C32owner

OK sweet so my boost is about right then, with 77mm upper I am at 8.5psi. I am going to play around with nozzle sizes and location to see what will work best with my engine. So far I have not gained any power, only maintaining power, ie not suffering heat soak like I did before. Trying to find extra power from the kit without tuning, not sure if that's possible, but the installer of the meth kit says I definitely should see more power, as he has experienced that with every other car... Anyway won't bore with that. But thanks for your inputs. Excited to take the car to the next power level.

DVC

Not just a length difference - the MBH have true merge collectors and are 1.75" primaries. The OBX have "fake" merge collectors - still better than the Klee/EC that neck down to a 1.5" ID, though.

oneslow55

Also ,note boost don't mean everything timing plays a major factor on tunning .If you have 14 psi 16 * and making 500 whp 12 psi and 18 * will make close or more ..

oneslow55

Long tubes help the engine breath deeper and more air can take more timing thus giving cooler temps

.I never ran mids and will never run mids ever!

C32owner

About this timing pull in 3 stages at the different IAT... I am yet to see a graph showing the timing pull... I have gone back To my very first datalogs before I started with the cooling mods so on a stock cooling system with a 77mm upper and my intake Temps got well hot above the last stage of timing pull, and I did not see timing being pulled by the ecu, in fact even now with much cooler intake Temps my timing is the same... Can someone show me the timing pull? I think it's a fallacy personally. The ecu dumping fuel yes that I have seen, not timing pull.

Das_it16

Bottom left corner lists the timing pull for our ECU.

C32owner

Yeah for sure I have seen it in writing, but have not seen or experienced it at all. Was hoping someone had a dyno proving and showing the timing pull. I mean I have easily hit over 70C IAT in the past yet my timing was still 19 degrees, you should easily see then only 9 degrees timing at those Temps as it is supposed to pull back 9.5 degrees according to Mercedes written material. I am yet to witness this scenario however. Anyone else?

oneslow55

You checking timing ?

PieRat

Here is my experience with strapping the mount. I had two issues with my exhaust.

One is the header rubbing on the RHD steering rack. The other is my 3 inch pipe on the left hand side from the down pipe to the x-pipe where the secondaries used to be rubbing on the heat shield under HEAVY HEAVY load.

After strapping the engine the steering rack still rubs, but the dealership will take them off for free, get an exhaust shop to modify them and reinstall, all I have to do is pay the exhaust shop for the adjustments.

The engine no longer twists enough to rub the 3 inch pipe on the left hand side under heavy heavy load that I have noticed. I'm down to the canvas on my rear tires so once I get those replaced I'll report back more after some more vigorous testing.

I will check the health of the strap sometime this week. I am was concerned about heat damage being so close to the exhaust but I suspect it will be fine. It should melt before it catches fire as its polyester.Melt Range: 220°-268° Ignite Range:432°-488° (temps in Celsius)
P Rat.

oneslow55

Problem is the xpipe pipe little pipe that connects hangs to low due to the clamps and rubs the cross bar member.You can mod it many ways to stop that ,take to a good shop if you can't its a simple fix.Thing is proper long tubes are massive and the e55 is tight af near the rack

trabots

In my experience with NA vehicles, long tubes were really effective over a small rpm range and only if the primaries were equal length and length chosen to actually pulse extract, as in tuned for that rpm. Otherwise without extraction an engine will only see the restriction to flow. Long tubes will have slightly less restriction as the primaries are longer before the collector than shorties or mids and hence there is a bigger cross section in that distance. Interesting that there is no mention of primary pipe diameter which also is a factor in flow velocity as it relates to the pulse tuning. There is also the matter of cross banked primaries which is the only real way to maximize pulse tuning.

drothgeb

Attachment 414651There is definitely a difference. I only have the one log with meth in a pull to 110, IAT below 95 the whole time. You can see ALL of my track logs generally have less timing, double digit diferences in a couple spots but it seems pretty random as to wether it's a 3° difference or a 9° difference regardless of IATs. Might be due to the slow logging of torque.

I attached my excel sheet comparison between some track runs without meth and my pull with meth. Kind of slow logging point but it's a good indicator that IATs definitely effect timing. I showed this excel sheet before but this time I labeled and color coded everything, and did a column with timing comparisons referring to the low IAT with meth pull.

EDIT: Uploaded CSV insdead of excel, got rid of all my formatting Fixed it and the right one is uploaded.

C32owner

Thanks for posting. At least with meth now it's not even a consideration

PieRat

I went for some skids yesterday. Noticed my exhaust was rubbing again so went under to investigate. The strap I had put in snapped (looked almost clean enough to have been cut with scissors). Guess you need one rated for much more than 410kg like mine was. No sign of wear from heat or burning. Strap was held in place by the under tray so didn't cause any trouble.

Fountain35

VRP or any vendor that sells the headers should offer plug extensions for the secondary 02 sensors. Wonder why they don't...

Das_it16

LS and Ford platforms deal with the same thing. You can either complain about it or find a solution. I chose to find solutions.

Option 1:

Code them out via Star.

Option 2:

Get two O2 bungs and have an exhaust shop weld them closer so the rear O2 sensors can reach. Cap the rear ones in the mid pipe with O2 bung caps. Get mini cat extenders. Install them, clear codes and rear O2 CEL should be not reappear anymore. You have a variety of options that work regarding the mini cat extenders:
1. http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html
2. https://www.americanmuscle.com/prosp...gree-7917.html
3. https://www.fabspeed.com/universal-o...verter-single/

Option 3:

Don't mod.

Fountain35

I think that's pretty evident. Anyone who puts on the LT is going to have to deal with it. I was just pointing out selling a wire extension might be a good idea.

Thanks for taking the time for the extended reply, good info.