Sizing a turbo

[landtank]

I've been intriqued about the recent turbo threads and Dusty's build up. Since my truck for now is a winter worrier and on limited duty in the summer I thought I'd look into a turbo build up myself.

So the big thing seems to be picking the right size turbo. I looking at more power but not more headaches. By that I mean that I'd like to keep things were additional changes like injector sizing or adding more of them, piggy back computers and such might be avoided.

Since my fuel pump is the original and my exhaust is junk, that won't really impact the cost as they need to be addressed anyway.

So what Am I looking at for a tubo unit that will have a intercooler?

I found THIS on E-Bay and it seemed to be about the right size from what I can tell.

 

[sportbiker929]

I think that is kinda big

 

[pulse98]

http://www.turboneticsinc.com/turboappdata.htm

http://www.turboneticsinc.com/turboappdata.htm

I have heard that this is a great resource.

 

[clownmidget]

Rick,
Of course it might be easiest to just go with what Dusty ended up obtaining or asking Christo or Steve @ MAF what they ended up using but if you still want to "shop" the options you can start reading up on compressor maps for particular turbos.

Here's a couple of useful links, hope this helps.

some compressor maps (http://64.225.76.178/main.htm)

pretty much the "go to" folks out here in SoCal for high performance stuff (www.turboneticsinc.com/)

 

[CruisinGA]

Read this book.

http://www.amazon.com/Maximum-Boost...0837601606/sr=8-1/qid=1159547140/?tag=ihco-20

 

[landtank]

I think I've earned a PASS on educating myself on this one. I was hoping someone could just give me some guidance. I read through Dusty's build and a link to a sight where he tried to get help on sizing as well.

That site basically said to figure out what you want for HP and then design to it. That's all well and good if you are a performance junky.

What I'm interested in is to put together a system that will add some performance but not break the bank and require a ton of other crap as well.

Basically a Turbo, intercooler, fuel pump, exhaust and maybe a fuel regulator.

Is this even possible?

 

[Rookie2]

I think I've earned a PASS on educating myself on this one.

Basically a Turbo, intercooler, fuel pump, exhaust and maybe a fuel regulator.

Is this even possible?

So why aren't you just copying Dusty's build?

 

[clownmidget]

Garrett T04E, approx .60 to .70 A/R trim
Spearco or APS or PWR intercooler (will edit in Spearco part #)
Toyota Supra TT fuel pump or use the Wallbro equiv.
Go 3" exhaust all the way from the turbo outlet back including a 3" high flow cat like the MagnaFlow/Carsound one
FPR could be a piggyback one like the Bell one or ebay version

 

[informationjunky]

http://www.turbofast.com.au/javacalc.html

 

[landtank]

http://www.turbofast.com.au/javacalc.html

pretty damn cool. I plugged in the numbers and came up with a GT25 and .63AR

I'd follow Dusty's build but I didn't understand most of the turbo stuff.

 

[Dusty]

You are correct Rick in that sizing the Turbo correctly can be difficult. I spent over a week digging through the maximum booste book for answers to this problem. The book is good but it is truly insufficient with regaurds to this topic. The Key is in understanding turbo maps. I now understand these maps and I understand the needs of our motor. I used a to4e 46 trim 70 ar intake w 83 ar exhaust. When you size a turbo there are 3 main cosiderations: the size (46 trim) and the a/r ratios of the compressor/intake (70) and a/r ratio of the turbine/exhaust (83). turbo maps refer to compressors. so much of this is trial and error as Mr bell points out in his book. After spending time on Lextreme.com and after hours comparing turbo maps I came up with the following:
1. T3/t4 hybrid turbos are likely too small on the exhaust side (the t3 side) and will this get too hot although they would likely spool quickly. It would be better to stay with strait t4 turbos
2. A/R exhaust/turbine ratios above 1.0 are likely too large for our aplication.
(I wouldn't get the turbo you posted)
3.We should probably be using compressor/intake a/r ratios greater than .60
4. The turbo trim we should use is probably less than a 60 trim and probably greater than a 40 trim based on compressor maps. In other words I dont realy know what to tell you with regaurd to trim

