I am waiting for you to stop in Golden on the way to Steamboat so I can drive yours
I am only aware of two TRD with Intercooler and it belongs to Cory Filmore and the original one that was developed by Cameron Concepts.
Sizing a turbo
- Thread starter landtank
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I am waiting for you to stop in Golden on the way to Steamboat so I can drive yours
I am only aware of two TRD with Intercooler and it belongs to Cory Filmore and the original one that was developed by Cameron Concepts.
That intercooler on the supercharger is slick!
The turbo dyno graphs that Christo posted truly show you why a turbo is better. That HP and Torque curve compared to the measely supercharger stomps it into the ground.
The parasitic drag as the crankshaft speed increases on the supercharger goes up with RPM's. YOu can see the power falling off due to not only this.... but also as the air is becoming more heated and less power results. Alchy/Meth injection may be a crutch. Belt driven superchargers are and always will have parasitic horsepower associated with them.
Turbos are simply converted wasted hot exhaust gases to spin some impellers mounted on a common shaft. The turbine side (hot) will determine many things.... great flow down low with quicker spool (smaller A/R); however have a crippling effect as RPM's climb due to limited flow with expelling the gases.... this example will favor a low/med power range and fall off fast up top. ie .60 A/R
A larger A/R will come on a little later with spooling; however favor great mid/top end. ie 1.01 A/R
A good compromise for numbers sake (for example) is a .83 A/R turbine side which can provide both. Good spool and power throughout the curve.
Compressor wheels (cold side-intake) have similar tradeoffs. The amount of increases in efficiency due to new testing/technology in the past few years blows the doors off of what turbos even 5 years ago can do. Quicker spool, more flow down low and up top... simply due to the length and curve of the vanes on the compressor/turbine wheels. Look at Porsches with the variable vane technology!
Remember these are 4.5 liter engines with cylinder heads that flow great. A single turbo setup for our low revving engines should work fine. Twins simply complicate things with plumbing, control, troubleshooting, more heat in the engine bay, etc.
Building this setup isn't rocket science; however tuning it can be.
The turbo dyno graphs that Christo posted truly show you why a turbo is better. That HP and Torque curve compared to the measely supercharger stomps it into the ground.
The parasitic drag as the crankshaft speed increases on the supercharger goes up with RPM's. YOu can see the power falling off due to not only this.... but also as the air is becoming more heated and less power results. Alchy/Meth injection may be a crutch. Belt driven superchargers are and always will have parasitic horsepower associated with them.
Turbos are simply converted wasted hot exhaust gases to spin some impellers mounted on a common shaft. The turbine side (hot) will determine many things.... great flow down low with quicker spool (smaller A/R); however have a crippling effect as RPM's climb due to limited flow with expelling the gases.... this example will favor a low/med power range and fall off fast up top. ie .60 A/R
A larger A/R will come on a little later with spooling; however favor great mid/top end. ie 1.01 A/R
A good compromise for numbers sake (for example) is a .83 A/R turbine side which can provide both. Good spool and power throughout the curve.
Compressor wheels (cold side-intake) have similar tradeoffs. The amount of increases in efficiency due to new testing/technology in the past few years blows the doors off of what turbos even 5 years ago can do. Quicker spool, more flow down low and up top... simply due to the length and curve of the vanes on the compressor/turbine wheels. Look at Porsches with the variable vane technology!
Remember these are 4.5 liter engines with cylinder heads that flow great. A single turbo setup for our low revving engines should work fine. Twins simply complicate things with plumbing, control, troubleshooting, more heat in the engine bay, etc.
Building this setup isn't rocket science; however tuning it can be.
- Thread starter
- #83
Well when I used the above calculator it called out for a GT25 which Garrett states is sized for a 1.6L - 2.5L engine. That would seem to be about half our displacement.
Garrett does spec it's GT35s for a 4.5L engine.
I'm not a book learning type of guy, just isn't how I learn. That works for some but not for me, I'm more tactile/visual orientated. I typically chew around the edges to get a basic understanding before I get out the hard copy. With the basic understanding I can associate what I'm reading to what I already know which helps with understanding. If you want to help me and others with this that would be appreciated, if not, I'll try to get there on my own.
