Toyman! said:Any issues running a catalytic converter in the factory location? I know most people rip them out but I really don't want to smell like a 1960 vehicle all the time.
Will the OEM cat work or do I need to consider swapping to a high flow?
We run factory cats in the factory location on our NC and ND kits. It's certainly possible. Keep in mind that a cat will increase exhaust restriction which will have an effect on spoolup and cooling and detonation. A high flow will help.
I am quite new in the turbo dabbling world, and it's a "belly button" turbo LS at that, but I've been striving for "safe" above all.
In building the engine I smoothed and polished the tops of the pistons and inside the combustion chambers all the way to rouge. My theory is it would keep more heat in the chamber. Did it work? I dunno... Safe?
I opened the ring gaps up to 0.026"/0.028" on a 4" bore, which is theoretically good for 22psi boost (0.0065 per inch of bore). Turns out my PCM can only do 2-Bar. Oh well. Large rings gaps are safe.
I did ARP head studs just to be safe.. They say you don't need them, but "overkill is my second most favourite kind of kill."
I plumbed 1/2" fuel feed and 3/8" return. I'm running a Walbro 450. I decapped twenty four LS injectors and flowed them until I had eight the same.
I'm using HPTuners. I started with the softest wastegate spring which gave me 4psi at the intake, and slowly worked my way up datalogging and tuning and increasing boost with a boost tee. I'm at 9psi now. I tune on 91 octane, and drive on 94 just to be safe - there is no guarantee I can get 94 everywhere, and there is no E85 in my area. I'm not getting away with as high a spark timing numbers as others proclaim, but it's all in a heavy truck. not a stripped Camaro.
I have a Snow water/meth injection that sprays washer fluid at 7psi. Apparently a 50/50 mix of water/meth brings power, but I can get washer fluid anywhere, and it adds safe.
Am I leaving power on the table? Oh probably. But its been working so far. I still want to turn the wick up, but I'm both a little scared of doing so - out of risking the safe, but honestly a turbo 6.0L in a '61 Chevy pickup with zero traction/stability/abs/airbag all on 245's is exhilarating enough as it is.
(big grin)
In reply to Keith Tanner :
Braces can do non-intuitive things with expansion. We had a brace on our Mazdaspeed Miata downpipe and they cracked. Took it off, no more cracks. Had the same experience with the BBR kit for the ND.
Many turbos (and downpipes) are braced from the factory on a lot of cars, even with heavy cast manifolds. With a tubular manifold, I'd risk the chance of a brace causing an issue Vs. the likely hood of an unsupported turbo cracking the manifold. The downpipe weighs much less than the turbo/downpipe combo hanging off the manifold, I wouldn't worry nearly as much about bracing the downpipe. Plus this is for a 4x4 truck, bouncing around off road is added stress.
Maybe something like this that would support some of the weight but still allow for expansion?
Toyman! said:Any issues running a catalytic converter in the factory location? I know most people rip them out but I really don't want to smell like a 1960 vehicle all the time.
Will the OEM cat work or do I need to consider swapping to a high flow?
One possible CEL is for slow light off. But that's about it. On the other hand, you won't worry about temp protection- as the turbo takes out a lot of heat. It will work quite well.
Keith Tanner said:Toyman! said:Any issues running a catalytic converter in the factory location? I know most people rip them out but I really don't want to smell like a 1960 vehicle all the time.
Will the OEM cat work or do I need to consider swapping to a high flow?
We run factory cats in the factory location on our NC and ND kits. It's certainly possible. Keep in mind that a cat will increase exhaust restriction which will have an effect on spoolup and cooling and detonation. A high flow will help.
It's not too likely that the catalyst will restrict the flow noticeably for some thing that boosts less than 1 atm.
Toyman! said:In the same vein, EFI Live or HP tuners.
I have the HP Tuners hardware and account. EFI Live is apparently more open as far as what is accessible in the ECU.
Both of them will flash the E67 ECU with a 2.5 bar map and run open loop and speed density under boost.
Why would you choose one vs the other?
What do you gents use since y'all will be the gents I'm asking questions?
How modern is this? If it's from the last 15 years, it should have a WB and will be capable running closed loop 100% of the time. Choose that.
As for the boost- 2.5bar of boost is 2bar more than it sounds you want to run, is there a 1bar option?
And hopefully the engine is originally speed-density. GMs calculation is really odd, so you surely want the one they came up with.
The E67 is not wideband capable.
2.5 bar is the absolute pressure range of the sensor. It strikes me as odd because I didn't know GM had a 2.5 bar MAP in their inventory, I've only ever seen 1, 2, and 3-bar MAP. The only time I've ever seen a 2.5 bar MAP was soldered to the circuit board of a Megasquirt.
In reply to Pete. (l33t FS) :
Some reading shows HP Tuners has an updated OS for the E67 that will allow it to run a 2.5 bar sensor and operate in MAF and speed density mode as well as has a MAP-referenced boost enrichment table.
From HP Tuners.
