BoxsterLS376 introduction - LS3 conversion :)

[dcdrechsel]

Boxsterls376-question ..........I am wrapping up a ls1 in a 1999 996 build .One loose end interfacing the vehicle speed signal to the gm ecu .How did you do it ?
By the way thanks for taking the time to document your build .Both the build and the documentation are outstanding
Dave

[BoxsterLS376]

Hey man,

Yeah with this kind of modifications it will pretty much always be a "project car". To be honest mine dosen't really break much, aside from the water pump which was pretty frustrating, car is pretty damn solid. Just been doing oil changes and once I get motivated again i'll take care of the other small issues and the AC. So far so good~

Speaking of the water pump etc. yeah I certainly would not want to be responsible for anyone else stuff breaking. I have not come up with any solution other then not taking trips far from home, or getting a spare and keeping it with me in the car along with all the tools to fix it I've thought about getting a second pump as a backup so if there ever is an issue I could switch it on manually. I would think BMW pump may work as long as it delivers the same GPH or similar. Those motors are pretty high HP so I would think they do a good job.

Weather is starting to get warm down here so I may have to fix that AC sooner then I thought Should only be 2 wires but I've had so much going on lately just haven;t thought about it. I'm sure that first time crawling into the black seats after the Georgia sun has been beating down on them will motivate me!

Thanks!
J

Originally Posted by Bayley

I've gotten a few people who ask me "how much" to do this to their car as well. As I'm sure you're well aware, things are ALWAYS breaking or need adjustment.

Can you imagine if you did a swap for somebody else and the water pump died on THEM, and in turn smoked their ~$ 10K crate engine? Your name would be dragged all across the internet coals as the guy responsible for the failure. I can empathize 100% with your feeling of not wanting to do this for anyone else.

Speaking of water pumps, have you come up with any alternative solutions? I too have concerns about an electric water pump running at 100% duty cycle. Mine hasn't failed yet (knock on wood), but I figure it's only a matter of time.

I'm giving serious consideration into swapping a modern BMW electric water pump. The parts are actually engineered and tested to a standard, compared to the 3 second "It works, ship it!" validation testing performed on aftermarket components. Of course, I'd have to engineer a CAN bus gateway to set the speed, or otherwise run it in fail-safe mode... which is likely 100%.

I also played around with the idea of running a marine style sea-water pump. Of course, I would have to put this in place of the AC compressor and you just mentioned that you are trying to keep the AC. Originally, I assumed that I would want to keep the AC but there wasn't a single time last summer where I heard myself saying: "Maaan, I really wish I had that AC hooked up..."

Thanks for the updates, hopefully I'll see you on the road somewhere this summer.

Originally Posted by dcdrechsel

Boxsterls376-question ..........I am wrapping up a ls1 in a 1999 996 build .One loose end interfacing the vehicle speed signal to the gm ecu .How did you do it ?
By the way thanks for taking the time to document your build .Both the build and the documentation are outstanding
Dave

Greetings young Padawan Glad my build thread could help! Clearly you need to go back through and read it again because I have already gone over that.
Thanks
J



JUST KIDDING!

No big deal there and actually I dreamed it up in my head and then found that someone had already built what I needed! Check out TACH-ADAPT

I think it's like $80 and will make your life a lot easier! Good luck with the project, got any pictures or posts about it?
Thanks
J

[dcdrechsel]

Boxster ls376 -knew about the tach -was hoping you had connected the vehicle speed input from the abs to the gm ecu .The fundamental issue is what are the abs vss signal characteristics ?Once that is known should not be hard to convert to gm specs .
Perhaps you could point me to some likely sources to figure out what that signal is ?
Thanks

[BoxsterLS376]

Originally Posted by dcdrechsel

Boxster ls376 -knew about the tach -was hoping you had connected the vehicle speed input from the abs to the gm ecu .The fundamental issue is what are the abs vss signal characteristics ?Once that is known should not be hard to convert to gm specs .
Perhaps you could point me to some likely sources to figure out what that signal is ?
Thanks

Ahh ok my bad. Are you trying to get the traction control working or something? Not sure why you need the GM ECU to see the ABS stuff otherwise. Almost sounds like you are trying to get the speedo to work, which in that case I can't really help either as the Boxster picks up the speed from a plug on the transmission. Does the 911 pick up speed from the ABS?