Ok, *most* calculators use engine displacement. Use a turbo supplier site, or use KKK/Garretts liter/displacement charts, Rick, they use single turbo vs displacement. I won't argue that assuming two is 'better', only that Garrett doesn't in their app chart. When I ran duals last year, I came up with the GT28RS as the best turbo. The 25 will choke at high rpm.
Rick, try a airflow calculator. Find out what your lb/min airflow is at your target boost that's what Garrett Maps are looking for. For low boost applications, you want the turbo to be spinning as fast as possible for the given max Pressure Ratio (= boost pressure + ambient pressure/ambient pressure).
HTH
SJ
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Two things that makes me disagree. The charts that Christo has show a turbo with intercooler and fuel/timing mods vs a SC with no intercooler and no fuel/timing mods. As noted, the measely supercharger is stomped to the ground. What Christos charts show is that the SC has a lot of potential with an intercooler and fuel/timing mods.
Again, this chart isn't a good representation or comparo. What would allow you to make this comparo, is if the boost was the same on the turbo kit (it is), the timing and fuel was the same (it's not) and the intercooler was the same (there isn't one on the SC). I look at a well matched SC to the engine application and boost (7psi) vs a turbo that is not at all well matched to the engine application and boost, and think the straight up comparo will be more even.
Given an integral wastegate turbo, I suspect it's even more in the SC favor.
Agreed. Then again, tuning the SC has a lot of variables that are missing from the turbo equation. Like linear boost profile, and very high compressor efficiency for the low boost application. Tuning the SC means intercooler and fuel, since raising the boost with a pulley won't get you anywhere.
From your posts, I understand you have boost experience gnx7 (read: I like your toy list). Be careful to differentiate between low boost high compression add-on vs high boost low compression applications. Put another way, what boost levels did/are you on the GN or Rx7? A lot higher than 7psi given 11 sec quarters I'd say. This would be a no brainer for a turbo guy at even 14psi. 7 just adds a set of problems and inefficiencies that are tough to overcome, btdt. If you look at the turbo Maps, getting a single turbo to even hit Max compressor efficiency at 7psi is almost impossible. If you are looking for max output at low turbo speeds, you hit surge line very quickly. Quite simply the efficiency egg is very narrow on any single turbo app at 7psi.
And don't forget that Dodge had variable vane IHI turbos in 1990, and Bosch motronic with overboost in 1986, posrche spec's the RS2 (k26based) long vane turbine wheel in 1993. Ball bearings have yielded more than the compressors or turbines IMO, and more size choices too. I personally believe after testing a KKK unit with an extra long snail on the cold side, that will be the future of turbos. As will the integration of ceramics and/or titanium. Faster turbo speeds sooner is the race now IMO, the ball bearings started that.
SJ
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Is this right... "ambient pressure/ambient pressure"? Wouldn't that just = boost pressure + 1?
Edit: After further thinking I'm guessing it's supposed to be Pressure Ratio = (boost pressure + ambient pressure)/ambient pressure?
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How exactly does it show this? Are we now talking about tuning the existing TRD setup or are we now adding a completely new blower to an imaginary intercooler and setup that does not exist?
It is an excellent comparison of what is available right now in real life. Not a figment of someones imagination. How many times do I have to say that.
Until someone does it, this is all web engineering.
And why is the turbo not well matched. Just because it does not fit your criteria? Also, are we also specifying the that TRD chosen blower is correctly matched or not? I am cunfussed.
I have also said time and time again, this kit is not set up to be off-the-line street racer. This was done to make the 80 series be better on-road and under heavy load when climbing hills. I can not understand why you keep on knocking it, but you can only postulate that the SC will be better if tuned, intercooled etc.
I have owned both trucks, driven both in high elevation environments and I am still not convinced that if you spent the money you could get the current TRD setup to perform the same. This is like De-Ja-Vu, but until you can post a dyno chart that shows the number close to the turbo, or better, I am done.
I am waiting for you to stop in Golden on the way to Steamboat so I can drive yours
I am only aware of two TRD with Intercooler and it belongs to Cory Filmore and the original one that was developed by Cameron Concepts.
And air to water to boot! Thanks Christo that pic will be my screen saver for a while.
