided to try this AMG version first because it SEEMS it will be an easier retrofit.

I just received this 80mm TB this morning and it is stamped with an AMG part # and the AMG logo so I am hoping this will be a direct bolt-on requiring only the enlargement of the supercharger inlet and the metal gasket. Unfortunately, I dont have a stock 74mm TB that I can compare it against so I wont know if it will work until I tear the stock one off and try the new one.

I will post pics when I get home tonight. I am a little excited about this since if this works out, it will be a great bump in power for half the price of the V12TT TB kit.

Mad TKD

Thats a good find. Makes sense. More air more power. What did the part cost? and where did you get it?

AMG BLISS

I hope you got me one as well. PM me a part # if you must, I want one too.

MNG

Vrus,

did u have to get new gaskets, or are they the same as your TB...and how about the Y piping that connects to the TB ? can you use the stock ones, or do you require new ones for that as well since the new one is enlarged to 80mm

stevebez

I think we need a bulk buy !!!! OR - get someone to make a bundle of casts from this original ... and we swap over all other bits and pieces from our existing TB's.... anyone up for this ?

I think its only the part connecting to the S/C that is bigger the rest will fit seamlessly to piping etc. It would not have made sense for MB to make a completely new production run of parts forwards of the TB for this small change.

Rgds Steve.

vrus

It was ordered through MB in Germany. It is a special order and can only be obtained with a valid Euro VIN #. Some strings were pulled to get me this first one, but my parts guy is working on trying to get more of them if we get it to work properly on my car.

I believe the landed cost was just under $2,000USD.

Hey Armand,

If it works, I'll make sure one is allocated to you!

BTW, did you get my package in Cali?? Are you back in town or are you still travelling?

You can order new gaskets that were made for this particular TB, but, you can also just enlarge the stock one and save the cost of getting the special one from Germany. As for the Y-pipe, we are still looking into this to see what part they were using. If the stock one doesnt fit, I'll make a custom intake tube for it. More to follow once I get confirmation on these other induction pieces.

vrus

If this works, I'll arrange to buy up whatever remaining inventory they have (there are very few available of these) and make them available to those that want them.

Mad TKD

sounds great. I guess the only thing now is what gains and what other parts are needed to get it working..

Rock

Vic,

I am very anxious to see if you can pull this off without major complexities. Although.................... I'm asking myself, if it is just a relatively easy bolt-on, why aren't other tuners utilizing this unit? I will remain optimistic and postpone my Kleemann order until you play this out.

Good Luck

vrus

Rock,

Awww man... I feel bad now.. The last thing I want to do is take food away from Kleemann (Brandon & Cory). Cory has been such a great guy. He always provides input and responds to my emails when I want to bounce ideas off of him. I was very close to ordering their TB kit myself but wanted to run down every lead I had before pulling the trigger.

I am not intending this to sway anyone away from using Kleemann's solution (FAR FROM IT).. I just wanted to see if there was another way of skinning the cat so to speak.

If you were set on using the Kleemann solution I would say stick with it since you will have them behind you for support should you have a problem with tuning or other issues with the car.

As for why other tuners arent using this part... The only thing I can think of is because they are in very short supply and the tuners cant order them without having a Valid Euro VIN#. It is the same hurdle one would have to overcome if you tried to order anything for the SLR; they want the VIN# first.

I am keeping my fingers crossed that this will bolt-up.. I'll know very soon.

MiamiAMG

Cool, please keep us posted as to the outcome. I would be very interested in this.

eride

this is quite interesting, adding a larger TB reduces low end torque in some cases, but assuming the size of our engine and that amg used it on early production models should mean we'll have a good outcome. looking forward to the results.

vrus

The reason I was hunting down a bigger throttle body with so much effort is because Vadim @ Evosport actually did some testing and found that there was 30in. of vacuum present across the throttle body. When he bored the stock TB from 74mm to 76mm he saw that drop to 15in. of vacuum and picked up 15rwhp 18rwtq.

That means, if the TB could be enlarged more than 76mm to eliminate the remaining 15in. of vacuum we could theoretically pick up 25 - 30rwhp, 30 - 35rwtq. The 80mm TB should take care of that and produce the necessary airflow to the motor.

Like I've said a few times, Kleemann already tested and found a 25 - 30rwhp gain by using an 80mm TB so it is inline with the estimates.

vrus

After examining the throttle body I don't think this will be a complete bolt-on..

It looks as though this unit has the plate opening in the reverse direction of the stock one. The stock butterfly opens from the top and pushes backward. This TB has the butterfly opening from the bottom and pushing backward. Also the EGR tube (air tube at the bottom) is located behind the plate on the stock one and is in front of the plate on this one.

It looks like the mounting holes are similar or the same, but I am not sure that this wiring harness will plug directly into the stock one on the car. I can't for the life of me figure out why AMG would make such a change but, I guess I'll have to try it out to be certain.

First pic is a stock 74mm AMG TB. The rest are the 80mm AMG TB.

DJE55

Good luck getting it to work/fit. It looks like it's a little more work than we all would have thought.

Grumpy666

The vacuum numbers you state in your post don't make sense to me. First, I'll assume that instead of 30, you meant to type 20. No car engine has the cajones to make 30" of vacuum. Second, to reach vacuum levels of 15" to 20," the engine has to be at a fairly low RPM level with very little throttle opening. This is not the way to gauge the maximum throttle size that the engine can handle.

