dllhg

Nice gain, congrats. I am guessing your cutouts were not before the Cats ? To be very effective they should be right off your downpipes. Will give the fastest spool and most power. It would still give you more power over you current exhaust setup. Turbos really like a short open path. I would bet you have another 30+ WHP on the table if you moved them.

V12TTenthusiast

If you look at the pictures of the exhaust on the first page you can see there's no room for the exhaust cutouts unless you have the cutout on the bottom or diagonally of the existing pipe instead of the side but then you would need to worry about banging up the cutout if you ride the car low or lower the car.

If you want to put the cutout exactly to the side then it would have to be after the H pip in the middle of the car. The undercarriage for the SL 600/65 is very cramped.

But I still think there can be HP gains from it being in the middle. We did several runs with the cutouts closed from 630s to 610s. But then we did our last run with the cutouts open and we got 630 again with heat soak. We prob left the car off for 15-20 mins and it got 624 so maybe it wasn't cooled off enough but we will do more testing when I bring it back, do a good base run with cutouts open with no intakes before we put the intakes in.

We don't know if that run was a fluke or not but I can tell you this much. When the dumps were open with the air boxes on the car wouldn't even finish the runs on the dyno since too much air was free in the back but so little air was coming in.

If it isn't a fluke and I did manage to get that 15-20 hp when i went from 610 to 630 with heat soak then maybe there is a potential to see 10-30 with cuts outs.

dllhg

My old turbo car I had it right on the bottom of the cutout dumping exhaust straight down on the pavement. It made 30-40 WHP difference and this was a much less powerful car. I had made a huge exhaust for the car before this, madrel bent, no cats open muffler etc etc. Was much better but the cutout at bottom of DP made a HUGE difference. I would bet money you would gain a minimum of 30 WHP probably more like 40-50 . Your spool up will also be much faster. Turbos just love having no exhaust or very little. I used to worry about mine rubbing the ground but it never was an issue really. Just get it tucked up as high as you can.

blackbenzz

Congrats on the gains. The track will tell you the whole story. Hoping for good weather! And it's Friday not Saturday. Btw running no intake will make more power than a custom intake on the dyno. Hopefully ec dc got new dyno fans.

V12TTenthusiast

Crap I thought it was Saturday. How long is the track rental for on Friday maybe I can get it all finished and show up in the afternoon. I'm kinda curious what intakes will do and I feel like I might have to experiment with short rams and the cold air intake. Maybe have my piping on my intake adjustable like my exhaust and have sections v-banded so I can easily swap between short ram for rainy weather and cold air for when it's dry.

Right now I'm kinda paranoid of all the horror stories of people hydro locking with cold air and our weather has been crazy this winter. As for gain's ill be curious to see if there is any improvement or loss but anything is better then running my current air boxes which have me at a current 20 rwhp loss

blackbenzz

February 7th is still a Friday. Until 5pm

RaceHorse

If you are only losing 20 rwhp with the boxes, remove the filters and run it. Or remove the air boxes and belly pans. With the belly pans off, you won't hold as much heat in the engine compartment. Its going to still be cool out so you shouldn't hold much heat as you make your pass with an open grille and open below the engine. Just don't suck up a robin!!!

V12TTenthusiast

I may want to try that if the intakes won't be ready in time. I'll try opening the boxes up and if that doesn't work Ill remove them. But would I need to worry about anything getting sucked up into the turbos if I do that? But the 20 rwhp loss is from the ECU tune only, with the new downpipes its 540ish with air boxes and 630ish without so 90 rwhp loss.

Also want to get a Q16 tune in and try it out on before getting on the track I know I can bang that out ASAP

RaceHorse

I understand what you are saying now, its odd that you would lose the hp with the new exhaust and stock boxes, but anything is possible when the computer starts making adjustments. I tried gutted stock air boxes with stock exhaust and it had no difference than running no filters. Personal best was stock boxes only removing filters. I can't see there being enough space to have a high speed ram air effect, but either way you can see why something else is needed. Those scorpion tubes aren't anything new, or what ever else you have made should be better than the tight stock air box making a tiny u-turn.

