VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: 0 Xero 0 on March 29, 2013, 10:52:14 pm
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Hey, everyone, this is my first post here. I hope to acquire a vw caddy or rabbit in the near future and I've already researched and read a lot of threads and info on modifying these engines. I've gone to great lengths to plan out (what I hope will be) my future build. I'd like anywhere from 150-200 whp. I've done a lot of research into which turbo will work best for my application. I've plotted out where the engine would make peak horsepower and I've calculated that at 30 PSIG, I'll be at roughly 76 percent compressor efficiency with a pressure ratio of 2.7. That is as good as you can get as far as I'm concerned. Ideally the combustion events will be on the leaner side so that smoke (wasted fuel) and EGTs are minimal. Here is a site that has the map for this turbo and many other turbos I think a lot of you would find useful.
http://www.stealth316.com/2-3s-compflowmaps.htm (http://www.stealth316.com/2-3s-compflowmaps.htm)
Here is the site that has the measurements for the wheels and housings.
http://www.stealth316.com/2-turboguide.htm (http://www.stealth316.com/2-turboguide.htm)
I've checked this map against many Garrett and IHI turbos, but the MHIs come out on top. The closest turbos I've found to this one are the TD04-16T and TD05-14G. The main differences between these are the compressor wheels, but the TD05 has a bigger turbine too. Oddly enough, the TD04-18T still outflows both turbos in most regards. I don't know if the two percent will make a huge difference in overall engine efficiency or if it would be better to get the TD04-16T for better spool-up times.
Have any of you run any MHI turbos with any marked success?
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I take it you want to do custom manifolds and downpipes? I haven't heard of anyone using mitsu turbos but I think it's probably because of the flange incompatibility more than anything, too much work for a junkyard turbo.
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I don't mind fabricating the exhaust system. I want a 2.5" exhaust anyways. The other MHI turbos that are closest in efficiency are 74 percent efficient. That's awesome too and is stilling better than any others I've looked at. I want the engine to perform optimally and run a little lean with an AFR of 20:1 if possible and these turbos will allow that.
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Don't the Volvo guys run those? The numbers sound familiar.
Not sure how apples to oranges it might be, but they may be able to offer some
hands on experience with them. turbobricks forum is good
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Yeah, guys use em on volvos and saabs frequently. The problem is gas engines rarely run a pressure ratio over 2.0 and their experiences wouldn't correlate well to a diesel application. Hasn't anybody tried to make an adaptor for the exhaust flange for these so the stocks manifold would work? I'll probably try that first assuming I get a caddy soon.
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Here's an adapter with a good design:
http://item.mobileweb.ebay.com/viewitem?itemId=140900971201
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Rabbit Jockey could chime in if he is interested on the map portion.
The adapter could be done like that or you could use a flange fitting the VW manifold welded to pipe welded to a flange matching your turbo. Then it could be clocked and turned however you wanted. If you wanted.
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Yeah, I like the direct flange adapter idea personally. It's simpler. I'd also like to use a diverter valve like the one BD diesel makes for light duty trucks. Has anyone done that on these engines?
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Here's my plot on the compressor map. I'm sure it's slightly off because I had to guess a little for my boost (and P/R by extension) at the lower end of the map, so that is probably wrong, but I think most of it is correct. The parameters I'm going by are these:
- Max Boost - 30
- Atmospheric Pressure - 11.47 PSI or 23.35 in Hg
- VE - 90% (this may be off; however, this seems like a feasible number with a ported head and exhaust manifold)
- Compressor Efficiency - 76% (in this case)
- BSFC - 0.409 @ 20:1 AFR; 0.372 @ 22:1 AFR (again, I'm making an assumption based on what I've read)
(http://i462.photobucket.com/albums/qq345/zero716/td04h-18t-cfmplot_zps188d40a2.jpg)
The main differences between the MHI turbos are wheel sizes and housing sizes. The TD04s have 6 cm^2 turbine housings or 0.41 A/R and the letters after the frame size (04, 05, 06, etc.) correspond to the turbine wheel. I'm assuming my turbo has the TD04L 76 trim (41 mm/47 mm) or TD04H 73 trim (44 mm/52 mm) turbine. The number after the frame size (15G, 16T, 18T, etc.) designates the compressor wheel size and the letter is the wheel style. For the 18T, the measurements are 45 mm/56 mm and the T means the blades are all the same height. A G-style wheel has half of the blades shorter than the rest.
I'm sure some of you are better at this than me, so if I made any mistakes, feel free to correct me. I used Garrett's equations for a lot of this and tinkered with some turbo calculators I felt were decent for a diesel.