To do it properly, the vacuum level should be measured at WOT at the peak HP/RPM point. The optimum throttle opening would create 0" of vacuum at that point, which means the engine cannot consume any more air. If the vacuum level is higher than 0", there is room to go bigger. I would suggest a target of 0.5."

Do you have more details on Evo's testing procedure?

stevebez

Grumpy666/vrus,

If you measured vacuum at WOT surely there would be resultant vacuum from the air filters resistance - is this why you suggest 0.5 inch of vacuum as a target ? ... would you not need to assess the vacuum ahead and then after the TB to see how much restriction it adds?

Rgds Steve.

vrus

It always is DJ... It always is...

Grumpy,

This was information that I remember from a conversation I had with Vadim over the phone one day. I am almost certain the numbers I spit out were accurate from our conversation but I am not 100% positive. As for the testing method, I don't know how the test was conducted, I only know the results.

Once I have this component installed I wouldn't mind conducting this test to verify if the 80mm is indeed enough. Is vacuum measured before the TB or just after it?

Grumpy666

Yes, theorectically, too much resistance in the air filter would cause reduced air flow, which, at a given throttle opening, would cause a higher vacuum level since the engine is capable of consuming more air than is flowing. BUT, if this is the case then the filter is either clogged or too small for the engine, both of which can be fixed.

I suggested a 0.5" target so that he would know exactly where the vacuum level was. Say, for example, that an 80mm TB gives a vacuum level of 0" at the WOT/peak HP point. If he were to install a 100mm TB, the vacuum level would still be 0", but the TB would be way too big, and the car would drive like a turd. With a 0.5" target, he would know that the the TB is sized properly for his engine - that last 0.5" of vacuum would not add very much to the output.

There is no vacuum level prior to the TB - the air is either at atmospheric level (w/o supercharger) or at the boost level of the S/C. Engine vacuum occurs between the pistons as they travel down the cylinder on the intake stroke and the first restiction in the intacke tract (the TB). If the pistons displace more air volume than is flowing, vacuum will occur. If the TB is wide open (essentially no restriction) and enough air is flowing to match the pistions displacement, then the intake tract will be at atmospheric level (0" vacuum) for a NA engine or at boost level for a S/C engine. If, at WOT, there is still a vacuum level in the intake tract, then the TB is still a restriction and needs to be sized larger for maximum performance (assuming adequate air flow prior to the TB).

You can also use this procedure to determine how well a S/C is sized for an engine. If the boost drops off as RPMs rise, then you need to spin it faster to keep up with the engine (assuming a positive displacement S/C).

eride

wow i could imagine the renntech airbox made to fit an 80mm throttle bottle would be stelar.

SLcharger

I would recomend using K&N filters. Pressuredrop is close to nothing in those filters.

stevebez

Any luck vrus ?

Rgds Steve.

vrus

One step closer now..

I mapped out the pinouts on the stock wiring harness and the pinouts on the 80mm TB.. They are very different!! I am looking at a way to get the 2 of them to mate together.. I either have to take apart the harness on the new TB and put the pins into the order that the stock wiring harness is expecting, or I have to make an adapter harness that goes inbetween the two of them.

Once this is done, I need to pull the stock TB and test fit the new 80mm TB to make sure it will mount up. I've tried to locate a stock TB somewhere so I can physically compare them, but no one seems to have one available (I didnt think they would anyways). If it doesn't fit, the plan is to order the MB Part that goes between the supercharger and the TB. This piece is also different on the early model SL55 and has an 80mm bore. It's a $400 part, so hopefully the mounting holes will line up and I just have to bore out the stock piece.

More to follow...

stevebez

vrus,

Can you not replace the new 80mm TB's electronics with the OEM 74mm TB's electronics ? This will ensure that it fits neatly in existing wiring / ecu settings.

The more I look at this the more it seems boring out the OEM part is a better bet all round.... How much do you think we can open up the OEM TB ?

Rgds Steve.

vrus

Look at the first picture of the 80mm TB above. The black coiled wire that is running along the top of the TB is the wiring harness that goes from the TB to the car's wiring loom. The wire loom's receptacle on the TB side is wired differently than our cars. Changing it would require opening up the entire TB assembly which doesnt make sense when all that would be needed is to rearrange a couple of wires in the loom.

But, since you mention it, for sanity sake, I will try to disconnect the wire from the TB side and inspect the pinouts there to make sure they didnt cross-over any wires. That would be a pleasant surprise if they did, because then I would just have to purchase a stock wire loom piece and use that.

I disagree.. Boring the stock TB is not the best answer; it is the simplest and easiest answer. The stock TB is 74mm.. The maximum you can go is 76mm based on the wall thickness that is available.

With a bit more R&D upfront, this 80mm TB will work and provide much better results. There is definitely effort required to make it all work, but, I think it will be worth it in the end.

BTW.. Remember 1 thing... Even with the Kleemann 80mm TB kit, you wont get optimal results because they provide a CNC adapter that goes between their 80mm TB and the STOCK 74mm SUPERCHARGER INLET. In order to see the best results, you would have to still bore the supercharger inlet to 80mm so that it matches the outlet of their adapter.

I am not 100% clear on whether they do this to the cars they install at their shop, but, if you buy the kit from them and get someone else to install it, that is another task that needs to be done.