Regarding the ABS signal stuff - The short answer to your questions is unfortunately no. Google was my best friend during the build but that was not something I ever dealt with, sorry.
Thanks
J

[dcdrechsel]

Originally Posted by BoxsterLS376

Ahh ok my bad. Are you trying to get the traction control working or something? Not sure why you need the GM ECU to see the ABS stuff otherwise. Almost sounds like you are trying to get the speedo to work, which in that case I can't really help either as the Boxster picks up the speed from a plug on the transmission. Does the 911 pick up speed from the ABS?

Regarding the ABS signal stuff - The short answer to your questions is unfortunately no. Google was my best friend during the build but that was not something I ever dealt with, sorry.
Thanks
J

Need the vehicle speed for emissions drive cycle tests .The ecu needs to know the car is moving The 996 abs right rear wheel sensor is used for the vehicle speed signal .The abs control unit does something to that signal .Don't know what and so far google doesn't know either .
Thanks for the speedy responses

[BoxsterLS376]

Originally Posted by dcdrechsel

Need the vehicle speed for emissions drive cycle tests .The ecu needs to know the car is moving The 996 abs right rear wheel sensor is used for the vehicle speed signal .The abs control unit does something to that signal .Don't know what and so far google doesn't know either .
Thanks for the speedy responses

You are welcome. Hrm... Yep never had to deal with that. I simply installed the GM ECU OBD plug in the trunk of the Boxster and tell the emissions guys to plug into that one. Voila~

GM ECU don't give a crap about speed etc. - are emissions very strict in your area? Any reason you can't just direct them to the GM plug? Here we just drive to the little booth, they plug in, see that it is OK, then you're good to go. No intense inspections of any kind.

Thanks
J

[dcdrechsel]

[QUOTE=BoxsterLS376;532424]You are welcome. Hrm... Yep never had to deal with that. I simply installed the GM ECU OBD plug in the trunk of the Boxster and tell the emissions guys to plug into that one. Voila~

GM ECU don't give a crap about speed etc. - are emissions very strict in your area? Any reason you can't just direct them to the GM plug? Here we just drive to the little booth, they plug in, see that it is OK, then you're good to go. No intense inspections of any kind.

Thanks
J[/QUO

Unfortunately I need the drive cycles .

[Bayley]

Unfortunately, I too have the same issue with vehicle speed signals.

The short answer is that there is no easy way to do this with simple wire splicing.

The PCM uses a frequency generated signal to measure inductive pulses through a "tone wheel" inside a GM transmission (usually on the output shaft). If you try to splice into an existing ABS sensor wires, you are now inducing a second frequency into a sensor that is already getting excited by the ABS module. Neither module will be able to read the sensor correctly in this case.

The best concept / idea that I came up with is to add an additional tone-ring to the inboard CV joint of a drive axle. Next, fabricate a bracket that would hold a factory GM vehicle speed sensor up to that ring. You would then need to recalibrate your ECU properly match the tone pulses to actual vehicle speed, but I see no reason why this shouldn't work.

Good luck and let us know if you come up with anything different.

[dcdrechsel]

Originally Posted by Bayley

Unfortunately, I too have the same issue with vehicle speed signals.

The short answer is that there is no easy way to do this with simple wire splicing.

The PCM uses a frequency generated signal to measure inductive pulses through a "tone wheel" inside a GM transmission (usually on the output shaft). If you try to splice into an existing ABS sensor wires, you are now inducing a second frequency into a sensor that is already getting excited by the ABS module. Neither module will be able to read the sensor correctly in this case.

The best concept / idea that I came up with is to add an additional tone-ring to the inboard CV joint of a drive axle. Next, fabricate a bracket that would hold a factory GM vehicle speed sensor up to that ring. You would then need to recalibrate your ECU properly match the tone pulses to actual vehicle speed, but I see no reason why this shouldn't work.

Good luck and let us know if you come up with anything different.

Dakota digital has a gps sender that I think will work .It is compatible with the gm ecu and looks like a simple , clean installation .If I hit many more dead ends that is what I will try .I keep thinking there is a way to take the speedometer signal and convert it to a ac sine wave for the gm ecu .So far -no .

[BoxsterLS376]

Greetings everyone,

Finally got off my ass made made an update video! Covers some of the things I have done to the car in the last few months as well as more information on wiring which everyone seems to have questions about.

Here are a few things which have been done since my last updates...

Black Sport Seats! Got rid of the worn our regular grey ones finally!

Replaced Porsche Wiring harness - Nothing cut, just rearranged!

