I really didn't do anything special. Just put the 82s in where the 74s were trim where needed and bolts everything together. The only place I used rtv is where the top of the intake bolt to the bottom. Just be extra careful bolting everything together. The bolts don't need too much torque and very easy to strip.

And I didn't use any velocity stack

 

FWIW they open at a clean 90 degree opening.


Also, for the guys that have done this...what ignition timing values are you guys seeing at idle? Mine is around -9, which isn't correct to me, but I'm guessing I wont have much of a choice until the car is tuned. My guess is that the only way the ecu can maintain a low idle (~750rpm now....i don't see 600rpm anymore) is to pull timing and bog itself. Vacuum used to be around 17 (when warmed up) but now it's around 15.


Also...cold start? Sweet Jesus Just when you thought a cold start (with headers) with the car reversed against the wall of the house couldn't get any louder....

 

Hi Blkrokt.

Just to confirm, the MB part number of the throttles is A2731410325?
I assume I just need the gaskets that go with that.
Any chance you can measure up the new throttle mounting plate, with positions of all holes and threaded mounting points.
Getting anything to South Africa is expensive. If I can get a drawing, I can machine up my own mounting plate. Will just get the throttles from my dealer.

 

I see one request already for measurements on the throttle body plate.

In this 3D world a 3D image scan would be ideal. With an image you could CNC machine, 3D print or create by hand. No idea on the cost but maybe Savage-wp should see if a scan be arranged.

 

Maybe we should stay on this guys good side and get the Group Buy sorted out first (possibly, still waiting to hear back) before we go passing around specs and making copies of his plate? I'm just not interested in doing that at any point really, it's certainly not my place to do so. Sorry. Maybe I can pass along his email address and you can ask him yourself.

 

ya that's what i figured. to fully take advantage of the increased airflow you'll need to have a big throttle body tune.

 

TBH I think my issue is that there's an internal vacuum leak on the plate. Otherwise, everything else goes via the MAFs - ie although power may be marginally un-optimal, the car should still keep it's manners etc It's a bit long-winded to have to order the 550 series gaskets in my country, but I'll use 82mm 997 gaskets from a Porsche tuner.

I've got a proper plate now anyway so I'll be doing a more permanent install this weekend hopefully anyway. Initially I just wanted to see if it could be done, hence the big hammer and hacksaw approach. For guys that have installed Olies kit, did you use the RTV sealant anywhere? Seems a bit odd that he supplies it when the manifold belly pan doesn't need it on the stock set up, so I'm wondering what the thinking is for this kit

Also, is anybody able to share their idle vacuum (after 30 seconds of engine running or on a warm engine) and idle ignition timing?

For anybody curious, the peak airflow gains from ported stock throttle bodies are 6-7g/s or ~0.8 lbs/min and from bone stock throttle bodies it's 9-10g/s or ~1.2 lbs/min. I did some testing over the weekend and these are the figures from my car (way too much time on my hands at the minute). Butt dyno definitely picks up a small increase in power up top for sure.

 

It's for the intake manifold "clam" - goes between the upper and lower parts per WIS

 

oh really? I've never used any before and i've opened it countless times. Plus, it has a rubber seal in place anyway, which is another reason why I thought it didn't need it. I'll apply some RTV over the weekend then.

How are you getting on with yours?

 

Yep, WIS calls that lower part the "collector" and to replace the damaged seal bead with Loctite sealant 5970 which is just RTV.

Got the two new OEM TBs in the past week. Been too busy with work to get started. I'm away for the next 3-4 weekends, so I don't see it going on until mid-Sep. I've got to get the wing done first (maybe this week if I'm lucky), then this is next + dyno tune.

 

Learn something new every day... i guess this is mine for the day

Fair play man, good luck with the install. Please don't forget to log airflow before/after

 

you currently have no gasket between the throttle body and the mounting plate? thats bad news. RTV or a sheet of gasket maker should do the trick

 

Yeah no, I actually did have RTV but thought it might have been the cause of a vacuum leak (vacuum leaks and my car seem to be the theme of 2017). I tested the seal of the RTV via a water test but it was fine tbh. However to rule out any doubt, I managed to source a pair of the correct gaskets from my local MB dealer (thanks BLK for the part number ) and I did the install over the weekend.

After the install, it didn't cure my vac leak, but at least I'm confident it's not an issue with the TB set up finally. Upon further investigation, my PCV bolt got mixed up/lost and the wrong was being used (too short) which wasn't clamping the pipe firmly. Go figure. Needless to say, I ordered a new bolt (2 actually - 1 for when I inevitably lose the first one) and it'll be with me by Wednesday. Part number for those whom drop theirs down the back of the engine bay - A 000 990 70 11



I've also been getting a lot of PMs with a similar theme of questions...for reference, here are the answers to the most commonly asked questions:

1) The velocity stacks - you will have to get those custom made or find a place that sells them. I asked Kleemann for these over a year ago and despite me spending thousands with him for his cams...he declined. I'm sure it's doable and will be worth a few hp, but it's not something that I can be bothered to do.

2) Part number for the TB bolts: A 009 990 28 04 - you wont need loctite. I torqued mine to 9nm - this might not be correct though.

3) I've found that RTV isn't needed on the lower bellypan/clam (I've opened/closed it probably 15 times now), but if you want to thorough, apply a light coating of engine oil around the rubber. I don't think there's a part number to enable you to replace it as it seems to be bonded to the casing.

