ECOTEC 2.0 LTG SWAP

[Slidin Gator]

It really comes down to the length the wires are not twisted and distance from noise source.

Solder, heat shrink and retwist and you should be fine. You do want to use TWP wire for your extension. When you get done making the harness, put it in a drill and twist the splice tight, throw another layer of heat shrink to hold the twist and move on. As said, always route away from ignition coils. EMF drops off as 1/in^3 (as in 1 over distance from the noise source cubed) so a few inches is worth a lot.

[br,lc,LA]

The only twisted pair you have to worry about is the GMLAN white and blue. You are not running FPCM which is the other twisted shielded and shunted pairs.

Solder the joints and shrink tube them and move along. The wiring is not complicated at all... try to keep the amount of solder joints minimum... usually only need to extend accel pedal and GMLAN only... the rest of the harness should stay factory and put the ECM on the engine stand.

[FISHSTICKER]

Thanks for that info guys.

[FISHSTICKER]

The UAW strike is keeping me from getting an O2 sensor. After talking to 6 different retailers one finally told me what the issue was.

[Deano]

Betcha a nickle, you can find a knock-off on Ebay this afternoon. (Even if only for temporary use)

[FISHSTICKER]

If I was ready to crank it I would. But I’m not there yet so i’ll wait for the GM flavor. I don’t think either side can take much more of this strike. Hopefully they will reach an agreement so those people can get back to work.

[OneBFC]

https://www.rockauto.com/en/catalog/cad ... ensor,5132

[FISHSTICKER]

Thanks! Order placed should be here by next Monday. I was checking locally and no one had one or could give a delivery date. Now to see if they actually have one In stock that ships.

[FISHSTICKER]

OD of turbo outlet is a little more than 1.8”. OD on intake connection is a little more than 2.8”. So on those ends I guess I will find the fittings with a ID of about 1.75” and 2.75”. I’ll pick a intercooler with 3” inlets and outlets. For the piping I am planning to transition to 3” for the turbo outlet as quickly as possible and use all 3” pipe.

[OneBFC]

OD of turbo outlet is a little more than 1.8”. OD on intake connection is a little more than 2.8”. So on those ends I guess I will find the fittings with a ID of about 1.75” and 2.75”. I’ll pick a intercooler with 3” inlets and outlets. For the piping I am planning to transition to 3” for the turbo outlet as quickly as possible and use all 3” pipe.

That's a commonly used plan. It will work well configured that way.

[br,lc,LA]

be cautious about oversizing... keep your runs short as possible... remember the turbo has to compensate for the volume of the piping and intercooler and lag can be exacerbated by an oversized system.

[OneBFC]

be cautious about oversizing... keep your runs short as possible... remember the turbo has to compensate for the volume of the piping and intercooler and lag can be exacerbated by an oversized system.

Honestly dont think you can have any issues with sizing. This "dont go too big" advice for turbo plumbing is as old as the hills. I have owned nothing but turbo charged engines since 1989. Everything from cars, trucks boats and all manner of toys. All have been turbo charged. Every single engine.

Not once have I ever had a problem with too large of a pipe diameter. Even on tiny little 600cc engines.

I wouldn't worry about it too much.

From a fluid perspective, you want the velocity of the air as it goes through the intercooler to be as low as possible so it can shed heat to the IC core. Large diameter pipe and IC inlets/outlets produce lower air velocities.

There is a reduction in size near the throttle body that accelerates the air to a velocity that works best with the intake / cylinder head so no matter what you do before that, it won't impact what goes on inside the manifold and head.

"Lag" is not an issue on the LTG. Do not sweat it at all.