Flashing coolant light on dash - FIXED!

Air Conditioning - INSTALLED AND WORKING!

Oil Cooler - FOUND ROOM FOR IT!!! w00T w00T!! It now lives behind the drivers side rear tire where the muffler should be~

Exhaust changes - I remade the down pipes into 2 pieces so now I have about a 6 inch section of pipe bolted to the factory manifold that has the Oxygen sensor on it and a V-Band clamp on the bottom to make removing the downpipes easier - Nice thing is that you can get the entire exhaust system off in like 10 minutes.

More exhaust - No more mufflers, no more straight pipes! I have now installed a pair of 2.5" resonators which gives it a very nice crisp tuned sound - still plenty loud though! Skip to the end of the video if you want to hear it


*** WIRING INFORMATION ***

I explained this in my video, but for the record... This is how my car is currently set up.

The Porsche ECU and the GM ECU run in conjunction with one another to make everything function properly - All Factory Hardware - no aftermarket harnesses etc.

GM Crate motor wiring harness - AKA the "ENGINE CONTROLLER KIT" GM Part #19354330

Get the installation guide for this and it will explain everything you have to do in order to get the Chevy motor working properly in the car from wiring to MAF and O2 sensor setup etc. Can't seem to find a link to it at the moment but will post it when I do.

PORSCHE HARNESS - WHAT DO I NEED?!?!

Keep all ground wires
Coolant Temperature Sensor Wires - Older models i.e.. 2000 have a 4 pin coolant sensor while later ones have only 2 pins. Either one will work with a bit of effort.
Starter wires - 2 -Power and exciter wire
A/C Compressor wire - You'll need this if you ever want to run A/C!
Transmission speedometer wire - 2 pin connector, longest wire in the harness - Makes the speedo work.
Engine compartment temperature sensor - didn't have this running before but can't hurt right!
Engine Compartment cooling fan wires - Figure I'll try and get everything working properly!

**THATS IT**
Everything else can be cut out or stashed off to the side!

**TACHOMETER**
BUY TACH-ADAPT!!! This will make your life much easier. TRUST ME.
TACH-ADAPT

That about cover things for now...WAIT.

OK so I last thing, If I can get enough interest and possibly and Guinea Pig I was thinking of doing a "BUDGET BOXSTER V8" build... Making the mounts myself and trying to figure out a cheap was to get an LS motor in these cars without breaking the budget. Just a thought for now but if you are thinking of doing a swap get in touch and maybe we can work something out.

One last thing before the video - Please do me a favor and help me out a bit. Trying to decide what to do with the rest of my life and may finally have an opportunity to start my own business If you have enjoyed my videos then please LIKE/SHARE/SUBSCRIBE to my YouTube Channel and I will keep you all posted as to what I'm doing!!

https://youtu.be/7VBXhLaYac8

THANKS!!!
J

[JRL]

Glad to see you are back. What is this NEW business opportunity? The car sounds perfect and WICKED

[BoxsterLS376]

Originally Posted by JRL

Glad to see you are back. What is this NEW business opportunity? The car sounds perfect and WICKED

Hey Randy,

Well the opportunity is just that for now, an opportunity. I need to try and make something of it! If you guys have any ideas I'm all ears!

I would like to do these conversions for people, although to be honest i'll probably have to do a 911 next just because those cars are a bit more popular then the Boxsters. Well that and find people who want to do them! Maybe come up with an actually reasonably priced conversion kit that is complete, haha.

Seriously though it could be a good opportunity to build some kind of automotive based business so if you all have any ideas let me know. I have a friend who is a good Porsche tech so I may be able to get him on board and actually start a shop but will need to do more then just that, plus not sure i'll be able to get him on board right away as he has a new wife and child on the way!

Oh yeah the car does sound good doesn't it?!?!

ALSO does anyone have a spare engine compartment temperature sensor they are not using?? Got my engine compartment fan installed now I just need the sensor which is gone with my old motor! DOH!

THANKS!
J

[BoxsterLS376]

Car is still for sale if anyone is interested. Time to move onto different things.
Thanks
J

[Disaster]

Originally Posted by BoxsterLS376

Oil Cooler - FOUND ROOM FOR IT!!! w00T w00T!! It now lives behind the drivers side rear tire where the muffler should be~

Wow, that was a lot of work. Sounds great. I can't help but think the oil cooler is an oil heater sitting next to the exhaust.

