10 year old Gturbo (2 Viewers)

[KiwiDingo]

Nice @Indestructible 47. I had one of those grunter extremes on my FT, spool demons! I made 148kw and 565Nm but I adjusted mine to only 18psi as my injector pump was stuffed.

 

[Saltgrinder]

Hi all,

I have acquired a Gturbo for 1HDFT motor that has never been run but purchased 10 years ago. I realize Gturbo has improved and evolved their product quite a bit over the last 10 years, should I be concerned running their earlier turbos?

Contact GTurbo , they are pretty forthcoming with info .
I called in to see them 3 weeks ago for a tune on my 80 , Grahame and the guys there are pretty honest and helpful

 

[Loober]

@KiwiDingo @Jroc561

Alright guys here it is, it does not have a colored wheel.

Another questions, whats the deal with the adjusting nut on the rod for the wastegate, should I worry about getting it adjusted before putting the turbo on? It will be a PIA getting to it once its installed.

 

[Greg_B]

Maybe run a manual boost controller, then your adjustment to what you want is easy. A search of "manual boost controller" should give lots of ideas and options.

hth's
gb

 

[Loober]

I do have a manual boost controller, so thats all that adjustment rod does is preset the opening pressure on the diaphragm?

 

[KiwiDingo]

Another questions, whats the deal with the adjusting nut on the rod for the wastegate, should I worry about getting it adjusted before putting the turbo on? It will be a PIA getting to it once its installed.

Most turbo's need about 2 turns of preload on the actuator rod for optimal operation. Gturbo's (especially the older versions) are designed to run a bit more EMP than others and normally require a few more turns of preload, I think from memory I had about 8 turns on my older version grunter. This is also evident in the modified gate arm you can see in your pictures which clearly shows the gate arm/lever is about twice as long as a standard arm which gives greater holding pressure onto the gate to avoid it being blown open by EMP. There's good and bad points to doing this and it will all come down to individual vehicle setup and performance required, keep in mind the longer the gate arm and/or the more preload you place on the gate the less range of movement you have in the gate full open position. Yes you are correct in thinking it's a PIA to reach and adjust when it's installed on the vehicle but it's still doable. I found using a scribe to remove the E-clip was the easiest method but they tend to fly off and are never to be seen again so make sure you have some spares.

 

[Loober]

Most turbo's need about 2 turns of preload on the actuator rod for optimal operation. Gturbo's (especially the older versions) are designed to run a bit more EMP than others and normally require a few more turns of preload, I think from memory I had about 8 turns on my older version grunter. This is also evident in the modified gate arm you can see in your pictures which clearly shows the gate arm/lever is about twice as long as a standard arm which gives greater holding pressure onto the gate to avoid it being blown open by EMP. There's good and bad points to doing this and it will all come down to individual vehicle setup and performance required, keep in mind the longer the gate arm and/or the more preload you place on the gate the less range of movement you have in the gate full open position. Yes you are correct in thinking it's a PIA to reach and adjust when it's installed on the vehicle but it's still doable. I found using a scribe to remove the E-clip was the easiest method but they tend to fly off and are never to be seen again so make sure you have some spares.

Hmm thanks for the input, so what are some signs that would suggest that would need to be adjusted?

 

[KiwiDingo]

Hmm thanks for the input, so what are some signs that would suggest that would need to be adjusted?

There's a fair but involved in getting it to the best position that requires a lot of testing/adjustment while on a dyno to measure and set it at the optimum but for us guys doing it at home you only really need to adjust it if you're experiencing issues/problems. Some issue below;

Slow to build boost, boost drops off at higher rpm or can't adjust boost high enough with manual controller = more gate preload required.
Boost continues to creep up in higher rpm and won't hold steedy, can't adjust boost low enough with manual controller = less gate preload required.

 

[mudgudgeon]

You want some preload on the wastegate spring.

Not enough and it will start to open early with exhaust manifold pressure, and you'll lose boost and delay achieving peak boost

Too much and it won't open soon enough a or will open too slowlynd you might see boost spike above your intended peak boost

You can bench test it with compressed air and a gauge.
If you want peak of 15psi, I'd guess you'd want to see the wastegate start to open around 12psi, and be fully open at 15psi. On the vehicle the wastegate will open sooner because of exhaust pressure.

A boost control valve just delays the boost pressure getting to the waste gate diaphragm by bleeding boost off to the atmosphere, or by adding another spring loaded valve.
They are good to fine tune, but you want to be close with the wastegate setting first.

Pretty sure Gturbo went to an adjustable rate gate actuator where you can swap the springs for different spring rates and different preload.

 

[KiwiDingo]

Pretty sure Gturbo went to an adjustable rate gate actuator where you can swap the springs for different spring rates and different preload.

Negative, Gturbo has never had an adjustable actuator with different springs, they've always been and still are a fully sealed unit. The actuator rod has always been threaded through so you can adjust preload to suit individual needs.

 

[mudgudgeon]

Negative, Gturbo has never had an adjustable actuator with different springs, they've always been and still are a fully sealed unit. The actuator rod has always been threaded through so you can adjust preload to suit individual needs.