2.5 Bar MAP - Speed Density (E38/E67 ECM)This enhancement contains the following features:
2.5 bar (255 kPa) max MAP sensor support (calibration capability for GM 0-5V linear MAP sensors)
Rescaled High MAF table supports up to 15400 Hz with 300 Hz resolution, also supports airflow up to 1024 g/sec
New VE tables with 33 x 33 cell resolution each and configurable MAP and RPM axes (choose your own resolution)
Charge Temperature based VE multiplier table, configurable axis
TPS based VE multiplier table, 33 x 17 cells with configurable TPS and RPM axes
MAP referenced "Boost Enrich" table
Boost Enrich MAP threshold and hysteresis value
Both MAF and Speed Density mode supported
Boost based fuel cut, selectable MAP threshold cuts fuel to all cylinders when exceeded
Rescaled fan temperature axis 163-250F (73-121C), stock is 192-250F (89-121C)
Toyman! said:Any issues running a catalytic converter in the factory location? I know most people rip them out but I really don't want to smell like a 1960 vehicle all the time.
Will the OEM cat work or do I need to consider swapping to a high flow?
The most restrictive cat is the one in the manifold, which you will be removing . The secondary cat is not bad, but a proper high flow won't hurt.
In reply to Toyman! :
Hmmm.... I have an E38 pcm in the rx8. I may have to look into this!
Another question.
The 3.7 has VVT. Is there any advantage to changing the VVT tune or am I better off leaving it at the OEM settings?
I know that turbochargers work well with mild cams that have little overlap. How much overlap does a VVT engine end up with at high RPMs?
Toyman! said:I know that turbochargers work well with mild cams that have little overlap.
No more than anything else.
That's a misconception. The camshaft you choose is based on your desired RPM. I would keep the VVT
In reply to Peabody :
The VVT will be staying. I'm just wondering if there is any advantage to tuning it or if my best bet is to leave it alone.
i'd vote to leave it on, i think (at least on LS stuff) the VVT activates at low RPM to improve low-end which is what you're trying to improve anyway?
In reply to budget_bandit :
Is it an on/off thing or is it variable?
I haven't actually pulled the tune off of the ECU to even look at it yet.
wvumtnbkr said:Make sure your turbo oiling is correct.
One thing that is often overlooked is that if you shut off a turbo engine after a hard run, the heat generated can cook the oil in the bearings and the ash will affect turbo life. I used a turbo saver that was nothing more than a steel cylinder plumbed into the oil line to the turbo bearings with a one way valve. When the engine rubs the cylinder fills with oil, and when you shut off it slowly bleeds cool oil into the turbo bearings.
wspohn said:wvumtnbkr said:Make sure your turbo oiling is correct.
One thing that is often overlooked is that if you shut off a turbo engine after a hard run, the heat generated can cook the oil in the bearings and the ash will affect turbo life. I used a turbo saver that was nothing more than a steel cylinder plumbed into the oil line to the turbo bearings with a one way valve. When the engine rubs the cylinder fills with oil, and when you shut off it slowly bleeds cool oil into the turbo bearings.
Got a link?
IME, the "turbo timer" or "turbo saver" thing was really only a major issue in the 80s and 90s before water-cooling became ubiquitous on turbos. Nowadays it's really not much of a concern -- if you've been running it especially hard (say doing a track session) then letting it idle for a few minutes isn't a bad idea but other than that I wouldn't worry about it.
Toyman! said:In reply to budget_bandit :
Is it an on/off thing or is it variable?
I haven't actually pulled the tune off of the ECU to even look at it yet.
VVT is variable. That's what the V stands for :) You can disable the whole function, but when it's active it's a full map and not just on/off.
In reply to Keith Tanner :
Is it tunable in HT Tuners?
Never mind, I found it.
codrus (Forum Supporter) said:IME, the "turbo timer" or "turbo saver" thing was really only a major issue in the 80s and 90s before water-cooling became ubiquitous on turbos. Nowadays it's really not much of a concern -- if you've been running it especially hard (say doing a track session) then letting it idle for a few minutes isn't a bad idea but other than that I wouldn't worry about it.
And if you locate the turbo below the high water line, so there will be some natural water movement when the engine is shut down. It's what OEMs do.
Toyman! said:In reply to Peabody :
The VVT will be staying. I'm just wondering if there is any advantage to tuning it or if my best bet is to leave it alone.
I had originally said that mine was altered when we tuned it but I couldn't remember for sure so I edited it. I think I recall him bringing the VVT in 1000 RPM sooner
alfadriver said:codrus (Forum Supporter) said:IME, the "turbo timer" or "turbo saver" thing was really only a major issue in the 80s and 90s before water-cooling became ubiquitous on turbos. Nowadays it's really not much of a concern -- if you've been running it especially hard (say doing a track session) then letting it idle for a few minutes isn't a bad idea but other than that I wouldn't worry about it.
And if you locate the turbo below the high water line, so there will be some natural water movement when the engine is shut down. It's what OEMs do.
The term to google is "thermal siphoning". A DIY build that starts with a manifold has no control over the turbo placement, but the rotation of the center section is important.
You'll need to log in to post.
