- Thread starter
- #4,061
My old single turbo had it as well. I completely restricted the line and I still wasn't too happy with the performance. How much would you say it improved your performance?
Builds Big Red Toy (3 Viewers)
- Thread starter The Phoenician
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
If that didn't help then I'd advise tightening the actuator rod as well. With your set up you should be seeing way more safe boost than 20 psi. It may be that part of the discovery is that there is too much fueling happening but from the numbers I know those turbos can work better together so I'm hoping to get those working better together first.
For me I have a little device like that, I've tightened my actuator rod several turns, and am running an extra spring on the wastegate lever to get me more preload to keep the wastegate shut. Truck is currently getting some fixes so it's not running right now but when it is I'll do some numbers for you as a comparison. Mine lights pretty fast and builds boost quickly. At my current fueling I'm hitting 64 psi total boost and am in the 1300-1400F egt range if I let it. Boost and Egt is a little high for my tastes so it's a never ending cycle of tuning for me.
For me I have a little device like that, I've tightened my actuator rod several turns, and am running an extra spring on the wastegate lever to get me more preload to keep the wastegate shut. Truck is currently getting some fixes so it's not running right now but when it is I'll do some numbers for you as a comparison. Mine lights pretty fast and builds boost quickly. At my current fueling I'm hitting 64 psi total boost and am in the 1300-1400F egt range if I let it. Boost and Egt is a little high for my tastes so it's a never ending cycle of tuning for me.
Hojack
♠️Project Snowball❄️
You 2 and your compounds...
Hojack
♠️Project Snowball❄️
Nah... I’m super stoked with my setup
- Thread starter
- #4,066
....Until you feel the potential of more power. This s*** is worse than heroin, you'll see.
- Thread starter
- #4,067
I spotted this beauty when driving up from San Antonio to Austin in the Tacoma.
As I got closer, I realized it has ambulance doors and a diesel engine.
I passed it without realizing who the driver was. About 30 seconds later i get a text from @davegonz saying "nice Tacoma".
I called him and we chatted about his former UN vehicle for a bit. I won't go into details and steal his thunder about it. But He did mention that he won't sell it.
I'm betting it finds a new owner in 18 months, and I have dibs. Just going on record is all.
I'll update the boost numbers on big red shortly.
As I got closer, I realized it has ambulance doors and a diesel engine.
I passed it without realizing who the driver was. About 30 seconds later i get a text from @davegonz saying "nice Tacoma".
I called him and we chatted about his former UN vehicle for a bit. I won't go into details and steal his thunder about it. But He did mention that he won't sell it.
I'm betting it finds a new owner in 18 months, and I have dibs. Just going on record is all.
I'll update the boost numbers on big red shortly.
- Thread starter
- #4,068
Ok, I've been waiting on this all week and I got the boost fooler in the mail this morning.
I screwed it in all the way for a good baseline, then waited for the rain to slow down. I went out and took off the old one without the adjustable screw. To get to it I had to take off the silicone boot.
Put it on and went for a drive.
It's pretty much the same beast until hits 20psi, then it's a whole nother beast on steroids. I even had a little turboed VW try to goat me into racing him.
At first I got it to 30 psi easily in 3rd gear and was excited. I tried again with a little more fuel and it shot up from 15 psi to 45 like it was nothing. With more excitement and courage I gave it a little more and the needle flew passed 60psi. I only let off because my EGTs had hit 1400*. My gauge only goes up to 60PSI, but if I were to guess it could have gone as far as 70 psi, but don't hold me to that. Anyway, here are the numbers my wife managed to take.
It was a rainy day similar to the first time we recorded the numbers, but it was much warmer today at 74*.
Here are the numbers, we were not able to record anything above 30PSI, but will try again at a later time. I think I'm keeping the baseline for now. I like the sound of the turbo when it wakes up.
I screwed it in all the way for a good baseline, then waited for the rain to slow down. I went out and took off the old one without the adjustable screw. To get to it I had to take off the silicone boot.
Put it on and went for a drive.
It's pretty much the same beast until hits 20psi, then it's a whole nother beast on steroids. I even had a little turboed VW try to goat me into racing him.
At first I got it to 30 psi easily in 3rd gear and was excited. I tried again with a little more fuel and it shot up from 15 psi to 45 like it was nothing. With more excitement and courage I gave it a little more and the needle flew passed 60psi. I only let off because my EGTs had hit 1400*. My gauge only goes up to 60PSI, but if I were to guess it could have gone as far as 70 psi, but don't hold me to that. Anyway, here are the numbers my wife managed to take.
It was a rainy day similar to the first time we recorded the numbers, but it was much warmer today at 74*.
