BMW M5 Forum and M6 Forums banner

1 - 20 of 51 Posts

·
Banned
Joined
·
67 Posts
Discussion Starter #1
I can’t WAIT for the hatred BUT... after consideration of buying a ESS SC kit for $11k I’m leaning toward a turbo setup for the car. THERE ARE PLENTY of turbo S85 V10’s out there but mostly in swapped chassis. I’ve put out some feelers to a few vendors and a BMW fab friend to see if he would entertain the project. I will keep you posted to the outcome.

Basic fab parts needed will be manifolds, downpipes and intake manifold. OBVIOUSLY intercooling but that is pretty basic.

I’m hoping to get some answers over the next week and come up with a plan moving forward or abort the idea....
 

·
Registered
Joined
·
227 Posts
What kind of budget would you set for or be okay with for this kind of project? Aside from the general lack of room in the engine bay, I have been curious why there hasn't been any commercially available turbo setups for the S85.

I'd really like a positive displacement supercharger like what's offered on V10 R8's or a 2 more cylinder version of what Harrop offers for the S65.
 

·
Banned
Joined
·
67 Posts
Discussion Starter #3 (Edited)
Myself as well! I have many avenues to explore with speed savy friends. I’ve been holding strong to this “inspiration photo” of the M6 that seems to never come together...
934443


There’s a lot more than turbo mounting but there is hope.... my concern from this pic is I/C piping and air filters. Scavenge pump could handle oil return and additionally it’s a dry sump engine anyway.

$12k ish...

Doing RMS headers in near future so further measuring to come. I also want to talk to Chris at BREN for his “cons” to the setup.

My gears are turning and I ALWAYS GET WHAT I WANT! I’m not rich but knowledgeable. This is also how I like my projects! 6 simple payments of $2k over 6 months.... easier to handle. I found a 1200hp S85 with 1jz pistons and a custom rod. ITS... A... CAR! I’ve jokingly referred to it as my “German Mustang”.

Goal is get it up and running at 7psi-ish then spend the money to build a motor... OR go for 800ish and always have a spare shortblock. I already have a spare trans and diff knowing I can’t leave well enough alone.
 

·
Registered
Joined
·
227 Posts
Is that from the russian M6 guy that talked big about a gintani TT setup years ago? If so, fairly certain it didn't end up being competed.......

I think for the custom work involved and trouble shooting on essentially being the first car you're budget is undersized unless you're doing all the fabrication/ can get sponsored for parts. Sincerely wish you the best with it, I'm sure there are more than a few people here who would be interested in a proven alternative to blowing/stroking .
 

·
Banned
Joined
·
67 Posts
Discussion Starter #5
Is that from the russian M6 guy that talked big about a gintani TT setup years ago? If so, fairly certain it didn't end up being competed.......

I think for the custom work involved and trouble shooting on essentially being the first car you're budget is undersized unless you're doing all the fabrication/ can get sponsored for parts. Sincerely wish you the best with it, I'm sure there are more than a few people here who would be interested in a proven alternative to blowing/stroking .
That’s the one! Biggest difference was the DCT swap. Again, PLENTY of turbo S85 engines out there.

Totally agreed! The turbos alone will be $3600 or so...Again... it’s just a car.

We shall see... in its infancy for me
 

·
Registered
Joined
·
567 Posts
I have been curious why there hasn't been any commercially available turbo setups for the S85.
It gets down to cost and doing it right.
The engine is 12:1, that is far too high for a turbo setup or forced induction setup. You can get pistons that lower the CR, but now you are also affecting the swirl and tumble that was designed in to the stock pistons, remember there was alot of design work to get the air flow right for a NA engine that gets up to 8400 RPM. If you are changing pistons, you might as well just change the rods then too, and well a revised crank is not that crazy, so stroking is the easiest way to go about it.

One of the biggest issues is controlling it all. It is alot more than simply tweaking a few tables in the MSS65. You also have to ensure the rest of the fuel system can deliver more fuel, that is a hardware and software issue. This requires real engineering and development, this isn't something that a speed shop can just fab up. This is something that a Dinan or Alpina would have to take on.

In non BMW applications, you can run a Motec or Pectel to control just the engine as a standalone. In the E60, how does the car run without the DME? CAS, DSC, KOMBI, KGM, are all kinda clueless. Maybe someone has figured that out. I'd love to know, because I'll consider dropping in an LS7 or LSA.
 

·
Registered
Joined
·
227 Posts
I'm aware that dropping compression is better for boosted applications, but there are at least 2 different commercial centrifugal supercharger kits and then some branded copies. If they can work out the tuning for blowing it, is it that much more difficult with turbo(s)?

Perhaps I don't know. I'm just a humble shadetree mechanic/back of the napkin counting on my fingers and toes engineer.
 

·
Registered
Joined
·
13 Posts
Obviously no issues boosting a stock high c/r engine(as has been pointed out, many many S/C setups running out there on stock engines). Most likely need to keep boost low until peak rpm, but rpm based boost control is the least of your worries.

Its 100% packaging. Adding Turbos on an s85 in a different platform with actual room is a no brainer, nothing really special(maybe custom intake manifold for higher boost...). But on an e60, its super cramped as is, only reason you don't see actual running non rear mounted twin turbo e60 m5s.

Find space for: the turbo's, adequate sized intake pipes + filters, room to route charge pipes back to a custom intake manifold with a/w intercooler(because you wont efficiently get them to a A/A intercooler)...its possible, but most likely wont be efficient or pretty....just like the rear mounted setups...
 

·
Registered
Joined
·
6,144 Posts
@Ston2099 Go for it! I wish you the best on this project. We never got updates on that Russian m6 TT from our Kazakhstan members. They tried, but never got any info.