[D&D]

John, I started my V8 conversion shortly after yours on a 2006 BoxsterS - I've enjoyed your videos... but did not know about them till well into my conversion. I used the same crate engine as you did and really went through a lot of the same discovery processes as you. I'm up and running and all is working reasonably well - except that serpentine belt squeal!!! I noticed you had the same squeal on your videos and was wondering how you resolved it? I've already remachined a bunch of the Renegade mounts and am about to make some of my own to give more belt wrap on the crank pulley... so how did you do it? Would really like to sit down over a couple of beers with you someday. Thanks, Doug My email is dougbehning@gmail.com

[BoxsterLS376]

Originally Posted by Disaster

Wow, that was a lot of work. Sounds great. I can't help but think the oil cooler is an oil heater sitting next to the exhaust.

No not at all. It is not as close as it looks, closest part is the line that runs over it and it is several inches away. The cooler allows about an extra 1.5Q of oil and the cooler does just fine. I'll get some temps with my pyrometer next time I think about it.

Originally Posted by D&D

John, I started my V8 conversion shortly after yours on a 2006 BoxsterS - I've enjoyed your videos... but did not know about them till well into my conversion. I used the same crate engine as you did and really went through a lot of the same discovery processes as you. I'm up and running and all is working reasonably well - except that serpentine belt squeal!!! I noticed you had the same squeal on your videos and was wondering how you resolved it? I've already remachined a bunch of the Renegade mounts and am about to make some of my own to give more belt wrap on the crank pulley... so how did you do it? Would really like to sit down over a couple of beers with you someday. Thanks, Doug My email is dougbehning@gmail.com

Hi Doug, thank you, I'm glad my videos have helped! Yeah, the belt. UGH. Haha. That has been somewhat of an issue with or without the A/C. Without the A/C it was better, but with the alternator mount having the only adjustment you are pretty limited in both cases. I still had to cut/grind on the engine itself to get more adjustment as well as going through about 10 different sized belts to find one I could slip over the pulleys and still make it tight enough not to squeal

Currently I am running the A/C compressor and when I put it on I had to come up with a better solution to tighten it more. I decided to make an adjustable tensioning rod out of heim joints sort or like Porsche used on the old 944's - You can google Adjustable heim joint mount and you can see what I'm talking about. I ended up needing a pretty small one so I bought the parts from https://www.mcmaster.com and made a custom sized one. It didn't give me a whole lot more adjustability but has been ok, plus you still need to get just the right belt so it fits over the pulleys and doesn't max out. Now that the weather is cooling down it is starting to loosen up a bit so may need to look into it again.

The best solution would be to put a roller pulley in between the crank pulley and the alternator to get better wrap around the crank but really not enough room to do that, not without making some kind of custom bracket. Best advice I could give on the subject is to make sure your belts are 100% perfect before putting the motor in the car - otherwise it is a pain in the ass to deal with!

We could definitely get together for a beer sometime! I think we have a few V8 Boxsters down south here, maybe we can all get together at an event sometime??

[Pdwight]

preface this with I have never done a engine change in anything other than a Toyota and Honda. With all the speculation about a drop in engine for a replacement why has no one considered a Cayenne V8 ???. is it just too big or ??? the seem to be cheap compared to Boxster and 911 engines

[BoxsterLS376]

So I pretty much forgot about these... can't seem to get the original files from my buddy so hopefully this works!

These are spectator videos of the 1/2 mile drag racing event I did last year, some decent outside of the car sound.

Me vs. Mustang - not much of a race
https://www.facebook.com/jeff.merrick.378/videos/1154879711213532/

Me vs. 498 RWHP C6 Corvette - GOOD RACE!!!!
https://www.facebook.com/jeff.merrick.378/videos/1154882014546635/

Me vs. Porsche 928 - Not much of a race either, it was stock
https://www.facebook.com/jeff.merrick.378/videos/1154878871213616/


Someone please let me know if you can view these, I can but I want to make sure you can see them too.
Thanks!
J

[BoxsterLS376]

Originally Posted by Pdwight

preface this with I have never done a engine change in anything other than a Toyota and Honda. With all the speculation about a drop in engine for a replacement why has no one considered a Cayenne V8 ???. is it just too big or ??? the seem to be cheap compared to Boxster and 911 engines

Yep to big and probably to complicated, but mostly to big! It is a very tall motor and while like anything if you wanted to I'm sure you could make it fit but not without serious modification~

[JRL]

Hey John what are you up to these days?