Here are the numbers, we were not able to record anything above 30PSI, but will try again at a later time. I think I'm keeping the baseline for now. I like the sound of the turbo when it wakes up.
| Total Boost in PSI | Large Turbo Boost in PSI | Gear/Speed | Outside Temps In Farenheit | Weather | Date | Elevation |
| 10 | 3 | N/A | 74* | Rain | 4/11/2020 | 755' |
| 15 | 4 | |||||
| 30 | 7 | |||||
| 15 | 4 | |||||
| 30 | 7 | |||||
| 11 | 3 | |||||
| 30 | 7 | |||||
| 11 | 3 | |||||
| 30 | 7 | |||||
| 17 | 4 | |||||
| 16 | 4 | |||||
| 20 | 5 | |||||
| 18 | 4 | |||||
| 25 | 6 | |||||
| 15 | 4 | |||||
| 25 | 6 | |||||
| 20 | 5 | |||||
| 18 | 5 | |||||
| 20 | 5 | |||||
| 30 | 7 | |||||
| 15 | 4 |
60 PSI!? That's insane!
Good catching up with you on Friday.
Good catching up with you on Friday.
Last edited:
- Thread starter
- #4,070
- Thread starter
- #4,071
Tried to take a video for proof. Didn't quite go as planned. Luckily it was an easy fix and I still drove home with 7 to 10 psi.
Ah yes, now we're starting to pop boots. The memories are coming back. Here are the results of the numbers with the boost fooler installed and if I understood correctly with it fully shut (allowing no boost signal to the actuator). That mean it is drive pressure working against that internal flap in the exhaust housing that is opening your wastegate.
Pretty much the same until 20 psi and then it looks like it is building better than before. Bummer that your large turbo boost gauge is not next to your total boost. I can see how this is harder to get numbers. I've got my total and large gauges right next to each other. I was watching the video to see if I could map out the results of higher boost.
In attempts to reduce egts I think you can work the small turbo even more, the challenge is now total boost. Can you remind me what exhaust housing size is on your large turbo and if it has its own wastegate?
If the large does have a wastegate I say get the small turbo to work more by adding additional preload to your wastegate actuator (add an external spring or tighten down the rod on the actuator) to keep the small working more before the large gets the additional exhaust flow. Then reduce the preload on the large's actuator to get that to open sooner which will let the exhaust escape and limit total boost and reduce egts.
If the large turbo does not have a wastegate then total boost is reduced by turning down the power screw on the injection pump. Reducing the fueling will also reduce the egts as well. If you have to turn down the fueling I'd still want to make the small turbo to work more.
Depending how you want to chase this if you don't want to turn down the fuel you then are looking at a larger more efficient intercooler and trying to get your intake to suck outside air and not under hood air. This is to help the egts.
@Jason Andrews talked about the use of turbo blankets and manifold wrap to aid in reducing under hood temps. The blankets also have the benefit of helping the turbo's spool quicker since they run off of heat. I've just picked up a pair of blankets to try out once I get my rig back on the road.
| Total Boost | Large | Small |
| 5 | 1 | 3.7 |
| 10 | 3 | 5.7 |
| 15 | 4 | 8.7 |
| 20 | 5 | 11.2 |
| 25 | 6 | 13.3 |
| 30 | 7 | 15.3 |
Pretty much the same until 20 psi and then it looks like it is building better than before. Bummer that your large turbo boost gauge is not next to your total boost. I can see how this is harder to get numbers. I've got my total and large gauges right next to each other. I was watching the video to see if I could map out the results of higher boost.
In attempts to reduce egts I think you can work the small turbo even more, the challenge is now total boost. Can you remind me what exhaust housing size is on your large turbo and if it has its own wastegate?
If the large does have a wastegate I say get the small turbo to work more by adding additional preload to your wastegate actuator (add an external spring or tighten down the rod on the actuator) to keep the small working more before the large gets the additional exhaust flow. Then reduce the preload on the large's actuator to get that to open sooner which will let the exhaust escape and limit total boost and reduce egts.
If the large turbo does not have a wastegate then total boost is reduced by turning down the power screw on the injection pump. Reducing the fueling will also reduce the egts as well. If you have to turn down the fueling I'd still want to make the small turbo to work more.
Depending how you want to chase this if you don't want to turn down the fuel you then are looking at a larger more efficient intercooler and trying to get your intake to suck outside air and not under hood air. This is to help the egts.
@Jason Andrews talked about the use of turbo blankets and manifold wrap to aid in reducing under hood temps. The blankets also have the benefit of helping the turbo's spool quicker since they run off of heat. I've just picked up a pair of blankets to try out once I get my rig back on the road.
First off, congrats on compounds! Tuning them takes some patience.
Do you know what your IP timing is set at? I thought I saw mention of an inline pump so I'm assuming you have a P-pump and not a VE?
In another effort to decrease EGT you can play with advancing the timing as well. I wouldn't necessarily start here, but its a place to look once other things have been dialed in. Advancing the timing will give the fuel more time to burn and can sometimes reduce EGT depending on what its currently set at. The other side of that is that it usually reduces boost, which may help you, OR reducing boost traditionally will make EGT rise, which will be bad. It's an adjust and test drive to record data and changes kinda thing...
Depending on what turbo you had that could have helped or made problems worse. The right size single turbo for an engine should have a properly functioning waste gate or it will definitely hinder performance and have high EGT.
