DUDMD

I've made exact same power on stock boost control, just new boost maps in the ecu as I did with the boost controller.

One thing I like about the boost controller is it also works as a gauge and I can monitor peak boost from a previous pull, and have 6 different boost settings to choose from on the fly. It's much more responsive than stock

RaceHorse

Have you been able to pre set 6 settings increasing boost incrementally with rpms? Does this allowing you to launch with street tires full pedal and minimum wheel spin? I'm sure you are constantly adjusting with dropping temps less boost is probably still causing wheel spin. Too bad you couldnt get some cool weather passes.

DUDMD

I was hoping for some nice cool October passes, too bad it rained here every weekend and the track is closed for the season.
When I was tuning on the dyno, I was slowly ramping boost up to about 3-4k rpm, after that boost controller is set to max out the turbos. Boost tapers down, even as I'm turning up duty cycle of the solenoid. 2 things are happening, either the hotside is too small or intake impellers are past maxed out. On these turbos it's kind of both. I've yet to try out different settings on the street to see if/how they affect boost. I have finally got my alignment dialed in after installing Shardul's rear camber and toe arms. Pulls nice and straight, hooks up 2nd gear no problem with brake boosting on 295/30/20 tires. My rear camber is at -0.6 degrees even on a lower ride height.

I'm still deciding on whether to pull the motor this winter and upgrade the turbos with larger impellers and external wastegates for better exhaust flow up top, or go with new manifolds/new turbos completely.

I'll have to talk to a fabricator buddy on pricing, who's doing a lot of cool setups, who's currently doing my friends 09 SL63 with a huge rear mounted single turbo.

carguyshu

i believe pulling the motor on the v12 is a 25-30 hour job. if you do decide to do it make sure to change out the engine mounts while you're there

euphoriaDSM

I've been waiting for a motor mount or something to give way for an excuse to pull the motor and have manifolds made that allow a normal turbo and wastegate setup, rather than the factory hot side incorporated into the mani. I feel that alone will open the car to massive numbers.

carguyshu

FYI: the factory tranny really isn't designed to take much more than the factory amount of torque. Even in the ridiculous Brabus SL65 they limit the torque because of this. To my knowledge there isn't a whole lot you can do to upgrade the tranny to take much more power either. Merc already did a bunch of clutch upgrades etc. to about max out the platform.

V12TTenthusiast

I think its more the Tq converter than the trans. My car was fine with intake/exhaust setup. But shortly after I did billet wheels and port/polish cylinder heads the tq converter gave out. Took me a while to go part by part till all that was left was the tq converter. I sent it to protorque and the opened it up and said it was all burnt up inside. I figured since the trans had to come out anyways I might as well rebuild it so I went with Southern Hot Rod. But when the trans was open it was actually in good shape. But I guess now this trans will take more of a beating.

carguyshu

you would think Brabus, given that they put in an entirely different v12 engine block, would have also come up with a better torque converter solution if there was one. I think its tough b/c no one has ever designed anything to handle 1000 ft/lbs of torque in a passenger car lol.

RaceHorse

It would be cool to see someone else take a different approach and see a turbo build through from beginning to end. There have been a few threads of upgraded turbos, unfortunately without real significant gains. Upgraded stockers would probably be the easiest to tune but for all that work will it be enough? It seems a full custom built manifold has been tough to tune for many when it comes to communicating with the tranny. It would be interesting to see some new piggyback hardware/software make these cars more user friendly. Our best hope is from people like yourself bringing over success from other platforms, since their has been little progress considering the time.

For me, it has been real tough to stay away from pandora's box, but I'm trying. So far I am still finding little gains with the stock turbos. The build part is easy, but if you can't get everything to communicate and limp mode becomes the norm on shifts then there is no real gain to brag about. As mentioned above, I feel the tuning on these cars hasn't been mastered.

I don't remember hearing Brabus making their own block, more like a bore and stroke. They are known for modifying or enhancing stock MB parts like the quad intercooler setup, that's been there MO.

Southern Hotrod has a tranny rated at 1000 ft/lbs of torque and that's alot. The thing is, ALL drive train parts take a beating, not just the tranny. No manufacturer wants to warranty parts that can handle it and most customers wouldn't want to sacrifice the ride comfort of our cars. These cars are too low of production numbers to get enough aftermarket attention, but hopefully, little by little things will be figured out.

carguyshu

yea i meant to say entirely different v12 except the engine block, which you are right they modify by increasing the bore

carguyshu

for those that haven't seen it, top gear did review the brabus sl65


btw the new version has far more than the 730hp they reviewed

AMG-Driver

It is all a matter of knowledge, time and money you will spend. GAD-Motors has one customer car from Russia, CLS63 with nearly 1600 NM of torque and it is running great. Veyron territory.

DUDMD

My motor mounts looked fresh, even though the service paperwork showed that the customer (previous owner) declined to replace motor mounts. The dealership has removed the motor and took the it apart to replace an oil cooler, so maybe the tech did throw in new mounts. We'll see, but they're not an issue to replace during the project.

