Attached is a pdf tutorial for the 74mm Throttle Body Upgrade. If there are question or mistakes, let me know, I'm too lazy to read over my own tutorial.

This is for the N/A, sorry SRT.

Hopefully someone will post a dyno for this mod.

EDIT: the pdf is updated

 

The last step is crucial to this job being executed correctly. Be safe out there

 

I'm hoping I can get Jerry or Clint at Eurocharged Performance to put it back on the Dyno to determine what Hp change to achieved with this mod. Jerry is still off with his wife with a new baby and Clint is about to do the same thing. I still have lots of projects to do( front brakes, brake lines, etc. I'm going to take it out for a few minutes at lunch just to see if I can tell a difference in power or sound,etc.

 

I would not recommend doing all this work without replacing the O-ring, any small air leaks would probably not make much difference but why risk it. They never fit the same most times. The O-ring used is very soft and appears to have been 3/32" by 3 3/16" outside diameter. The regular O-ring most easily purchased is harder and would not squash like the OEM one. The trouble is these normal type O-rings may not stand the constant heat like the OEM ones. If a normal material (Nitrile) O-ring was used a 3/32 by 3" inside diameter may work. I'll think about that problem, but probably buy the OEM part, part # 05102933AA, this is $17.35 list and $14.60 net in Canada. Not in stock at my Chrysler dealer but came in after just two days.
Why spend $100 on a TB and save $10 on a O-ring or if your local mechanic did it you would think he did a half assed job.

The method of removing the throttle body originally spelled out in the PDF is asking for breakage of the molded clips. It is not the recomended method at all. I would unlock and remove the ring that locks around the MAF and not bend the tabs that are a part of the clip, these are plastic parts and we would not want to break them. These tabs are not designed to bend, they are locks.

I warmed up the breather hose attached at the bottom driver side of the elbow with a heat gun a little and it came off easily.


This photo shows the method to release the lock ring.



This photo shows the ring unlocked. The ring can then be removed from the MAF.




After removing or at least loosening the lock ring, pushing these two clips in the directions indicated allows the MAF unit to come off in one piece and that is better than separating them. Actually pushing down on the bottom one allowed the unit to swing out and away from the throttle body.



This view shows where the clips snap onto the throttle body.



A view of the 74 mm Throttle Body, Mercedes #A1131410125 attached to the OEM MAF unit. when reassembling the MAF to the throttle body make sure it is square or it will be hard to attach the clamp shown in the top picture.




New O-ring, #05102933AA, Mercedes #3059970345


The larger MAF next to the OEM MAF showing the extra 3/8" (approx) larger bore. The sensor in the OEM unit was reinstalled into the larger unit. The Larger unit shows the sensor loosened and askew. The screws holding the sensor in place are the five point (not the normal six point) Torx TS style. These are the tamper resistant style and baffled me until Beaner said I could use a small flat head screwdriver on them. I had a tamper resistant flat head bit and it fit like a glove.

 

I would agree with you, but when I pulled the last bolt out there was no resistance from the gasket. I did put high temp bearing grease on the flange, but there was no stuck residue from the gasket. I'm going to disconnect it again and inspect it just to make sure. When I undid the plastic part I disconnected the 3/4 od hose from the valve cover and rotated the whole assy out of the way without undoing the connectors. Installed new TB, rotated back in place and connected the hose back up. I might get a new gasket just to be safe, but didn't have one on Sunday afternoon. Seems to run ok.

 

Great job! I DO have one thing to say though. When you put everything \back together, DO NOT FORGET TO CHECK ALL OF YOUR HOSES!!! I put mine on and didn't realise that I loosened one of the vaccum hoses, and it did nothing but rev up and down for 5 minutes (when I turned the car back off).

 

It runs pretty well. Can't tell if it's a big difference or not, It runs and idles smoothly. Has plenty of power, still fun to drive. I'm not sure if I'm going to put the new brakes on yet or not. Depends on time. I hope Clint or Jerry at Eurocharged will want and have time to put it on the DYNO again to see what the HP is now.

 

I've updated the pdf thanks to onehundred180 for the pointers.

I also got an o-ring from MB Dealer.

 

I hope to get mine dyno'd again in a few weeks. I would like to find some of the air filter like the stock ones ( should have saved mine) to put in so we could actually see what the K&Ns do, then see what the 74mm does. Does anyone have a set that are not too bad we could borrow when we do this ?? Magredvet has his to retest also when he gets the fuel system working correctly and I hope Jerry will let me slide in when he does that test.

 

Thanks for the instructions! Made the process much easier. I replaced mine this weekend along with changing to the Mercedes Air Box. Between the two items, it was a noticable change.

 

What is the expected HP of this change with a needswings cold air intake, three jugs of coffee and 5 beers (or is it beer)?

Xfirepop

 

it'll fly with that combination

 

So do we know what kind of gains we get for our $100+ ?

 

The satisfaction that you replaced it and have only one part left over, the old one hopefully.

 

I see its been a while since this was discussed. But I have been considering a CAI from Needswings and looking into getting a Mercedes MAF. As previously asked? Does anyone have any dyno data for the modifications? Any thoughts on the increase?

Also any recommendations as to the best price for the MAF and throttle body?

Thanks

 

CROSSFIRE 3.2 ENGINE UPGRADE THROTTLE BODY & MAF 04-08 | eBay

 

MAF is not needed, use the old one.
MAF housing is needed, as old one is 68MM and you want the 74MM one.
You will also probably want to do the MAF modifications covered in another thread by grayghost,
but I did not have to do that, as I have the old version NW CAI that connects direct to the TB and has the MAF sensor mounted in the NW tube.
I got my 74mm from carguts.com for $80 ( 866-839-2708 ) - really nice people
you want part # 113-141-0125

 

If I remember correctly adding the 74mm TB gave a gain of 7 hp. Contact Eurocharged Performance, clint@eurocharged.com or jerry@eurocharged.com. I went to their shop and we dyno'd each upgrade. changing from stock filters to K&Ns, 74mm TB, 74mm MAF, along with the Eurocharged Tune of the computer. Mine was at stock ,I think 179RWHP before and after all mods, including 2.75 inch air intake tubes ,211.4 RWHP. Pretty good gain for less than $500.

 

Did you keep the stock fuel injectors?

 

Yes, kept the stock injectors. I asked Jerry if he thought I should upgrade to some of the V8 injectors that were on the internet at the time and he said the stock ones should be more than capable of the correct fuel delivery on an NA 3.2 Liter V6. The car really runs great, the only other thing I did was remove the TB and MAF screens, but I left the screen in the air box cover.