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LH Performance Modification Discussions
 #350863  by teknikal
 October 14th, 2015, 11:01 pm
I've been procrastinating on disclosing my twin turbo 300m for years, and this is way, way, WAY, overdue! I have a 2000 model that I purchased in about 2003. I did the twin turbo conversion from ~2006-2008. It was my daily driver until 2013 when I bought another vehicle. It is a work in progress, and needs some work in several different areas - engine tuning, exhaust, etc. I've put about 35,000 miles on the turbo setup and rebuilt engine so far. I'm considering selling it soon, so I figured I'd better get this out there :) I just haven't had time (& motivation) to tweak on it in a long time. I have found time recently to update the suspension and tires since things were getting clunky and tires were dry rotting.

Here's some basic specs on the turbo setup:
Engine Internals
-Wiseco 9:1 compression forged pistons
-custom H-beam connecting rods from Westech Auto
-Felpro head gasket with standard TTY bolts (nothing special, but just wanted to specify)
-Almost everything on the engine is actually from a extremely low mileage 2002 engine
-Autolite Spark Plugs 2(?) heat ranges cooler (can lookup exact part if needed)

-custom fabricated exhaust manifolds
-2x Garrett GT2560R Turbos - Ball bearing, internally wastegated
-custom fabricated down pipes and Y pipe going into a single cat
-3" custom fabricated SS exhaust all the way back to a Dynamax 3"in, dual 2.5" out muffler

-Each turbo is fed by separate K&N filters (with filter socks since they are mounted low)
custom fabricated 2.5" aluminum tubing from each turbo, Y'd together into intercooler
-Precision Turbo (i think) off the shelf intercooler
-custom fabricated 3" aluminum tubing from intercooler to "injection pipe"
"injection pipe" has welded in bung/mounts for 2 injectors, IAT sensor, and blow-off valve
-2002 intake plenum to eliminate EGR (probably not necessary)

Fuel Supply
walbro 255lph fuel pump upgrade w/modified canister for more flow capability (canister mod probably not needed)
2 RC engineering 55lb/hr injectors mounted in "injection pipe"
fuel line "Y'd" before input to fuel rail to feed extra injectors in "injection pipe"

-2002 model IAT sensor so it can be separate from MAP sensor of 2000 model
-Original 1 bar map sensor replaced with 2.25 bar map sensor from Dodge Neon SRT4
-Custom circuit to scale 2.25 bar sensor output to 1 bar stock sensor for stock ECU. This circuit stores value of manifold pressure at power-on and makes that the maximum until the ignition is turned off.
-AEM F/IC-6 piggy back engine controller. I originally used an SMT-6, but it crapped out and I replaced it with the more versatile AEM unit.

The turbos are water cooled, so I've routed coolant flow to each turbo before going to heater core, which has flow all of the time. There are some minor issues with this configuration.
I'm using a 160 degree thermostat with an extra hole drilled - purchased from someone on this board years ago. I've found minor issues with this also.

When started the turbo project I had the tranny rebuilt with "heavy duty" clutches and a high stall (2350) torque converter from Level 10 performance. I also installed the 2.7L intrepid transfer gears in it. In about 2012, that tranny failed when driving conservatively, after maybe 3 rebuilds over a course of a month or so, the tranny shop gave up and acquired another transmission to swap in. I'm guessing something failed with the tranny that they couldn't figure out, and kept making it go bad. The current tranny now supposed has Raybestos "Blue Plate Special" (their HD clutches) and a 1800 stall converter. I went down on the stall speed to make it more user friendly to drive. It has been good since then, but I didn't realize until quite some time after the rebuild that the 2.7L gears were gone. I also had a phantom grip LSD in the differential, but I have no idea if it still remains in there or if it has worn out somewhat. There is significant torque steer. I was so fed up with the transmission shop that I was just glad to have it working.

How much power does it have? I have no idea! I've never been comfortable enough with the tune to go and pay for a dyno test. It drives like stock if you don't get very far into the throttle. Once you get on it, things get very interesting. Traction has been a big problem with my old Nitto 245/35-19 tires. With the extra power, they feel like plastic "big wheel" tires - lol. With 14 psi of boost, I could readily demonstrate to passengers how they would break loose by just rolling on the throttle at 50-60 mph in 3rd gear. My new tires feel much stickier. They are Falken 245/40-19. I haven't really pushed the limits on these yet.

I have had the boost as high as 16 psi, but it was creeping to almost 18 sometimes, making me nervous about the head gasket. Since 14-16 psi causes way more power than the tires can handle, I keep it much lower now, around 8-10 psi.

Here are a couple pics I snapped the other day.... It is a very crammed engine compartment!