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Here's my plot on the compressor map. I'm sure it's slightly off because I had to guess a little for my boost (and P/R by extension) at the lower end of the map, so that is probably wrong, but I think most of it is correct. The parameters I'm going by are these:
yes but 30 psi would be nearly 3bar on the map
- Atmospheric Pressure - 11.47 PSI or 23.35 in Hg
i think you just mis typed this? should be 14.7psi
- VE - 90% (this may be off; however, this seems like a feasible number with a ported head and exhaust manifold)
I usually use 85 when considering a ported head, but that is very optimistic
- Compressor Efficiency - 76% (in this case)
- BSFC - 0.409 @ 20:1 AFR; 0.372 @ 22:1 AFR (again, I'm making an assumption based on what I've read)
i usually use a bsfc of .36-.38 and afr of 18:1 but they are all guesses, i just base all my numbers off of comparing dynos to the engine specs of the car.
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The main differences between the MHI turbos are wheel sizes and housing sizes. The TD04s have 6 cm^2 turbine housings or 0.41 A/R and the letters after the frame size (04, 05, 06, etc.) correspond to the turbine wheel. I'm assuming my turbo has the TD04L 76 trim (41 mm/47 mm) or TD04H 73 trim (44 mm/52 mm) turbine. The number after the frame size (15G, 16T, 18T, etc.) designates the compressor wheel size and the letter is the wheel style. For the 18T, the measurements are 45 mm/56 mm and the T means the blades are all the same height. A G-style wheel has half of the blades shorter than the rest.
I'm sure some of you are better at this than me, so if I made any mistakes, feel free to correct me. I used Garrett's equations for a lot of this and tinkered with some turbo calculators I felt were decent for a diesel.
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this is how i would map it for 200 crank horsepower
(http://www.squirrelpf.com/turbocalc/graph.php?version=4&pr0=1&pr1=1.07&pr2=1.86&pr3=2.66&pr4=2.66&pr5=2.66&pr6=2.66&pr7=2.66&airflow0=0.011&airflow1=0.015&airflow2=0.045&airflow3=0.09&airflow4=0.12&airflow5=0.148&airflow6=0.159&airflow7=0.166&product_id=84)
http://www.squirrelpf.com/turbocalc/index.php?version=4&target_peak_power=200&pr_ref=14.7&engine_disp=1.6&engine_disp_factor=0&target_af=18&bfsc=0.36&max_ic_loss=1&rpm_redline=6000&rpm_peak_power=5250&rpm_max_boost=3200&rpm_min_boost=1250&vol_1=80&vol_2=80&vol_3=80&vol_4=80&vol_1=80&vol_2=80&vol_3=80&vol_4=80&intake_temp_1=90&intake_temp_2=120&intake_temp_3=105&intake_temp_4=130&turbo_n=1&map_sel0=84 (http://www.squirrelpf.com/turbocalc/index.php?version=4&target_peak_power=200&pr_ref=14.7&engine_disp=1.6&engine_disp_factor=0&target_af=18&bfsc=0.36&max_ic_loss=1&rpm_redline=6000&rpm_peak_power=5250&rpm_max_boost=3200&rpm_min_boost=1250&vol_1=80&vol_2=80&vol_3=80&vol_4=80&vol_1=80&vol_2=80&vol_3=80&vol_4=80&intake_temp_1=90&intake_temp_2=120&intake_temp_3=105&intake_temp_4=130&turbo_n=1&map_sel0=84)
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I used a P/R of 2.7 and an atmospheric pressure of 11.47 because the elevation is 6800 feet where I live. I'll re-run my data, but I don't like the squirrel performance calculator. Most calculators are catered toward gas engines that run around 10-12:1 within P/Rs.
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I used a P/R of 2.7 and an atmospheric pressure of 11.47 because the elevation is 6800 feet where I live. I'll re-run my data, but I don't like the squirrel performance calculator. Most calculators are catered toward gas engines that run around 10-12:1 within P/Rs.
If there was only a spot in your profile to put your location...oh wait there is.
That kind of thing helps others. In this case Trev could have at least had a clue that you were no where near sea level.
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I used a P/R of 2.7 and an atmospheric pressure of 11.47 because the elevation is 6800 feet where I live. I'll re-run my data, but I don't like the squirrel performance calculator. Most calculators are catered toward gas engines that run around 10-12:1 within P/Rs.
I don't really see anything on the Squirrel calculator that is in any way catered to the fuel type of the engine, other than the default AFR / BSFC numbers that are on there? Just curious what you don't like about it.
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ok i understand, that makes a big difference. also the numbers on the y axis are not a definite pressure, they are a ratio so at 11.47 psi atmospheric pressure and 30 psi of boost, it would put you around 3.6 on the y axis. i hope that helps
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11.47 psi atmospheric pressure and 30 psi of boost, it would put you around 3.6 on the y axis. i hope that helps
I got closer to 3.9 when I ran the numbers. Pretty much 1 or more higher than you want to be for that, or most turbos..
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I'm sorry about the location part of my profile. I thought it would prompt me to enter that when I registered and forgot about it. Regarding the squirrel performance calculator, it just seems really off to me whenever I plotted any points in. It doesn't seem to like the AFRs that diesels run. I literally went through every map that calculator has and none of them worked. Granted, I have my ideal AFR set leaner than what most people probably run on theirs, but if the turbo is sized properly for a given application, the engine should run lean and have minimal smoke output. I don't like the calculator because I calculated these equations for plotting compressor map points by hand and I trust my brain and the equations more than the calculator. I'll have to re-run my calculations with a VE of 85 percent and a lower BSFC and see what happens.
