Another Custom-Turbo Nytro

[Omega_5]

Hey Kenny,
I haven't talked to you since back in the Cobalt SS days.

Anyways, the turbo kit worked good. I got it all tuned up, and ran it on a few trips back home (north of Yorkton). It would rip hard on every sled in our group.

While the power was amazing and the boost rolled in fast, the nature of the power curve didn't quite fit my riding style. I do a lot of back country technical riding up in the bush areas, and found that the way a turbo rolled in felt off. It's probably cause of my tastes in power delivery; most of the vehicles I own are supercharged.
I ended up selling the kit to a guy who does a fair bit of mountain riding, in order to make way for a new build (which I'll post up in a few weeks).

What did I learn from this?
You can easily build a turbo kit, if you size the turbo right, and have the fabrication equipment readily available.
And... turbos are for the mountains, or high speed riders.


BTW, I'll check what's up with the pictures.

 

[kennyspec]

Yep last time I heard from you was in the cobalt days. Lol. I ended up building 3 turbo kits for my cobalt the last one being a gt3076 with a direct port meth setup. One of the meth jets got plugged on the dyno and it blew up sky high lol. Melted the piston and sleeve. Would of probably of made well over 425whp if it held through the pull.

Anyways if you could get those pics working again that would be awesome. I have a 08 mtx that I plan to turbo over the summer. May use a 2860 or maybe just a bit smaller not looking for huge numbers but want a fast spool. What did you do for am oil return pump and did you have any issues with it? Was the lag really that bad while in the tight stuff? I just can't picture it being a issue.

 

[Omega_5]

Shitty deal with the LSJ. Sounds like awesome power, though. Are you planning to rebuild it, or move on to other projects?

The 'lag' with the turbo wasn't bad, it just felt foreign to me. At low RPM's it was probably making 10-15% more power than stock... but it was getting used to having to modulate my thumb as the RPM's increased, as the spool would cause it to trench out on me. Having owned a turbo vehicle, you probably know what I mean.... turbo power doesn't feel as linear as NA does.

A 2860 should be fairly well suited for the nytro motor, in a 220+ application. If I recall, it's the same one Powderlites uses.

For the oil pump, I initially used a Facet pump from Powerlites. I later found out you can pick them up from NAPA -> 610-1051.
I pitched the facet pump, when I found out that it wasn't returning fast enough, and switched over to a flexible impeller pump (from Princess Auto) mounted at the front of the sled. That thing moved serious oil, and solved my oil return issue.
If you're planning to use a 2860, I bet you could get away with the Facet pump, considering the low oil requirement.
I wouldn't jump straight to the flex-impeller pump, as they can burn out easily if you aren't moving enough fluid.

 

[kennyspec]

Cobalt is back to stock and ready to be sold. I picked up a 2010 camaro ss to play around with now.

I should be fine with that lag. I'm used to throttle control from the cobalt days.

I was planning on returning the oil to a bung welded to the top of the oil tank. Or would it be
Better to return it to the side of the case?

 

[kennyspec]

I will try that Napa pump. The 2860 shouldn't move that much oil with a feed restrictor.

Also at about 40 or 50 MPH driving down the trail was it in boost or vacuum at a constant speed? What afr did you run while cruising? I am planning on using the pcv with auto tune and would like to run at 14.7 afr while cruising but don't know if that is a good idea to run it that lean if its making boost at trail speeds. Or should afr be dependant on engine load and not psi?

 

[tjc]

I use the same pump (facet from NAPA), works well with a catch can under the turbo.

I have a Mitsu 16 G rear mount on my Nytro. I was around 1-2 pounds boost last year when cruising. If I kept an eye on it I could keep it at 0 boost while keeping a good clip cruising.

 

[Omega_5]

Just cruising down the trail, you're generally in vacuum; 75-ish kpa. Breaking new trail, you start to get in to the boost regions.
I tuned my sled like any other speed density motor; as a factor of RPM vs manifold pressure. I wouldn't really trust Alpha-N (throttle based) control on a turbo set up like this.

