Background: Almost a year ago I started running a 7MGTE/1HD-T hybrid CT26 on my 1HD-T. This is a well-documented swap that makes similar low end boost to the stock setup but it capable of flowing a lot more air up top. The stock turbo is fine at stock boost levels but if you want to increase it to 15psi or higher it just can't maintain the boost at higher rpms. This was a big problem for me on long, steep highway hills where I'd be going back and forth between 3rd and 4th gear (auto). If I got to 3000rpm or higher the boost would start to drop off and the EGTs would rise to an unacceptable level. Swapping in the 7M hybrid largely solved that problem because it was able to maintain 18psi right up to about 3800rpm (the highest I've ever taken it). However, there was still something missing. Both the stocker and the 7M hybrid were slow to build boost off the bottom. Sure, I could throw excessive fuel at it in an attempt to get the exhaust energy up quickly but when your vehicle is a daily driver and you commute in rush hour traffic it's not really all that civilized to be firing off a massive plume of smoke every single time you start moving. So tuning was always a challenge - a constant balancing act between getting good performance and being a good citizen. The other difficulty was that the 7M hybrid couldn't make my desired max boost of 18psi until I was at about 2000rpm. That's fine but on the highway going between 3rd and 4th I would often be below that rpm and below max boost so the EGTs would be getting dangerous. I did everything possible with the stock aneroid rod without grinding a new profile. Still, not perfect.
Flash Forward: In talking to my friend Graeme in Australia some time last year (Mud member gbentink) I had been expressing my frustrations about tuning this thing at high boost (at the time that was 18psi). I knew he had some ideas about how to improve upon the available turbo upgrade options for my truck and I was kind of surprised and disappointed when he stopped posting several months ago. Then, out of nowhere, he resurfaced with some serious news. I'm sure most of you have read this thread and I completely understand why people would be skeptical about the claims made. I've read so much of what Graeme has written that I really wasn't all that shy about putting my money down to be one of the first people to test this turbo upgrade option. I sent off my old stock turbo and a couple of weeks later a package arrived with the new unit all ready for installation..........
I took a lot of photos, measurements, and made a number of observations about the new turbo. I will share none of them.
I respect the fact that someone put a lot of work into developing this and if he ever chooses to divulge any information that's up to him. If not, you can buck up and buy your own if you want to try to figure out what he's done.
What I will do is share my results.
Firstly, I had done the 7M swap exactly a year earlier so this swap was dead simple. It still takes most of a day and it's worth taking your time to make sure you don't miss something. It's a fairly easy job, which is made easier if you've already had every nut and bolt loosened in the past.
I was excited about the first test drive and decided not to touch the manual boost controller (which I had set at 20psi on the old turbo). I also didn't touch the fuel settings.
My first observation was one of confusion. Backing out of my driveway, I saw 3psi. ??? I never made ANY boost in my 20' long driveway with a 90 degree turn at the end before. I wasn't even stepping on it! I did my best to keep it on level ground for a few minutes to let things warm up slowly for the first time. Immediately, I noticed that it just wanted to build boost. The minute I hit the first hill I started smiling and I don't think it went away for about 3 days. Scratch that, it's been a week and a half and I am just thrilled about driving my truck.
The old turbo built boost slowly up to about 7psi, at which point it built faster up to my max of 20psi (it was 18 but I bumped the boost controller up a couple of months ago). The new one built boost at a reasonable pace up to 5psi, at which point the needle rocketed over to 26psi and stayed there. Like, seriously?? The response was nothing short of incredible! I've been noticing that I'm using a lot less accelerator peddle to get moving, the boost is anywhere between 2-6psi higher under ALL conditions, and it just doesn't feel like it's working hard at all. Graeme told me that I would need to adjust the boost controller because this one would be several psi higher. Yeah, no kidding! It seemed quite comfortable at 26 but I decided fairly quickly that I should limit it to about 22 for a while and get it all tuned at that level. I haven't really put in the time to do that yet but this thing doesn't seem to care.
Some Numbers:
Here are a few comparison numbers of my boost levels with the 7M hybrid turbo compared to Graeme's upgrade. Hopefully this actually looks like a chart when I hit the post button.....
Edit: It doesn't. So, the first column is the rpm, second is the boost with the 7M hybrid, third is boost with Graeme's upgrade...
RPM 7M Hybrid Upgrade
1400 5 10
1500 10 15
1600 15 20
1800 18 23
2000 20 26
2200 20 26
3500 20 26
3800 17 23
In both cases, I was at max boost at 2000rpm, but with the 7M turbo that was 20psi and with the upgrade it was 26psi! If I was only looking for 20 I would have been at max at 1600rpm rather than the old 2000. I haven't included numbers between 2200-3600rpm because it's flat through there. At about 3600rpm both turbos start to reach their flow limits at the boost levels I was running. It's important to note that since I adjusted the boost controller to 22psi Graeme's upgrade can flow that much right to 3800, which is the highest I have tested. The 7M turbo would be down to 17psi at that rpm.
Keep in mind that none of these can be taken as absolute maximum numbers. They are very useful as relative comparisons. My main problem is that I'm driving an automatic transmission in city traffic and I simply can't test anything properly. I have to wait till the torque converter locks up (70km/h in 3rd or 4th with Rodney's valve body) because everything with the TC unlocked is meaningless. What I'm unable to do is floor it in 4th below 2000rpm because it will downshift and I can't prevent it. All I can do is try to get close to the downshift point without actually reaching it. My tests are fairly well controlled but based on city driving with a known amount of peddle on known hills. Pseudo-scientific at best.