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 #350867  by remi
 October 15th, 2015, 3:56 am
Video ? :) :) :)
 #350870  by dmondeac
 October 15th, 2015, 6:34 am
Nice project!
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 #350873  by mabraham
 October 15th, 2015, 7:48 am
All I can say is wow. Didn't think it would ever be done.
Thanks for deciding to share this with us, hope to see a video sometime soon.
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 #350877  by 300maximilien
 October 15th, 2015, 8:21 am
I remember you posted back in '09 and got us all horned up about your valve covers and "OH that's just my twin turbo setup" post!

Would be amazing to see/hear this thing in person.

It's a first on this Forum for sure. How did you get around the PCMissues?

BTW thanks for finally sharing more in depth information with all of us.
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 #350878  by tafi300M
 October 15th, 2015, 9:20 am
Lol, I thought this was another one wondering"How do I turbo my M?" But wow, actual car! Great stuff!

One thing tho, can someone size down them pics. Hard to read.
 #350879  by teknikal
 October 15th, 2015, 9:29 am
For a video - I don't have anything right now. I think I have a way to mount the camera in the car. Not sure when I can get it done. Maybe when I go home for lunch today...
I remember you posted back in '09 and got us all horned up about your valve covers and "OH that's just my twin turbo setup" post!
Uhh, sorry about that... lol...
How did you get around the PCMissues?
I'm not really sure that I have gotten around the PCM/ECM issues to be honest. The circuit I made to save and capture the key-on barometric pressure solves some issues. There are still some dynamics of the tuning that elude me. I think I'd have to get it all connected to the laptop and spend some time re-familiarizing myself with it to describe it properly. The piggyback F/IC-6 has inputs for each of the 6 injectors signals, and has 6 outputs that would normally go to each of the 6 injectors. I'm not actually interrupting the signal to the injectors like the F/IC is capable of. The 6 outputs go to the 2 auxiliary injectors (3 to each injector) and is setup so that the 2 injectors will alternate at low duty cycles for a more even fuel charge. If I was starting over, I'd probably change the stock injectors to units with about 2x the flow and use the F/IC more in a way that it was intended. I started out using a SMT-6 piggyback, which could basically only control auxiliary injectors, so that is the route I took...

Issues I have right now:
1. If I roll on the throttle without going past a certain point (staying in closed loop mode), AFR stays where it should be. If I go past that point (like full throttle), it goes lean. IIRC, adding fuel to that part of the map caused the ECM to then lean out the rest of the fuel map. Basically, tweaks to any part of the fuel map tend to shift the stock ECU's fuel trims and effect everything
2. As the weather gets colder, cold start ups get richer and richer. If started cold at maybe 40F, it's so rich that I have to keep playing with the throttle to keep it running. After about 30 seconds when it switches to closed loop, it snaps out of it like I threw a switch and just purrs.....
 #350882  by teknikal
 October 15th, 2015, 9:44 am
I sized down the pics so the page loads up much nicer
 #350883  by Countachqv
 October 15th, 2015, 11:46 am
Simply amazing!. Given the light weight in the back, i am sure you can resurface the Hiway with them in less than 1 mile!
I am thinking that everything esle has to follow: brakes, suspension etc...we are already struggling to find performance part on these
 #350886  by teknikal
 October 15th, 2015, 2:31 pm
Here are a couple quick videos from lunch. Currently, I have the boost controller taken out since I was last tweaking on the tuning. I take it out so there's much less potential for damage if the AFR goes very lean. Without the controller, max boost is set by the springs in the wastegate solenoids, which is only about 6-7lbs. So basically the video doesn't seem very good to me - in real life you can hear the hiss and wine of the turbos, but not really at all in the recording. And trying to hold the camera with one hand is a real PITA - lol. I'll keep shooting for something better soon.

Not sure if the embed from youtube is working, so here are direct links

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 #350898  by 300maximilien
 October 15th, 2015, 8:27 pm
And he has one of those center vent pods also! Now you are just showing off!

But we love show offs around here!!
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 #350905  by remi
 October 16th, 2015, 4:58 am
I can't watch the videos at work with sound (open space), I'm so frustrated right now !!! I've to wait until tonight... lol
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 #350907  by FIREM
 October 16th, 2015, 5:41 am
Very interesting project. Final tweak's and tune would make it a BEAST !
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 #350911  by KxWarrior
 October 16th, 2015, 7:51 am
and air conditioning to boot....very nice!
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 #350916  by Null
 October 16th, 2015, 9:35 am
I can't watch the videos at work with sound (open space), I'm so frustrated right now !!! I've to wait until tonight... lol

it sounds like vrrroooooooooooom

hope that helps some