Steamboat is second week in Feb. You need to come out to the ice and play. A lot of really big turbos get regularly chased down in my jolly green giant with that wheezy turbo imitator.
I guarantee you will also be in with some of the best forced induction nerds in the country Christo. A lot of scarey stuff happens in our late night sessions with a lot of Fat Tire Ales. We can put my blizzacks on your truck to make things more even.
Ball bearing turbos, 30psi, GT 35R's bolted to 2.3L, stand alone efi, full rally spec cars, ECU + fuel mods on the most basic of rides, air lockers, torsens, and I'll even bring a really small turbo attached to 2.1 liters that just rocks at 20psi... You are too close to miss this action dude!
SJ
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Christo, what turbo are you using. What's the boost profile, are you using a boost controller? Unless you are using a custom turbo (with a turbo that has been put on a turbo dyno), I see a lot of compromises to every single turbo application on a 4.5L motor. What is the turbo speed at maximum application pressure? The TRD at 7psi appears to be well matched, tho maxed. I'm quite fine with that, as I have a turbo car to play with at more optimal boost profiles.
I only look at what's been done and why. In the 80 turbo application, it's tough to support a single turbo in terms of *better* performance. Compared to what's out there? It's better than a non intercooled, non fuel adjusted Carb compliant M90 app? Ok, I accept your graphs show that. I just stop short of the turbo conclusion if the M90 hasn't been tested under the same conditions.
Christo, I have a very good baselines of turbos and what they can and can't do. 7psi is just plain tough on a 4.5l motor. I can't find a turbo anywhere that doesn't support that conclusion. Several applications won't even get to 65% compressor efficiency at 7psi (considered the absolute min CE for a given turbo)
Appreciate that. I'm working on it, have been for some time. I just don't see fuel and IC as 'big money' items. I'm well under 2 grand to get where I'm at, and I can totally accept the dyno chart as you've put it forth. I've tested the fuel already, and know that the SC kit runs really lean pretty early, so I'd expect to see what your charts show.
I just find a step missing here. Why you went turbo, when all the stuff that makes it 'better' can be used/applied on the SC. I evaluated all the choices last year, including my own turbo setup. I ditched a single based soley on boost pressure goal. You either can't get it to work hard enough, or you get a smaller one to work too hard and chokes the high end.
I just come to a different conclusion Christo. It's not you, it's my 20years in turbos telling me that 7psi on a large displacement motor is a really tough nut using a stock out of the box turbo. I could chase that for a long time, then look at the M90, and just optimize the 7psi.
Peace
SJ
Volume of air is missing volumetric efficiency of the engine (work output is never always 100% efficient) in the text, it is present in the formula. For a guideline, for the 1FEFZ I used 85VE at max HP and 100% at max torque, with slight roller coaster ramp ups to both maxes starting at 80%. I ran that spreadsheet against a known in mine. It's pretty good, probably a bit too good for a beginner. I'd stick with getting some lb/min at 500rpm increments, then going to the maps with whatever boost you are trying to get.
Correcting his text....
CFM = (rpm * cid * .5 * volumetric efficiency)/1728
HTH
SJ
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GT40-35 is what AVO gave me.
No boost controller. I do not have the maps for the turbo. One thing to remember is that we did not develop this kit. We are only localizing it. We went looking for a turbo supplier, found AVO, bought some units and looked at what was involved to make them work on US trucks. Once we had them installed, we dyno'ed them to get some data. They work, perform better in all aspects, (driveability, fuel mileage and power) than the supercharger alternative currently available. Feedback was given to AVO and we are working towards getting kits that might be able to shipped to customers for DIY install.
I do not have all the technical details on the turbo. I am sure AVO did their homework when the chose the application. We are not a tuning shop, we are a Land Cruiser shop that looks for products for our customers.
Yes, exactly, what is out there? I think I posted the available alternatives on a single dyno chart above.
Is the AVO system the best, maybe not, can it be refined, probably, however we have it in a box, customer comes in, we install, tune and deliver it and the customer is happy. What more do we need? If the customer is a tuner that wants to maximize, sure he can do all he want.
I am sure you do. I do not. I just have a product that works as advertised.