RabbitJockey, you're definitely right about the P/R. I goofed on that. After going through all the calculations again, I came up with a MAP of 55.11 PSIA, which equates to 43.64 PSIG and a P/R of 3.8 with an AFR of 20:1. I've looked through some builds, and, as far as I know, no one has used that much boost on these engines. With an AFR of 18:1, I came up with 38 PSIG and a P/R of 3.3. That's still pretty high on most maps. I'm wracking my brain trying to figure out why this seems so difficult because there are people who've made 200 whp on these engines. Perhaps they have a lot more fuel than I'm accounting for. Here are the equations I used from Garrett's site:
http://www.turbobygarrett.com/turbobygarrett/choosing_turbo
Here are my calculations:
Wa = HP x AFR x (BSFC/60)
Wa = 200 x 20 x (0.372/60) = 24.8 lbs/min
MAP = (Wa x R x (460 + T)) / (VE x (N/2) x Vd)
MAP = (24.8 x 639.6 x (460 + 130)) / (0.85 x (4500/2) x 97.6) = 50.14 PSIA - 11.47 PSI = 38.67 PSIG, P/R 3.4
As you can see, lowering the AFR results in a lower Wa, which decreases the MAP and required boost. I would rather not run richer than 18:1 and ideally stay around 20:1 to maximize combustion efficiency. This is obnoxious because it seems like the only way to get near 20:1 is through the use of compound turbos, which I'm not averse to, but I'd prefer to stay with a single. A VGT could help here, but they have reliability issues compared to their fixed geometry brethren. Does anyone know a turbo I can use that will work here?
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So just curious.. why do you want to run 30+ psi??
What exactly are you using this setup in and for?
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I think at your altitude unless you run compounds 200hp isn't going to happen. I would sweat the air fuel ratios too much. On diesels it doesn't matter that much so long as all your tenps are ok. I came up with 18:1 just cause it made all the numbers work with dynos I'd seen. I'm no scientist it could be off haha
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Ultimately, yes. All the temps in check will be fine regardless of exhaust smoke opacity.
Isn't 200hp out of a 1.6 like REALLY pushing it anyways? lol
I swear I have read of diesel builds running close to like 14 AFR. Pretty sure it is a number that need not be worried about as it is in a gas engine. The fuel will burn no matter how lean or rich, if you keep the EGT's in check it will be producing maximum power as it can. If you holf back fueling so much that you run a 20:1 AFR then I don't think you will ever make it the power goals you desire. Gotta have fuel fuel and more fuel to make the powers.
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I think at your altitude unless you run compounds 200hp isn't going to happen. I would sweat the air fuel ratios too much. On diesels it doesn't matter that much so long as all your tenps are ok. I came up with 18:1 just cause it made all the numbers work with dynos I'd seen. I'm no scientist it could be off haha
Yeah, I think compounds is the only way to unless I did some trickery with a VGT like a HE351 and used a diverter valve on it. That turbo probably wouldn't fit very well between the firewall and the engine in a caddy or rabbit though, haha! The air fuel ratio isn't a variable that can easily be controlled; however, when you're using equations to find a turbo to suit your needs, it is useful because you should ideally be able to find an efficient match. An AFR of 18:1 actually isn't that bad, I just hate seeing people driving diesels around belching smoke everywhere and kids asking how to make smoke because they all equate smoke with power, which isn't true. Yes, a rich engine will make more power than a lean-burn engine, but ideally, they are run lean. Jeff Garmon has compounds on a 12-valve cummins that makes 700 rwhp and it only puts out a light haze at the exhaust pipe.
Ultimately, yes. All the temps in check will be fine regardless of exhaust smoke opacity.
Isn't 200hp out of a 1.6 like REALLY pushing it anyways? lol
I swear I have read of diesel builds running close to like 14 AFR. Pretty sure it is a number that need not be worried about as it is in a gas engine. The fuel will burn no matter how lean or rich, if you keep the EGT's in check it will be producing maximum power as it can. If you holf back fueling so much that you run a 20:1 AFR then I don't think you will ever make it the power goals you desire. Gotta have fuel fuel and more fuel to make the powers.
I was using 200 hp as a benchmark more than a goal really. I'd probably be content with 150-175 hp or so, but I won't know until I'm actually driving the vehicle or not. Yes, you can run any AFR you want. Most sled pullers and diesel drag trucks have AFRs from 14-16:1 but that's because heat is what powers a turbo. The top tier classes have guys running huge turbos that are usually more suited for a low pressure turbo in a compound setup, so they throw as much fuel at those engines as they can because it helps spool the turbos and more fuel always equals more power.
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nah those turbos are too big and the high altitude makes them even worse for you. vnt can't make up for a surging compressor map, it would only make it worse. i just don't think theres going to be a turbo that will work at your altitude on a 1.6 to make 150-175hp with out being in compound.