I went with the RapidBike setup from Powderlites, but I've heard the PC3 and PC5 works fine. Maybe talk with Ulmer Racing, as I know they've have modified the Power Commanders to work from a MAP sensor, as opposed to a TPS. From what I've heard, the guy that bought my turbo kit is planning to go with a PC3 combo from Ulmer. I'll have to follow up with him later in the season to see how he likes it.

Does the PC5 allow ignition control now? If you're planning to run any more than 7psi, I highly suggest an ignition controller. It likes to ping at the top end on stock timing. Plus you get the benefit of playing with the bottom end timing for a faster spool.

One thing to note about the Nytro; it's not like tuning a road car. It gets very grouchy if you try to run it near stoich, and makes it a pain in the #*$&@ to start when it's cold. I found a nice middle ground at about 13.5 for idle and cruising. Started good, but far from the 12.0 pig-rich it was from factory.
I chose to blend the fuel map at a few points to make it more safe. At about 80-85kpa in the manifold, I started to richen it up to about 12.5, then ramped it to the usual boosted 11.6-11.8 after 100kpa.

 

[tjc]

I see you guys have a "personal" dialogue going on but I was hoping to chime in. You mentioned deto above 7 psi. I dont have the tuning abilities you have but I was wondering what fule you used at that level?

I have been right around 7 psi on mine and Im thinking about going to 91 plus torco to an octane level around 95 or so.

 

[kennyspec]

I'm planning on running it on pump at mostly sea level. Maybe 5 to 7 psi Max. I don't really like the idea of a headshim. Maybe upgrade the pistons to lower comp later on. I believe the PC5 does have timing control and you can buy a map sensor add on to make it map based instead of tps based. Does the nyttro have a knock sensor stock? How could you tell it was knocking in the top rpm? Sound like dimes being thrown at the engine? lol.

Did you run the stock air box temp sensor in the plenum or just leave it under the hood? Also what did you do with the stock map sensors? I am assuming they are only 1 bar sensors? (Assuming they can only read vac and Max out at 0psi?)

 

[Omega_5]

I see you guys have a "personal" dialogue going on but I was hoping to chime in. You mentioned deto above 7 psi. I dont have the tuning abilities you have but I was wondering what fule you used at that level?

I have been right around 7 psi on mine and Im thinking about going to 91 plus torco to an octane level around 95 or so.

I just ran 91 all the time. If you don't have the ability to retard the timing, a bit of octane boost or cutting the gas with race fuel should solve your problems.

I'm planning on running it on pump at mostly sea level. Maybe 5 to 7 psi Max. I don't really like the idea of a headshim. Maybe upgrade the pistons to lower comp later on. I believe the PC5 does have timing control and you can buy a map sensor add on to make it map based instead of tps based. Does the nyttro have a knock sensor stock? How could you tell it was knocking in the top rpm? Sound like dimes being thrown at the engine? lol.

Did you run the stock air box temp sensor in the plenum or just leave it under the hood? Also what did you do with the stock map sensors? I am assuming they are only 1 bar sensors? (Assuming they can only read vac and Max out at 0psi?)

Nah, the nytro doesn't have a knock sensor. I was measuring knock with a bolt on knock sensor system I use for tuning quads and sportbikes. Perks of running a part-time tune shop, I guess.
With that said, though, you can tell if they are knocking without a sensor. The nytro tends to sputter when it gets in to knocking, on the low end. The top end isn't quite as obvious.

I ran the IAT sensor into the top plenum of the intercooler. Most turbo kits just tape it to ambient, but I liked the idea of utilizing the factory intake temp timing retard, for the warm days or if the intercooler got a bit heat soaked.

For the stock MAP's... they are indeed only 1 bar. The OEM ECU requires them to run properly, so they stay. They don't have a fail setting, like OBD2 cars... they just max out under boost, and hold voltage. For the piggy-back module, I tied the 2 bar MAP into the same vac line that feeds the main OEM MAP (the one on the right).

 

[kennyspec]

thanks for the help, i know my turbo build is a ways away yet but it doesn't hurt to have all the info i need before i start the build.