If anything the turbo we have is to big, however until you drive the truck and experience it, you can not tell me it does not work. I really don't care if we are at 50% effeciency of the turbo, the truck drives well, has the power Toyota should have put in it in the first place.
Where are you at? What do you have in terms of extra parts? So we can compare apples to apples when we throw $ figures in.
I just find a step missing here. Why you went turbo, when all the stuff that makes it 'better' can be used/applied on the SC. I evaluated all the choices last year, including my own turbo setup. I ditched a single based soley on boost pressure goal. You either can't get it to work hard enough, or you get a smaller one to work too hard and chokes the high end.
I just come to a different conclusion Christo. It's not you, it's my 20years in turbos telling me that 7psi on a large displacement motor is a really tough nut using a stock out of the box turbo. I could chase that for a long time, then look at the M90, and just optimize the 7psi.
Peace
SJ[/QUOTE]
The GT40 MAPS ( I see 4 off the shelf standard issue 40's) indicate that the turbo is really big Christo. The problem is the hot side needs the exhaust flow to spin that turbo. Below 1.4PR the compressor wheel is spinning below 50k, which is the absolute min for most Garretts. In fact, they don't even show the map below 50krpm. It never reaches 60krpm, and most turbos run most efficienty at 80-100krpm.
It also never sees peak compressor efficiency at 1.5PR. I noticed on your dyno chart that it used a smoothing program. Might be interesting to see that dyno run without it. I suspect you will see some of the indications of surging or choking, or both. I also suspect the reason it starts at 2600, is that the airflow of the engine before that point isn't enough to make stable boost levels off the turbo.
I also suspect the reason the dyno chart is breaking up at the top, is because the turbo is just starting to ramp up, right when you are telling the wastegate to ramp it down. On a really big turbo that's really tough to handle, btdt. A boost controller most likely would help, but the wastegate might not be big enough to handle that kind of regulating bypass dump.
My recommendation for anyone running a turbo kit: Get a boost controller. Nothing fancy, just something fast (again, Profec B is one of my favorites). You want the controller to clamp that wastegate shut for ramp up, something spring pressure doesn't do well, especially with big turbos. Then you want it to quickly control the midrange almost immediately. You should get a much better boost profile this way.
Christo, there is no doubt that a lot of turbos will 'work', btdt. That said, it's at a distinct disadvantage to efficiency when it's turbo speed is at the lowest curve, and the CE is never reached. That's the inherent problem with a large turbo running low boost. If you look at the maps of the turbos vs exhaust velocity, you can see that it's really tough to get the airflow in and out of that engine in a low boost scenario.
Kick that GT40 to 2.2PR, life will get really exciting for the 80 owner! Problem 17psi is a lot of boost for the 80...
SJ
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Rick:
My apologies for moving this a bit far from your target. The good news is, it caused me to brush off my dusty (no relation) files and give this turbo idea another shot... I am missing something here. In reality, unless you are going after a one-off application, just about every Garrrett will either be too big or too small to run 7psi throughout the rev range.
What I haven't done is put forth one of the main reasons I went SC, which I will put forth in a separate thread. After extending a couple spreadsheets out over the last few days, I can come to the mathmatical conclusion that for 7psi, you couldn't match airflow of the 1fefz any better than with the M90.
Can fuel, intercooler, etc help? Sure. But strictly on airflow rpm and volumetric efficiency, TRD has to be laughing their respective butts off, the SC hits the mark with a 3.2" SC pulley out of the box.
More to follow, but I can say if you are going after low boost applications, the SC has the advantage for now. In the meantime Rick, I'll stick around this thread, hoping to help the turbo education a bit, recognizing a wide lattitude of tolerance to my modus....
SJ
My apologies for moving this a bit far from your target. The good news is, it caused me to brush off my dusty (no relation) files and give this turbo idea another shot... I am missing something here. In reality, unless you are going after a one-off application, just about every Garrrett will either be too big or too small to run 7psi throughout the rev range.
What I haven't done is put forth one of the main reasons I went SC, which I will put forth in a separate thread. After extending a couple spreadsheets out over the last few days, I can come to the mathmatical conclusion that for 7psi, you couldn't match airflow of the 1fefz any better than with the M90.
Can fuel, intercooler, etc help? Sure. But strictly on airflow rpm and volumetric efficiency, TRD has to be laughing their respective butts off, the SC hits the mark with a 3.2" SC pulley out of the box.