On the Easter weekend I'll be heading off on my first fishing trip of the year and will be doing a good long nasty hilly highway drive. That will give me way more information.
For now, all I can say is that this upgrade is absolutely incredible. I keep adding more fuel and the truck gets faster and faster but is still burning clean (except for the puff off the line, which is difficult to avoid). I'm actually scared to do a brake stand launch now because I'll be at 22psi and I may actually break something.
Low end boost: effortless
Transient response: fast and effortless
High end flow: better than any previous high flow options
Honestly, I thought the only way to get this kind of turbo response on my truck was going to be exploring a VNT. How wrong I was.....
I'll update with a bit more solid information after Easter.
And just in case you missed it, read it here
Flash Forward: In talking to my friend Graeme in Australia some time last year (Mud member gbentink) I had been expressing my frustrations about tuning this thing at high boost (at the time that was 18psi). I knew he had some ideas about how to improve upon the available turbo upgrade options for my truck and I was kind of surprised and disappointed when he stopped posting several months ago. Then, out of nowhere, he resurfaced with some serious news. I'm sure most of you have read this thread and I completely understand why people would be skeptical about the claims made. I've read so much of what Graeme has written that I really wasn't all that shy about putting my money down to be one of the first people to test this turbo upgrade option. I sent off my old stock turbo and a couple of weeks later a package arrived with the new unit all ready for installation..........
I took a lot of photos, measurements, and made a number of observations about the new turbo. I will share none of them.
I respect the fact that someone put a lot of work into developing this and if he ever chooses to divulge any information that's up to him. If not, you can buck up and buy your own if you want to try to figure out what he's done. What I will do is share my results.
Firstly, I had done the 7M swap exactly a year earlier so this swap was dead simple. It still takes most of a day and it's worth taking your time to make sure you don't miss something. It's a fairly easy job, which is made easier if you've already had every nut and bolt loosened in the past.
I was excited about the first test drive and decided not to touch the manual boost controller (which I had set at 20psi on the old turbo). I also didn't touch the fuel settings.
My first observation was one of confusion. Backing out of my driveway, I saw 3psi. ??? I never made ANY boost in my 20' long driveway with a 90 degree turn at the end before. I wasn't even stepping on it! I did my best to keep it on level ground for a few minutes to let things warm up slowly for the first time. Immediately, I noticed that it just wanted to build boost. The minute I hit the first hill I started smiling and I don't think it went away for about 3 days.
Scratch that, it's been a week and a half and I am just thrilled about driving my truck. The old turbo built boost slowly up to about 7psi, at which point it built faster up to my max of 20psi (it was 18 but I bumped the boost controller up a couple of months ago). The new one built boost at a reasonable pace up to 5psi, at which point the needle rocketed over to 26psi and stayed there. Like, seriously?? The response was nothing short of incredible! I've been noticing that I'm using a lot less accelerator peddle to get moving, the boost is anywhere between 2-6psi higher under ALL conditions, and it just doesn't feel like it's working hard at all. Graeme told me that I would need to adjust the boost controller because this one would be several psi higher. Yeah, no kidding! It seemed quite comfortable at 26 but I decided fairly quickly that I should limit it to about 22 for a while and get it all tuned at that level. I haven't really put in the time to do that yet but this thing doesn't seem to care.
Some Numbers:
Here are a few comparison numbers of my boost levels with the 7M hybrid turbo compared to Graeme's upgrade. Hopefully this actually looks like a chart when I hit the post button.....
Edit: It doesn't. So, the first column is the rpm, second is the boost with the 7M hybrid, third is boost with Graeme's upgrade...
RPM 7M Hybrid Upgrade
1400 5 10
1500 10 15
1600 15 20
1800 18 23
2000 20 26
2200 20 26
3500 20 26
3800 17 23
In both cases, I was at max boost at 2000rpm, but with the 7M turbo that was 20psi and with the upgrade it was 26psi! If I was only looking for 20 I would have been at max at 1600rpm rather than the old 2000. I haven't included numbers between 2200-3600rpm because it's flat through there. At about 3600rpm both turbos start to reach their flow limits at the boost levels I was running. It's important to note that since I adjusted the boost controller to 22psi Graeme's upgrade can flow that much right to 3800, which is the highest I have tested. The 7M turbo would be down to 17psi at that rpm.
Keep in mind that none of these can be taken as absolute maximum numbers. They are very useful as relative comparisons. My main problem is that I'm driving an automatic transmission in city traffic and I simply can't test anything properly. I have to wait till the torque converter locks up (70km/h in 3rd or 4th with Rodney's valve body) because everything with the TC unlocked is meaningless. What I'm unable to do is floor it in 4th below 2000rpm because it will downshift and I can't prevent it. All I can do is try to get close to the downshift point without actually reaching it. My tests are fairly well controlled but based on city driving with a known amount of peddle on known hills. Pseudo-scientific at best.
On the Easter weekend I'll be heading off on my first fishing trip of the year and will be doing a good long nasty hilly highway drive. That will give me way more information.
For now, all I can say is that this upgrade is absolutely incredible. I keep adding more fuel and the truck gets faster and faster but is still burning clean (except for the puff off the line, which is difficult to avoid). I'm actually scared to do a brake stand launch now because I'll be at 22psi and I may actually break something.
Low end boost: effortless
Transient response: fast and effortless
High end flow: better than any previous high flow options
Honestly, I thought the only way to get this kind of turbo response on my truck was going to be exploring a VNT. How wrong I was.....
I'll update with a bit more solid information after Easter.
And just in case you missed it, read it here