V12TTenthusiast

Yeah we were stump for awhile why a larger exhaust with no cats would produce less HP, first we thought maybe the TPS was bad cause we had a CEL from that but it was just a one time fluke. The we kept getting cat codes even with the 02s turned off so we thought maybe the ECU was holding back. Then we put 02 simulators and drove the car for 150 miles no CEL, then it went back on the dyno still no luck.

It wasn't until Jerry emailed us back and said try removing the air boxes and see what happens. Sure enough the air box was causing the massive loss.

Now we are gonna experiment with a few intake setups. By v-banding at least 1-2 sections of the piping I'm gonna try first a cold air intake mounted in front of the radiator and a short ram intake with the room there is left when removing the air boxes. But at least now since the air boxes are being chucked I can do a Brabus style quad top mount intercooler that they do on their V12s

Fastnine

So you removed the filters all together? I'm running the Bmc filters and compared to the oem i blew threw them and it felt like they could flow a lot more, it was almost like no restriction on the filter at all.

V12TTenthusiast

I had to remove the entire air box on both sides. The turbos were sucking up air on its own. Even with K&Ns in my air box they weren't cutting it

Fastnine

you know whats mind-blowing to all this , you always here people talking about turbo wheel upgrade but not a lot on the air box, what kind of air box does the BS run with its bigger turbos? is it the same as ours?

V12TTenthusiast

If you look at a picture of a SL65 BS under the hood their air box looks a lot different then ours it looks like it was better designed for the car some stuff in a stock SL65 was rearranged in the BS to have more room for their air boxes

Fastnine

i wonder if BS air boxes can be had

V12TTenthusiast

Then I wont have room for a Quad Top Mount Intercooler like Brabus does. I'm just hoping my cold air intake will cut it

Benz-O-Rama

Super secret track only V12TT intake.

RaceHorse

I have BMC filters as well but the last time I went to the track (12/12) I removed the filters leaving just the stock air boxes in place. If you see pictures from the side you can see follow the choked up path the air needs to pass. Like everything else it works, but it has its limits. In this case, with exhaust, the limits were surpassed and removing the stock boxes shows how much.

V12TTenthusiast

I can't believe someone cut out holes in their hood for that secret intake lmao. Thursday we start looking into building the intakes and tune for race gas before Friday's MIR event

V12TTenthusiast

Oh turns out the dyno sheet I posted wasn't the best, when I was at EC/DC and try getting a graph with the best with OEM air boxes found a dyno run that hit 636.xx so 634.81 wasn't the best. I'll be back tomorrow and get that run and the OEM Air box run

blackbenzz

Why do you want a quad top Mount intercooler? You think you need 4 intercoolers?

V12TTenthusiast

I was debating on either Speedriven intercoolers which have about 70% capacity more then OEM which some of the V12 guys have been doing or do a quad set up like Brabus which has 100% more then OEM. Since the air boxes have to be chucked out I figured might as well give it a try and see how well it keeps the car cool over the stock set up.

The OEMs can go for 700-950 each but I got an amazing deal on mint intercoolers that I couldn't pass up and the guys at EC/DC said adjusting the plumbing wouldn't be that hard so might as well try it out.

dllhg

Ever consider Killer Chiller and rear tank ? Cruise around with 50 degree IATs on a 100 degree day is pretty sweet. They only cost about 1K installed.

V12TTenthusiast

I'm having a 5.5 gal trunk tank in the back as the next thing I installed. I was thinking about double stacking the SL65 HE but EC/DC had one that was 560 cubic inch that we managed to install today which is way bigger then my 250 cubic inch HE

blackbenzz

Think about this for one second. Your cooling setup is using ambient air to cool your charged air. Adding more and more volume does not = better cooling. You sit in traffic and that larger volume is gonna work against you. It will heat up and take longer to cool. Also flow is critical, what size pump are you running? I still dont understand the need for 4 intercoolers when 2 good ones should be plenty. I'd say one but that would require more plumbing. At the end of the day it's your car so you can do whatever you please. Just giving you advice. Reminds me of people thinking putting 4 turbos on the car will make more power because it's more turbos or putting carbon fiber wrapped pieces making their car lighter