4) Lower clam/bellypan bolt part numbers: A 009 990 30 04

5) Torque settings for all of those mini bolts on the manifold are 7nm. Do not over-tighten much more than this as the material is very soft.

6) For those of you that have had limp mode after starting the motor, check your connection at the harness from the main engine harness to the mini TB harness - mine has been a bit rubbish in that area too, so that can be the case for others. Clear the code and restart again. It'll eventually go away.

7) If you get a P0106 code - you have a vacuum leak. Check all hose connections and hopefully it'll be something simple/silly like that.

 

oh look! BFH!

 

I wonder if 82mm TBs will help take advantage of my port n polish.

 

More like cams tbh, if that.

Out of curiosity, what's your airflow reading via the maf at high rpm?

At a guess, air speed has taken a hit...but it's hard to say without any data.

 

Any updates BLKROKT

 

Found the vendor on eBay but the price is at $1100 +$100 shipping. Thought he went down to $900?

 

Just spoke with Oli via ebay. There doesn't seem to be a need for a group buy. He was willing to sell me the plate separately for $700. Than he offered me a even lower price for it. So now we just need to find good deals for new TBs. Know of any deals out there?

 

My pain = knowledge shared for the community.

Guys - when sourcing throttle bodies, you need to perform a very simple but critical test. Many of these are going to be used/old and may have legacy issues.

The test is simply to lift the TB unit into the air and hold it under your bedroom light. Press in the flap of the throttle plate. The small amount of light that could see around the edges of the plate should more or less completely disappear as the plate almost perfectly seals the bore of the unit. I can't tell you guys how much of a blind alley this issue lead me down. In the end after countless (and I mean countless) tests to work out the problem, it turns out, I got screwed on not one, but both TB units. If you don't run healthy units, the car will have a brutally loud cold start if you have headers, idle will be insanely chuggy and loud and the car will generally run like crap and hit limp mode, often with powertrain fault codes. Not nice.




Right, now I wanted to update the thread to show my ghetto velocity stacks and to share some data.

I sourced a pair of generic 3.5" velocity stacks from ebay. I used this listing, but I'm sure there will be a comparative listing in your country wherever you read this:
http://www.ebay.co.uk/itm/UNIVERSAL-...oAAOSwcdBWTpG5

Below are some pics of how they were when new with some annotations.



Hmmm...long necks wont even fit into the belly pan housing



Nor will the v-stacks even sit over the TBs





Exhaust pipe cutter



Slow but clean



Nice clean cut, but ultimately wasn't enough



This bit caught me off-guard and meant the belly pan wouldn't seat...ahem.....more cuts were needed to the v-stacks

 

Lots and lots of trims needed


Got it quite low, but not low enough...there was only around an inch of space between the belly pan and the face of the stacks when the intake assembly was closed up


I made more cuts to the neck of the stacks and compared them to the stock units against a flat surface, just to make myself feel better that I wasn't about to ruin my car and choke the damn thing


Finally, got them as low as possible and that means around 1.5" of clearance

It was largely trial and error/using the force as I went along to get all the trimmings done in the right place etc. I didn't initially think I'd have to make as many cuts as I did...but there you go. I epoxied the v-stacks to the throttle units.

Now having thought about it, I can understand why two throttle units are used...because of the damn clearance to the belly pan. Why Mercedes/AMG did this rather than a more conventional in-line set up, I'll never know, but I'm sure there must be something of a good reason. I guess this is why the misconception of the twin stock TBs being able to provide enough airflow are proven wrong. I mean, sure, if the twin TBs were mounting inline to the intake pipes, then sure, bigger units probably wouldn't improve airflow at all, but when the units face a wall in a very confined space, I can totally understand why the bigger ones make a difference.


Needless to say, did it work? Yes and I'm bloody glad it did, because it took me lots of time and effort to get these fitted. Peak airflow gains are up by 4-5g/s. However, the nice thing is that the general pedal feel has been greatly improved because it's ingesting more air easily at lower rpm, resulting in a faster car. For instance, the motor picked up an average of 15-20g/s of airflow from 4500rpm to around 6300rpm. It's more consistent up top. This is just by adding the velocity stacks. The big TBs vs stock ported united with the smaller v-stacks is actually pretty similar in terms of what they flow. I guess the smaller diameter units suck as much air because they're aided by their v-stacks. The big TBs aid in general response and a slight increase right up top. When you pair them with v-stacks, then you're in business. My 60-80mph sprint has come down by 1 tenth after fitting these v-stacks. Still loads more to come from this motor I'm sure.

Now...if only I can get my car to actually have full throttle at 5000rpm when I put my foot to the floor....ahem...but that's something for another day I suppose

But anyway, so there you have it, you've been advised - go fourth and get busy with the dremel.

 

Good to know about the throttle bodies. I'll have Shardul inspect the TBs prior to shipping.

I found the same velocity stacks for us Merica citizens.

https://www.ebay.com/itm/3-5-UNIVERS...VYN~Bb&vxp=mtr

 

i'm liking where this is going.

 

For anyone looking to do this I have some pricing for you,

Oiles-rus @ eBay will do the plate alone for $530 shipped or the Package (that BLKROKT got) at $1100 shipped. Oiles-rus advises to pursue the throttle bodies locally to save on postage and confirm functioning of the throttle bodies.

Shardul @ UPD will do $315 shipped for a pair of used throttle bodies. He will inspect them prior to shipping.

Totaling to $845 for this project not including gaskets or the velocity stacks.

*Note I am not affiliated with either vendor*

 

not bad...i'm game!