I know they were looking at it at some point. Maybe decided against it

 

[Loober]

Thats all good info, I think I'll just run it as is and see how it behaves and go from there.

 

[cruiserpilot]

Thats all good info, I think I'll just run it as is and see how it behaves and go from there.

So have you had any input from the crew at GTurbo?

 

[Lumpskie]

I had the same generation "old" Gturbo on my rig. I asked them:

Hi, My name is Justin and I am the new owner of a 1HD-T powered 80 series in the U.S. My rig is outfitted with an older Grunter turbo and I am currently tuned to 24psi. I am wondering is 24psi safe to run on the older Grunter turbos or is that too much? I have found information on newer Grunters but not older ones. Thanks for your time,

GTurbo's reply:

HI Justin

24psi is fine, we usually have them set to 22psi, but 24 is fine also, they can operate between 14-28psi
The old ones still run as efficiently as the new ones.


My turbo ran great at that boost, but I eventually killed. My opinion is that the stock airbox with that much boost was a bad combo. I have since upgraded to a PDI airbox with a new GTurbo GTX. I love this combo. Torfab now has a reasonable priced airbox that I would consider in your shoes.

 

[Loober]

I got it installed the other day, before I get into first impressions, the following are the stats on the rest of the truck:
1HDFT w/ PDI FMIC, 3" exhaust, and chevy airbox, mild tuning of the stock injection pump.

I was very pleased with the power, feel, EGT's rarely got above 1000 with the stock CT26 running at 15psi until the turbo s*** the bed and I happen to come across the older Gturbo.

So first impressions running the Gturbo set right at 21psi, power diff is pretty much negligible, it does come up to boost quicker, but I don;t notice any advantages with that. Biggest diff is EGT's dropped a good 100 degrees going up the same hill at similar throttle and speed, which was not a problem before but I guess that means I can turn the fuel up more. I don;t think I will as power is more then plenty and I think my fuel millage would suffer. If I paid full pop for what these go for, I'd be disappointed with the lack of ROI compared to the stock CT26.

I think those that feel a huge diff also do not have the other upgrades that I do, and the Gturbo must yield more power then the CT26 in those setups. Biggest upgrade that caused the most diff was the airbox, which really woke the stock CT26, therefore the Gturbo does not seem as a huge of an improvement. Either way ill run it until it dies, meanwhile Ill get the CT26 rebuilt and sitting on the shelf as a spare.

Oh and the Gturbo is much quieter then the CT26 and does not have the same whistle sound, which is kind of a bummer.

Cheers

 

[AussieHJCruza]

I got it installed the other day, before I get into first impressions, the following are the stats on the rest of the truck:
1HDFT w/ PDI FMIC, 3" exhaust, and chevy airbox, mild tuning of the stock injection pump.

I was very pleased with the power, feel, EGT's rarely got above 1000 with the stock CT26 running at 15psi until the turbo s*** the bed and I happen to come across the older Gturbo.

So first impressions running the Gturbo set right at 21psi, power diff is pretty much negligible, it does come up to boost quicker, but I don;t notice any advantages with that. Biggest diff is EGT's dropped a good 100 degrees going up the same hill at similar throttle and speed, which was not a problem before but I guess that means I can turn the fuel up more. I don;t think I will as power is more then plenty and I think my fuel millage would suffer. If I paid full pop for what these go for, I'd be disappointed with the lack of ROI compared to the stock CT26.

I think those that feel a huge diff also do not have the other upgrades that I do, and the Gturbo must yield more power then the CT26 in those setups. Biggest upgrade that caused the most diff was the airbox, which really woke the stock CT26, therefore the Gturbo does not seem as a huge of an improvement. Either way ill run it until it dies, meanwhile Ill get the CT26 rebuilt and sitting on the shelf as a spare.

Oh and the Gturbo is much quieter then the CT26 and does not have the same whistle sound, which is kind of a bummer.

Cheers

You're leaving a lot of performance on the table by increasing boost a reasonable amount and not tuning it accordingly - the best fuel economy I got in my HDJ80 was with a Gturbo red wheel, moonlight airbox, big cooler etc and a fairly aggro tune, it would get in the 12 litres per 100 range which was far better than it ever got stock.
I would say without getting it tuned, you would question the value of a turbo upgrade

 

[Loober]

You got a valid point, Ill play around with the tune see if I can find that sweet spot

 

[KiwiDingo]

So first impressions running the Gturbo set right at 21psi, power diff is pretty much negligible, it does come up to boost quicker, but I don;t notice any advantages with that. Biggest diff is EGT's dropped a good 100 degrees going up the same hill at similar throttle and speed, which was not a problem before but I guess that means I can turn the fuel up more. I don;t think I will as power is more then plenty and I think my fuel millage would suffer.

If you're not turning up the fuel to match the extra boost you'll actually be hurting you're performance. Drop the boost until you're EGT gets back up to previous levels and it'll run better.

 

[SNLC]

We have a Bad Boy red in the works for an FT. Sent the pump off to them, all being set up for 250rwhp.

Should be unbelievable in a 1967 pickup.

Cheers

 

[Loober]

Looks like I am pretty much maxed out on the pump, @SNLC who is doing work on the pump for you?