[FISHSTICKER]

Well.....I was looking for turbo charge pipe fittings last night. 1.75” or 2.75” does not appear to be a common size. Not even as a transition fitting. Most of the specs for the parts I was looking at did not give ID/OD info. The ones that did appeared that the listed diameter is the ID of the fitting. I ordered a 2.5”x1.5” silicon reinforced fitting to see if it will work on the turbo discharge and intake connection. I was hoping to make the transition to 3” in one fitting. I have not found one that makes the jump. That made me think about dropping down to 2.5” pipe. Thats a 30% reduction in cross sectional areas which means 30% increase in velocity . I don’t know what kind of performance penalty that would result in. The research I have been doing indicates the little motor could make 450HP at the crank with let’s say medium effort. I don’t know if I would ever push it to that level but I could see myself in the 380HP range for sure. Is 3” overkill for that? Probably no reason to worry about stacking two fittings and just go 3” like I was originally thinking. Making my TODO list for the weekend while sitting in this less than interesting confrence.

[FISHSTICKER]

Turbo charge pipe gasket. Gasket between the turbo housing and the pipe carrying the compressed air. $50. I have not put my eyes on one in person but looks to be a regular flat gasket. Surfaces are smooth. What do you think about high temp silicone? Anyone know of a type of gasket material that I can buy a sheet of that will work in this application? Seems like a scalper price for what it is. Not talking about the exhaust side. I was happy that one was only $70. (Edit price was only 14.99 not 70)

[hogdoggin]

Mine is a lhu different but it has a o-ring on the outlet side. I don't know if a flat gaskets going to hold those kind of boost pressure. I was looking at your pictures I see the factory looks to be stainless is still on the engine. Did you pull that off to see what's in there? Also you could probably cut that off where you have about 2" or so sticking out. Than weld a lip around the edge so your coupling doesn't come off.

[br,lc,LA]

HPS Silcone is best I've found in my searches. Also available via Amazon at better pricing sometimes

1.75x2.75 reducer
http://www.hps-siliconehoses.com/hps-45 ... 4-ply.html

Couplers are quoted as ID, tubing is quoted as OD. T-Band clamps are quoted for tubing OD but be careful to make sure you all for 4-ply silicone thickness which may require you to upsized the clamp to get it on... you end up having a long exposed thread when you tighten.

Tubing can be found at cxracing in 2.75
https://www.cxracing.com/aluminum-pipin ... piping-kit

https://www.cxracing.com/aluminum-pipe- ... minum-pipe

[FISHSTICKER]

Pretty sure it has to be a flat gasket the one photo I saw looked to be a plain flat grey gasket.

[FISHSTICKER]

I guess an oring could sit in that recess where the pipe /flange junction is but I would think they would have done it different.

[FISHSTICKER]

The factory charge pipe has a nice bead on the end to hold a silicon hose...it’s just hiding under the Cammo duck tape. Thanks for those links and info. I was wrong about the composite steel gasket on the exhaust side of the turbo. I thought it was $70. It came in today and the invoice says it was 14.99. I don’t know what the heck I was remembering. I must have been thinking the two together was about $70.

[FISHSTICKER]

Just noticed the ECM has no mounting holes or threaded bosses to secure it. How is it held in place in a car?

[FISHSTICKER]

Did you guys just cut the transmission and other unused connectors off, seal the ends of the wires and leave the rest in the harness? Or did you take the time to unpin and pull all the unnecessary wires out? If any of those unused wires short could that make some ECM smoke or other issues?

[br,lc,LA]

E39, E80, or E92 ECM? There is a clamp style bracket for E80 and E92... the E39 has holes.

I've done both unpin and cut seal, but I made sure all the +5v were sealed separately from the low references so you wouldn't have any chance of a false signal (you'll also tune out the CEL codes. You don't need to worry about "smoking" ECM unless you short a 12v signal to a low reference pin which can happen if you let the MAF plug side get wet (speaking from experience).It actually didn't smoke it, it made the sensor read an "in range" false signal and smoked the rings and turbo!

[br,lc,LA]

Compressor side out is a copper gasket with knurl shown in attached.

https://www.gmperformancemotor.com/mm5/ ... 332838.jpg

[FISHSTICKER]

I’ll go ahead and order the GM gasket if it’s copper. And probably take the easy way out and cut and seal the wires individually rather than pull them all the way out. I don’t remember what ECM I have I’ll Check it in a bit. Thanks for the info.

[FISHSTICKER]

Computer is a E80.