The way I started was to print out the turbonetic compressor chart and get a general idea and then look at the actual compressor maps for the turbos that looked ok (based on hp and cubic inch parameters from the turbonets chart)

some would argue that the t3/t4 turbo would be great as it would spool faster. But lets assume it spools at only 1300 rpms. Some may argue that they dont need a turbo that is winding up to 5000 rpms anyway and thus the t3/t4 would be great for wheeling. From personal experience I would say that you DO NOT WANT YOUR TURBO SPOOLING WHILE YOU WHEEL! When I was rock crawling some hard stuff in St george utah this past July I had a few occasions where I was slipping and just gassed it as we all do. Well my turbo spools at about 2000 rpms and it is not pleasant when all of a sudden your machine has and extra 50+ hp with an automatic trany when the power is not linear but exponential. Usually I stayed below spool rpms on this trip. The turbo is for the highway/towing/sand/cool factor only. If you want to wheel slowly with more power the supercharger is the answer IMO.

 

[clownmidget]

thanks Dusty, my top of the head guess was at least close to your research

I tried and tried to find the email from Safari where they provided me the actual specs of what their T4E is but had no luck. Mine has been permanently altered though as having it rebuilt here in the states by turbonetics they pointed out that the internals were of a size they couldn't source. they ended up reconfiguring it to the next size up from the aussie guts to what is available here. I guess I have their specs of the finished rebuild somewhere too?

what I noticed from looking at the maps, etc is that the smaller gt25 doesn't move enough cfm of air to feed the larger cylinders of the 1fz.

EDIT: this is the intercooler Photoman used in his custom job for his s/c but it fits very nicely up front.
Spearco Intercooler No. 2-115 (3.5"Dx18.48"Wx6"H)

 

[Dusty]

The more I study the turbo thing the more I conclude that much is just trial and error. Maps and such get you close but you dont know what will happen till you bolt it all together and fire it up.
Mr bells book is great with regards to intercooler selection. basicly Bigger=better. For our application I doubt intercooler design is all that important. Cheep intercoolers will likely work just fine. my intercooler is on ebay for around $130.

I got regected by 2 smog stations yesterday. They opened the hood and said "see ya".

 

[informationjunky]

thanks Dusty, my top of the head guess was at least close to your research

I tried and tried to find the email from Safari where they provided me the actual specs of what their T4E is but had no luck. Mine has been permanently altered though as having it rebuilt here in the states by turbonetics they pointed out that the internals were of a size they couldn't source. they ended up reconfiguring it to the next size up from the aussie guts to what is available here. I guess I have their specs of the finished rebuild somewhere too?

what I noticed from looking at the maps, etc is that the smaller gt25 doesn't move enough cfm of air to feed the larger cylinders of the 1fz.

EDIT: this is the intercooler Photoman used in his custom job for his s/c but it fits very nicely up front.
Spearco Intercooler No. 2-115 (3.5"Dx18.48"Wx6"H)

You might try e-mailing "Arabian Automotive Technologies" they are a user of the safari systems and also the ones who did the custom twin garrets on a 1fz.

 

[SUMOTOY]

Usually I stayed below spool rpms on this trip. The turbo is for the highway/towing/sand/cool factor only. If you want to wheel slowly with more power the supercharger is the answer IMO.

Ok, turbo hat on! (a SC landcruiser guy with a lot of turbo experience = oxymoron?)

Dusty's posts are spot on IMO. Some of the sizing is as much art as science. But to start, Corky Bell's book is a good baseline understanding. Then you need to figure out the airflow of the engine, then how much boost you are shooting for at what rpm, whether you want torque or hp...

Without plugging anything in, going from experience here (exactly half the displacement), I'd say a .63 A/R would be the absolute min in terms of hot side (read: this is your 'torque' monster turbo). On the cold side 60trim would be the biggest I'd go, 50trim probably the lowest. In my engine boost spreadsheets I put 7psi on the 1FZ at around 520cfm.

LT, I'd take one of the existing forum listers 'in use' turbos if you don't want to do a lot of testing. You also want to take a hard look at how exactly you want the truck to be when done. Turbos can be a handful in offroad conditions, and aren't really good for crawling, as Dusty notes.

Having worked with turbos for over 20 years (starting with a tweeked GLH turbo), I personally like the numbers the Eaton M112 (vs TRD M90) puts out. If I was contemplating doing my own boosted truck vs kit, I'd look really hard at that M112, it puts out some pretty impressive numbers, and would suit the 4.5L motor better, probably be easier to fabricate the install, and would rival the best turbo application in terms of torque OR hp.