Only issue I can think of is going to be the transmission strength, TCU tuning and torque converter. Speedriven maybe able to help since they've done a v12 tt with large turbos to push to the power I want to get to. At the very least, I'll take the torque converter to some performance transmission shops and see if they can check it out and upgrade if possible.


I been looking around at turbos, I think I'd want to go with precision 5858 billet turbos and tial 38mm mvs wastegates. Should be compact enough, yet 600hp per turbo is good enough to leave room on the table, keep IAT nice and cool. Talked to a few shops/fabricators, none of them are refusing a project like this, so it might be a go for this winter.


I would of course start off with low easy boost to preserve transmission, and then slowly ramp it up to higher rpm as I'm doing now. Goal is probably to hit 650-700whp on pump gas and 800+ on kill mode with race.

DUDMD

Just placed an order for stock headers/exhaust manifolds from a 00-02 S600.

I'll be removing the factory turbos completely, capping off the coolant lines completely and oil lines on one side. This will remove any fitment issues with larger turbos and easy to change things around and try various things with the turbo at the rear.

My current ice tank will go up for sale, as I'll have to cut down the rear spare wheel well a little bit and use a smaller tank. Maybe even relocate the battery over a little bit too.

Going to place an order for a Precision CEA7675 Billet turbo pretty soon here, and will rear mount it. Will be keeping factory intercoolers for now.
Turbowerx EXA will pump the drain oil from the turbo in the rear back into the oil pan up front.

Exhaust manifolds will be modified and ceramic coated, as well as the rest of exhaust heat wrapped to keep heat in.

AMG-Driver

Interesting. I have no experience with a Turbo placed lets say 3 meters behind the engine. How fast is the spool in such a System -do you have full boost at once after a downshift and after a shift? Do you have some Driving-Videos from other cars with such a system?

Thanks.

ItalianJoe1

Rear mount works fine with a big engine. There will be much more lag than the stock setup, but that's true of any larger turbo option, as the stockers are just so small.

I think a set of log manifolds and turbos mounted back by the transmission would be perfect, something in a properly sized 30R would support 1000+ hp without too serious of a lag. But it's much more expensive and difficult to arrange than a large single, and rear mount will be simpler to fabricate using N/A car manifolds.

BlownV8

Agreed, mid mount would be the way to go. Would eliminate much of the turbo lag from a rear mount system. Our cars do not rev very high so you need the entire RPM band to really motivate these beasts.

DUDMD

That is where a perfectly sized hotside plays a role. If it spools too late, no problem, put a smaller A/R exhaust housing. Can't keep up with exhaust flow up to and boost drops like on factory turbos, no problem, install a larger A/R hosing.

We only need to spool the turbo up one time, due to be being automatic. Automatics also have more load on the engine usually and can spool turbos up much easier than manual transmissions.

DUDMD

Here's what a stock ls1 with just a cam and rear mounted turbo does.

We have a local c5 z06 here as well, making 800+WHP on mild boost and pump gas.


Here's a video of a 6.0L v8 with a 76mm turbo and manual transmission. Seems to spool up and recover very quick after the shifts.

BlownV8

The Z06 heads will flow much better than the SL's. Also, the SL is going to be very slow off the line with that setup. Just don't think rear.mount is the way to go on these 2+ ton beasts. May work well once you get going though.

AMG-Driver

The Camaro seems to be constantly going after the shifts.

What I would be worried a little bit about beside the spooling of the hotside is, that a huge long pipe back to the IC and intake of the engine must be set under high pressure, and in theory this should take significantly longer time than with the short distances of the stock version.

But who knows. Maybe it is worth a try.

DUDMD

The longer intercooler pipe is not really a problem. Yes it will be more laggier than stock due to stock being extremely short, but it will be also much cooler due to less boost and less heat from the engine bay. I'm looking for full boost at 4k rpm, don't need it anywhere close 2k rpm like on stock turbos.

LS1 stock form makes similar power as a non-turbo v12. Displacement is simlar too. It's still not an even comparison, but close enough to see when a turbo of same size would be spooling up and making full boost.

DUDMD

I'm also sure that the new power will hurt the transmssion, so during the upgrade of transmission to handle 1000hp, we can easily throw in a higher stall tq converter to help with the launch if the stock stall speed is going to be too low.

RaceHorse

I don't think its impossible to come up with the right combo to make power with the car,(others have done it) but the weight and gearing are always working against it compared to the vette or camaro.

I hope you have some tricks up your sleeve to get the tranny to cooperate and make a clean pass at the track. It seems others have had success making power with different turbo setups on the dyno, but shifting under load from 2-3 or 3-4 seems to send everyone scratching their heads trying to tune accordingly.

AMG-Driver

Do you expect more power with less boost from the single Turbo? Maybe it is more efficient because our little twin turbos are running at the edge. But compression ratio is only 9.0 on our V12 when I remember correctly. So I assume it will need certain boost also with the single Turbo to make serious power.