The numbers I saw you posted for a breakdown of total boost vs big turbo boost seem on target to me! Does your big turbo have a functioning wastegate? I think I would keep backing out the boost fooler screw until I saw a reduction in max boost to what you would like to see and then see what EGT looks like. I think you are harvesting most of the energy/power with the smaller turbo and not leaving much for the system to "flow" and creating higher drive pressures. When I had this scenario with my rig it would feel good on the low end but hit a wall when I went WOT.
It is difficult to read the 2 gauges and safely drive at the same time, but if you can get your total boost to a semi-safe 40lbs and see if your large is holding 9-10lb range you know you have things adjusted close to ideal. On my setup I had to utilize a boost fooler on each turbo to get them to operate at the desired pressures.
The amount of EGT drop you can get from pulling air from atop a snorkel or anywhere away from the turbos makes a huge difference.
Do you know what your IP timing is set at? I thought I saw mention of an inline pump so I'm assuming you have a P-pump and not a VE?
In another effort to decrease EGT you can play with advancing the timing as well. I wouldn't necessarily start here, but its a place to look once other things have been dialed in. Advancing the timing will give the fuel more time to burn and can sometimes reduce EGT depending on what its currently set at. The other side of that is that it usually reduces boost, which may help you, OR reducing boost traditionally will make EGT rise, which will be bad. It's an adjust and test drive to record data and changes kinda thing...
Depending on what turbo you had that could have helped or made problems worse. The right size single turbo for an engine should have a properly functioning waste gate or it will definitely hinder performance and have high EGT.
The numbers I saw you posted for a breakdown of total boost vs big turbo boost seem on target to me! Does your big turbo have a functioning wastegate? I think I would keep backing out the boost fooler screw until I saw a reduction in max boost to what you would like to see and then see what EGT looks like. I think you are harvesting most of the energy/power with the smaller turbo and not leaving much for the system to "flow" and creating higher drive pressures. When I had this scenario with my rig it would feel good on the low end but hit a wall when I went WOT.
It is difficult to read the 2 gauges and safely drive at the same time, but if you can get your total boost to a semi-safe 40lbs and see if your large is holding 9-10lb range you know you have things adjusted close to ideal. On my setup I had to utilize a boost fooler on each turbo to get them to operate at the desired pressures.
The amount of EGT drop you can get from pulling air from atop a snorkel or anywhere away from the turbos makes a huge difference.
Last edited:
Boost is best thought of in terms of pressure ratio, PR, when working with compounds. I'm in no way an expert, but figured most of this out on my own and finally got it working how it should. I would think to aim to get your big turbo to have between 10-13lbs when you're at 40 total. Whatever feels best.
Atmospheric Pres + Total Boost
14(sea levelish) + 40psi = 54 / 14 = 3.86 Overall Pressure Ratio
Atmos Pres + big turbo boost
14 + 10lbs = 24psi / 14 = 1.71 Big turbo PR
Overall / Big
3.86 / 1.71 = 2.25 little turbo PR
It's been 2 years since I did all this for mine so if I misspoke on anything above someone please correct me.
Atmospheric Pres + Total Boost
14(sea levelish) + 40psi = 54 / 14 = 3.86 Overall Pressure Ratio
Atmos Pres + big turbo boost
14 + 10lbs = 24psi / 14 = 1.71 Big turbo PR
Overall / Big
3.86 / 1.71 = 2.25 little turbo PR
It's been 2 years since I did all this for mine so if I misspoke on anything above someone please correct me.
Last edited:
With a declared elevation of 755ft the online calculator gave me 14.2 for atmospheric. That's the figure I used in those formulas behind the scenes to get the psi numbers above.
Mike, Jason posted the very formulas I used to get you those boost numbers. You are more than capable of running those formulas to get some numbers to aid you in your tuning. This is the only way to figure out what the little turbo is doing and we convert it back to PSI values since that's a number we are typically used to/see on gauges. As you can see we are both curious if your big turbo has an active wastegate. This plays into the suggestions we'll give.
Mike, Jason posted the very formulas I used to get you those boost numbers. You are more than capable of running those formulas to get some numbers to aid you in your tuning. This is the only way to figure out what the little turbo is doing and we convert it back to PSI values since that's a number we are typically used to/see on gauges. As you can see we are both curious if your big turbo has an active wastegate. This plays into the suggestions we'll give.
- Thread starter
- #4,076
Thank you for all the calculations and help and my apologies for the late responses. Work has me running ragged at the moment as I just took over a new position to combat the spread COVID-19.
The big turbo has a waste gate that seems to be controlled by a spring. It's hard to see, but I'll try to take a good picture of it when I'm back home.
Mike I wonder if you have the crazy carl spring actuator type thing like I put on my 75. It was meant for a compound setup like yours. I just cut and rewelded it to stock mounting. Simple to adjust by tightening or loosing the nut on the spring.
- Thread starter
- #4,079
This is what mine looks like. Sorry, this is the only angle i could take the picture from. I don't see a way to adjust it other than changing the spring, and even then, it's going to be hard to do.
Last edited:
I hate trying to adjust those. It looks like it has a rubber boost reference line from the compressor to the WG actuator? If so I would order up another boost fooler to add in the air hose. Much easier to adjust when the WG is opening on the fly. Being able to tune in the middle of a test drive will also speed up progress of getting things dialed in.
