10 year old Gturbo

SNLC

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Looks like I am pretty much maxed out on the pump, @SNLC who is doing work on the pump for you?
Gturbo, sent the pump to them. They are sending it back with the turbo and a billet flywheel and clutch. Not cheap but it is how the customer wanted to go and no argument from me since I know it will all be set up just right.

Cheers
 
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I'm curious why type of transmission never gets mentioned when discussing turbos. I haven't spent much time driving autos, but surely low rpm spool is basically unnecessary/unnoticed on them? But driving the same engine with a manual gearbox it becomes a massive driveability factor, moreso than maximum boost or high rpm performance.

Is this why some people report positive results of 'hi flow'/large compressor wheels, when others find the opposite? The autos are never accelerating at the lower revs where the oversized compressor won't spool up.

This has been on my mind for a while, but I mention this now because the OP reports being a little underwhelmed from the difference between a ct26 and a gturbo.
 
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@Loober your results are interesting. Changes in mine were dramatic (temps on pyro during load) but I did the turbo and FMIC at the same time and that probably accounts for my experience. I noticed a big change in driving around home area, and then also when I had take it off cruise control and slow down on the big grade just outside Pendleton on I84 up to Umatilla National Forest to be at a safe speed for the curves. Compared to a number of trips through this area in years prior...It just kept wanting to pull.

My fuel pin had been modified already, so I did not touch the fuel, or any other setting, as I wanted a straight across comparison: Had been running the stock CT26 at 14-15psi for 80,000kms and as mentioned the fuel pin had been modified. I was always having to back out of the throttle at 1250f as I was running it to the pyro. My replacement Gturbo is not a coloured wheel either, but was purchased in late 2014, so perhaps some of the difference is in the mapping as well.

I did work with the fuel pin a couple years after the install and adjusted it a bit more. I used a paint pen to mark where the pin rides and increased spring tension, but got to the point where I believe the lid needs to be modified ala @yotahed info here. I thought gturbo's instructions where in the fuel pump mod thread, but at a quick glance can not seen them.

I did not adjust the wastegate beyond how it came as setup, but use a Hallman Boost Controller and have it set to 20psi after my initial trips to assess changes.

hth's
gb

Grunter Turbo.jpg
 
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Feb 29, 2008
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Wichita Falls TX
 
 
I had A factory CT 26 in my ft, fmic and 3 inch exhaust. Tuned to about maximum, a little more fuel and it would start to smoke too much and then high egt. Had the tune like this for 3-4 years.

Put on a 2018 grunter extreme and didn’t notice any big difference. But when I started grinding the Android pin an playing with fuel the fun started. A lot more power, no smoke under full pressure and I couldn’t get any high egt either. 22 psi!

Now my ft is detuned... waiting for the npc1300 to be installed.
 
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Jun 10, 2007
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Kiwiland
 
 
I'm curious why type of transmission never gets mentioned when discussing turbos. I haven't spent much time driving autos, but surely low rpm spool is basically unnecessary/unnoticed on them? But driving the same engine with a manual gearbox it becomes a massive driveability factor, moreso than maximum boost or high rpm performance.

Is this why some people report positive results of 'hi flow'/large compressor wheels, when others find the opposite? The autos are never accelerating at the lower revs where the oversized compressor won't spool up.

This has been on my mind for a while, but I mention this now because the OP reports being a little underwhelmed from the difference between a ct26 and a gturbo.
Depends on your auto and torque converter really. Some are pulling away at idle and others need 1500rpm to move off the spot. If you get a drive of a current Nissan Navara you'll see the 7sp auto never lets it go below 1500rpm. I suspect that engine would fall on it's face below that.

As far as user reports for a specific mod. If 50% think it's awesome and 50% think it does nothing, it usually does nothing.
 
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@Dougal I did some tuning with the aneroid pin and star wheel, here is where I am at, the picture shows the pin travel on the aneroid pin marked with the red line, at ~22psi max, the pin stops traveling 1-2mm above the taper. Note I also have the pin rotated to the most aggressive profile. I feel my fuel is pretty much maxed, I have the idle set screw all the way out and my idle is at 900, which is on the high side, i tried adding more fuel then that and I dont feel any diff in power, the idle just goes up. EGT's are way safe 900-1000 at WOT, and no noticeable smoke

Based on the stopping point on the aneroid pin it needs to travel further down the skinniest part to have max fuel delivery correct? I have the star wheel adjusted all the way down, i.e. least amount of preload possible with these results. So I am getting max fuel only at the peak boost, and not through more of the boost range. So if I am understanding this correctly, I either need more boost to force the pin down sooner, or grind the ramp part of the pin to give it more skinnier profile down lower on the pin? What about a softer spring?
 