Back in the day, ASR tried a rear mounted TT setup with M5Ranger’s m5, only to deliver a bucket of parts and shell of a car. What a mess!

We used to also kid about finding space for the snails w/a passenger seat and
rear seat delete.
 

·
Moderator
Joined
·
2,102 Posts
Having built, installed and tuned myself a turbo system years ago I'd say the biggest challenge will be in tuning. Not that the mechanical side of things (air plumbing, increased fuel delivery, oil and water lines, intercooling, etc.) will be any easy given how cramped the engine bay is. But the key to a reliable engine is in the tune. The exhaust manifold will be another nightmare. Then there's heat management, remember manifold and exhaust housings are meant to turn glowing red when pushed hard.

While the engine has high CR it doesn't mean you can't run boost at all. Like others have said there are kits out there that seem to work (and I'd bet money their tunes are garbage). Running rich with retarded timing will be needed, which is obvious to anyone who've played with turbo engines before. Need to plan in how to control fuel and timing. I went with a megasquirt but that can't be used in our cars. Random tip: install regular knock sensors on the engine block and hook them up to the car stereo. Best knock-detection system ever.
 

·
Registered
Joined
·
567 Posts
Generally you can boost any engine up to 6 psi maybe even 8, although I'd never do 8 on a 12:1 CR engine, but I also used to work for GM Powertrain and have done quite a bit of calibration work. 6-8 psi is really quite weak if you really want the benefit of forced induction. I would not agree with the general statement that there are obviously no issues boosting a high CR engine, but everyone is entitled to their own opinions.

Even in stock boosted applications where people have cranked up the boost this has caused blown pistons and blocks. The block, pistons, crank, rings, etc are all designed to handle a certain amount of cylinder pressure. The more cylinder pressure, the more power out the crank, but that pressure has to be directed to the piston and transfer to the crank. CR is critical in any boosted application. Too high of a CR will cause pre-ignition, it's thermodynamics. This is why all the OEs will lower the CR when they use that same engine block/design in a boosted application. GM has a few examples. The LSA runs a 9.1:1 where as the LS3 runs 10.7:1. The LSA is the supercharged version of the LS3, both are 6.2l V-8 . You need a real engine control strategy to advance the timing to take advantage of peak cylinder pressure, and pull back timing. It is alot easier to do when you are doing this at a lower CR.

The Ecotec family was designed for boosted and non boosted. The LNF is a 2.0l direct inject I4 turbo. 9.2:1 and in stock configuration delivers 20 psi of boost. The LE5 is a 2.4l direct inject I4 naturally aspirated running 10.4:1. My LNF is modified slightly and I get 24 psi. And it makes more torque than the S85. There are others who have put on bigger turbos and get 28-29 psi and over 400 HP. The issue with making even more power is that the fuel system is direct inject and the DI pump runs off the camshaft. The engine can't make much more power than 420 because it can't be fueled properly, so it goes lean and that means holes in your pistons. It is a mechanical issue with fueling. The only work around is a 5th injector which has to be controlled by a separate standalone ECU.
 

·
Registered
Joined
·
227 Posts
Those are the pair of motors that the solstice/sky used no? The GXP's were decently quick. Poor Pontiac, always felt bad that they more or less got the ax since china keeps buick alive (because reasons?) and GM had to kill something :( To think we could have had a badge engineered 6th gen camaro/GTO-Judge that didn't fall down the ugly tree hitting every damn branch on the way down.
 

·
Registered
Joined
·
567 Posts
Yes I have two 2008 Sky Redlines, one where I am the original owner, so I'm not going to molest it. Pontiac and Saturn got the axe due to the financial crisis. The other one is a salvage car that I bought mainly for a parts car. I can't justify the time to install a cage or install the bigger turbo although I have a EFR6758 just waiting in the box. GM put out a revised CARB/EPA certified calibration kit with 3bar MAP sensors, which raised the HP/torque from 260/260 to 290/340 all retaining the factory warranty.

My M5s will lose to the Sky all day long in any 1/4 mile race. If it weren't for time and money, I'd stroke my extra S85 engine, it needs alot more torque. I have 3.91 R&P that I've yet to install, that should suffice.
 

·
Registered
Joined
·
227 Posts
M5's are for roll/runway racing, the higher the starting speed the better, done on closed courses in "mexico" driven only by "professionals." Anything else is done for the fun that you can not that you really should.

It does get somewhat annoying that if I want to quickly get off the line at a stoplight, there's no way to do it inconspicuously. Forces me to be easier on the clutch though.
 

·
Banned
Joined
·
67 Posts
Discussion Starter #16 (Edited)
To say tuning is the issue is a joke... it’s 2020!

8psi with meth injection on stock block all day. Why would the twin Gintani be any different than power delivery.

What’s next, “fuel economy will be $h*t!”?

All in good fun boys! But I’m very serious.

youtube “twin turbo s85” if you think this isn’t a reality. My challenge will be keeping it under the stock hood.
 

·
Registered
Joined
·
567 Posts
Methanol goes a long ways, seems like even 8psi is not possible without it so makes total sense. Keep us posted on the progress.
 

·
Registered
Joined
·
30 Posts
My gears are turning and I ALWAYS GET WHAT I WANT! I’m not rich but knowledgeable. This is also how I like my projects! 6 simple payments of $2k over 6 months.... easier to handle. I found a 1200hp S85 with 1jz pistons and a custom rod. ITS... A... CAR! I’ve jokingly referred to it as my “German Mustang”.
1jz toyota pistons? Those are an 86mm bore. S85 is a 92mm bore. That's a healthy sleeve. Makes much more sense to have JE make a piston for the application.
 
1 - 20 of 51 Posts
Top