LT, if you are serious, and get the Corky Bell book, I'm happy to help you offline with some of your calculations, sizing and intercooler stuff. I have moved out the boundaries on many of my shop spreadsheets to accomodate the LC engine, and the engine can be made a monster from the looks of things. Question is: Are you sure that's what you want.

My .o2

SJ

 

[turbocruiser]

Some would argue that the t3/t4 turbo would be great as it would spool faster. But lets assume it spools at only 1300 rpms. Some may argue that they dont need a turbo that is winding up to 5000 rpms anyway and thus the t3/t4 would be great for wheeling. From personal experience I would say that you DO NOT WANT YOUR TURBO SPOOLING WHILE YOU WHEEL! When I was rock crawling some hard stuff in St george utah this past July I had a few occasions where I was slipping and just gassed it as we all do. Well my turbo spools at about 2000 rpms and it is not pleasant when all of a sudden your machine has and extra 50+ hp with an automatic trany when the power is not linear but exponential. Usually I stayed below spool rpms on this trip. The turbo is for the highway/towing/sand/cool factor only. If you want to wheel slowly with more power the supercharger is the answer IMO.

Wow, I was surprised to read this, not arguing at all with Dusty's experience with his setup, and only going on my own experience with my setup, but I find the boost super managable at all times off road; I start spooling at around 800 to 1000 rpm and the power line feels much more linear than "50+ HP all at once". Again, I'm not arguing I'm just saying that the setup, as Dusty asserted, seems to make a major difference on when things start to spool and start to produce power and for how longly (word?) and how linearly they continue to produce that power. Past the science is the art of mixing and matching all the right ratios and sizes and such and that takes a huge committment to try and retry til the magic mixture synthesizes. Dusty gets my maximum respect for throwing the dart right at the sweet spot for a first run, pretty impressive indeed.

Anyways, for whatever mathematical reason, I have never had a single situation where I worried about the turbo offroad - by selecting the right gear and using the right amount of accelerator I have always felt fine under boost. Now one thing I learned little lessons on is dont do the "floor it and hope it helps" method on offroad obstacles - I used to do that all the time on my old 88 4Runner and in many if not most cases it would get me going again - if I did that same thing with the turbo, the rig would rocket off on whatever violent vector all that power takes it - it is a very unsafe and unsettling feeling actually. Other than that no worries with the system offroad; it is always an asset in my opinion.

 

[reffug]

Rather than typing a lengthy diatribe I'm just gonna say that I would concur with Turbo. I have found that after getting to know your system that a Turbo is an asset in all situations, asphalt or offroad.

 

[landtank]

turbocruiser, any info you can share with us on what turbo is in that thing?

 

[reffug]

turbocruiser, any info you can share with us on what turbo is in that thing?

He's got the safari system on that truck Tank. I can't remember how in depth he gets on it but he is a past featured ROTW. Probably some good info there on his total package....

 

[SUMOTOY]

More on turbo sizing

When I looked at doing my own turbo application to my 80 before the SC, the best 'sizing' available for the money is doing a dual turbo setup. What was really easy for me was to think of the 4.5L motor as 2 x 2.226L motors I work on daily......

Audi production turbo engine 1982>1996 = 2226cc (x 2) = 4452cc

Audi turbo stock choices
1982- 1988 = K26 #6 hotside good to ~300hp continuous at 2226cc
1989-1996 = k24 #6 hotside good to ~280hp continuous at 2226cc

Tweeked turbo choices
Various 7200 comp turbos good to 400hp continuous at 2226cc

6 cylinder engines divided into 2 turbo systems give ideal exhaust pulse. Very high engine volumetric efficiency.

K24 and k26 turbos can be had used for a couple hundred bucks each. The k24 on the stock I5 4v head made 227hp and 257lb/ft of torque at 15psi. I could see a 400hp truck with SC type torque.

1FEFZ has really good exhaust manifolds.

Single big turbos are tough to size. You can chase torque or HP, but both would be better served by a dual turbo setup. And LT, Audi has produced almost a million turbo applications on inline-5 motors exactly half the size of ours.

Hmmmmm....

Scott Justusson
QSHIPQ Performance Tuning
Chicago