More to follow, but I can say if you are going after low boost applications, the SC has the advantage for now. In the meantime Rick, I'll stick around this thread, hoping to help the turbo education a bit, recognizing a wide lattitude of tolerance to my modus....
SJ
I will try and get the maps from AVO.
Yes, the smoothing was turned on, but it was turned on for all the plots. These were halfway through the tuning.
I already covered this in another thread and explained the downshifting issue. This truck was worse since it had 37" tires on it.
A boost controller might be better in this case, but for the client and what he intends to do with the truck, simpler is better.
Yes, 17psi is a lot, but it could be fun.
- Thread starter
- #96
Just to be clear, I'm not 100% committed to the project as of now. I'm just in the design area to get an idea of what the cost would be and what's available. My truck will never see a SC. 1. there is or will be a york compressor in the way and 2. I don't want to deal with the heat issues.
As of right now I need to get my head around the math of this thing. I did find a company that will build a GT35R with a t04 flange that has a .84AR on the turbine side and will mate several compressors to that for just under $1200.00. Not really the BUDGET choice but I figure that I'll start at the top and work down.
I'm not saying this is the best turbo, just the one I last saw. I'm focussed on the t04 flange as that is the flange used on the cheapo manifilod on ebay.
As of right now I need to get my head around the math of this thing. I did find a company that will build a GT35R with a t04 flange that has a .84AR on the turbine side and will mate several compressors to that for just under $1200.00. Not really the BUDGET choice but I figure that I'll start at the top and work down.
I'm not saying this is the best turbo, just the one I last saw. I'm focussed on the t04 flange as that is the flange used on the cheapo manifilod on ebay.
Give the turbo boys your cfm demands Rick. Remember too, without a turbo dyno, this is a turbo builders 'best guess'. The GT35 turgine will start to choke on the 1FE exhaust below 3500rpm by my calculations (That turbine shows max displacement at 3.2L). It has the potential to be a decent torque generator tho. I also believe that turbo application will be really hard to control with an integral wastegate. Does the manifold you are looking at have a external or internal gate?
Good luck, welcome to the slippery slope and black magic of turbo applications!
SJ
- Thread starter
- #98
that turbo requires an external gate and the manifold has a 38mm tial port
- Thread starter
- #99
Garrett agrees with you on this as well. But the GT35R is a whole different animal and rated for 4.5L
Other good places to call, spec out a turbo, and order one with excellent customer service:
ForcedInductions.com- Alabama ask for Jose
Precision Turbo & Engine- Indiana ask for Dan
Limit Engineering- Arizona ask for Chopper
Turbonetics- CA
Innovative Turbo- CA
Sumo-
I am used to 8:1 compression 3.8 liter GN turbo engines (300-700hp) and 4.1 to 4.5 liter Stage2 Buick race engines (1000hp+). We run 14psi on 91 octane and 20psi+ on 116 octane. A 9:1 engine isn't considered high compression by any means. It will spool a turbo faster though and won't need as much boost as an 8:1 motor to make the same power.
With 4.5 liters of displacement (which is a lot) and a forced induction friendly 9:1 compression it should spool most properly sized turbos quickly. Finding a small turbo that will spool under 2,000rpm will choke the top end unless they are sequentially setup like on the RX-7's and Supra's.
ForcedInductions.com- Alabama ask for Jose
Precision Turbo & Engine- Indiana ask for Dan
Limit Engineering- Arizona ask for Chopper
Turbonetics- CA
Innovative Turbo- CA
Sumo-
I am used to 8:1 compression 3.8 liter GN turbo engines (300-700hp) and 4.1 to 4.5 liter Stage2 Buick race engines (1000hp+). We run 14psi on 91 octane and 20psi+ on 116 octane. A 9:1 engine isn't considered high compression by any means. It will spool a turbo faster though and won't need as much boost as an 8:1 motor to make the same power.
With 4.5 liters of displacement (which is a lot) and a forced induction friendly 9:1 compression it should spool most properly sized turbos quickly. Finding a small turbo that will spool under 2,000rpm will choke the top end unless they are sequentially setup like on the RX-7's and Supra's.