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It doesn't matter how much you screw in the max fuel screw you'll never get the maximum fuelling with that factory cut profile on the aneroid pin, the profile needs to get deeper into the pin which gains more fueling without even having to touch the max fuel screw. This pic has been getting around on here for years but it shows very clearly what needs to be done to get more fueling. The follower pin with the stock profile only moves about 4mm in depth but it can actually move slightly more than 6mm giving a bigger range of compensation and more fuel.

aneroid pin.jpg
 
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I
@Dougal I did some tuning with the aneroid pin and star wheel, here is where I am at, the picture shows the pin travel on the aneroid pin marked with the red line, at ~22psi max, the pin stops traveling 1-2mm above the taper. Note I also have the pin rotated to the most aggressive profile. I feel my fuel is pretty much maxed, I have the idle set screw all the way out and my idle is at 900, which is on the high side, i tried adding more fuel then that and I dont feel any diff in power, the idle just goes up. EGT's are way safe 900-1000 at WOT, and no noticeable smoke

Based on the stopping point on the aneroid pin it needs to travel further down the skinniest part to have max fuel delivery correct? I have the star wheel adjusted all the way down, i.e. least amount of preload possible with these results. So I am getting max fuel only at the peak boost, and not through more of the boost range. So if I am understanding this correctly, I either need more boost to force the pin down sooner, or grind the ramp part of the pin to give it more skinnier profile down lower on the pin? What about a softer spring?
I think a firmer aneroid spring would help. From there I would grind the pin. Especially if you can rotate it and grind the other side so you can always go back to your current setup.
 
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@KiwiDingo thats a great graphic, have not seen it before, kind of confirms the conclusions I was coming to, are you aware of anyone selling these with the modified profile? or stock ones to have just in case.
 
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No sorry, I don't know of companies selling them already ground to a profile. When I do all my pins I do them from blank ones I get from local machining shop to make up for me.
 
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@KiwiDingo thats a great graphic, have not seen it before, kind of confirms the conclusions I was coming to, are you aware of anyone selling these with the modified profile? or stock ones to have just in case.
There is a Zeal Power Rod which is modified already and 4WheelAuto still lists them. I believe they come out of Japan but not confirmed. I have never seen the profile details posted so do not know how close to the above diagram it is.

The instructions for tuning the G-Turbo are buried somewhere here. Have you contacted them to see if they will email you a copy?

There's been discussion about finding stock fuel rods on various threads in the past and no one has come up with a good part number yet.

hth's and and happy tuning.

gb
 
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@KiwiDingo thats a great graphic, have not seen it before, kind of confirms the conclusions I was coming to, are you aware of anyone selling these with the modified profile? or stock ones to have just in case.
I'd love to know the source of this diagram.

I don't think it's an ideal profile. There is limitations in the governor linkage rods and the housing that prevent all of that grind being useful.

There's some good discussion about this in the official fuel pump tuning thread.


I sketched my thoughts on a grind that could make better use of the available movement in the governor linkages and housing after carefully measuring the limits of both on a pump in pieces on the bench.
 
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I am talking to a machine shop about manf some locally, can anyone weigh in on the type of metal they are made off.
 
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@KiwiDingo thats a great graphic, have not seen it before, kind of confirms the conclusions I was coming to, are you aware of anyone selling these with the modified profile? or stock ones to have just in case.
@torfab shows a pin on their website:

Torfab 1HD-T FT Pin

I don't know if that's stock, modified or fabricated, but if they've fabricated it, it's probably worth talking to them to get some details or seeing if they can make one to suit your needs.
 
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@MonsterCruiser thanks for the lead, that is a good plug and play option but pricey, I am thinking folks that are interested in this sort of mod have the means to grind a pin themselves, I am shooting for ~$20 - 40 range for blanks that way its an affordable option for people to test out different profiles and see what works best.
 
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I am talking to a machine shop about manf some locally, can anyone weigh in on the type of metal they are made off.
They are case hardened after machining, and polished.
I'm no metallurgist, but some kind of tool steel the can be hardened after machining and grinding would be best.

They are also made to a very close fit in the sleeve they ride in.

If you grind a pin, you need to polish the ground surface too to prevent wear, and so you get a smooth action with the follower pin

I've seen pics of Aneroid pins that are too soft and have had a groove worn into them by the follower pin which is also hardened.
 
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EDIT: Just caught up on the the thread... you already bought the Torfab one. Admin: feel free to delete this post.


@KiwiDingo thats a great graphic, have not seen it before, kind of confirms the conclusions I was coming to, are you aware of anyone selling these with the modified profile? or stock ones to have just in case.
@torfab also sells a modified profile pin, here in the U.S.
 
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