Turbo choices
 

I know a little about turbos, not enough to really make an unassisted decision, though.

1.6L Diesel, never rev it over 4k (no tachometer yet), would like better efficiency and a bit more torque.

Right now, its turned down so that there is no smoke at full pedal with enough load to slow the car down. I don't like smoke...

Anyway, just wanted suggestions for a turbo based on those criteria. K03, T25 seem to be in the right range. I don't really want to boost more than, say, 15psi, but would like it to start spooling off idle.

If you are starting with a normally aspirated engine, they don't last too well above the normal EGTs. The turbo VW engines had better oil passages and what not. So when you put the turbo on Don't turn the fuel up much from where you are at now.

If you go to Garrett Turbo's website, they have all the formulas to make a proper sizing choice. Click on the Diesel button and go to town.

The 90-96 twin turbo Nissan 300 ZX may be a source of a decent turbo for your application. Get em used off a junker motor.

regards
Mech

From speaking with tuners who specialize in Dubs, the only difference in the block is the presence of piston oil squirters, and the injection pump had a boost enrichmernt feature. I'd be happy to review any documentation that points to the contrary, though.

I have an LDA (boost enrichment) pump if I need it. I shouldn't, and the N/A pump is capable of flowing enough fuel to reach 15 psi on small turbos, although not without smoke.

All due respect, I need turbo suggestions, not advice on the differences between engines or specific components. On topic, please?

I thought smoke had to do with not having enough O2 to fully combust the fuel? Wouldn't a large boost decrease smoke instead of increase it? On my turbo diesel, it smokes a tiny bit if I lay the hammer down before the turbo spools, and then cleans out as the boost kicks in.

Christ, I don't know much about specific turbo applications, but do you plan to intercool your boost? I believe that would also lower your EGT (exhaust gas temp). More off-topic I know, but I like to learn.

Yep, going to intercool.

The smoke issue I was referring to is when making big boost on a n/a pump. You turn the fuel screw up, and that increases fueling across the board, so you get smoke off boost.

I believe my head gasket has stopped leaking since removing the rotor vanes from the vacuum pump. There was never a compression leak, so its not in bad shape that way.

Where do you want peak torque and hp to hit? Do you want the power delivery to be more truck like ( hit hard from bottom and then stop at like 3600 rpms or so )?

That's precisely what I want, actually. I plan on pulling trailers with this car once it's sorted, and I do like to have done fun occasionally, as well. It already drops power like a brick at 4k rpm, and I'm ok with it. A little more pickup couldn't hurt, and better efficiency isn't a bad thing, either.

I agree with what cleanspeed, Garrett will be a good place to look.

Ok, that's good. Next question; are you going to mount the turbo next to the engine using the factory Ecodiesel manifold, fabbed header, modded NA manifold or do you want to remote mount it?

I got bored and went and calculated the airflow and boost requirement to take the hp level to 95 hp.

The airflow needed is 13.23 pounds per minute.

The boost requirement 14.29 psi

Your pressure ratio is 2.26

These figure came from using the formulas on the Turbo by Garrett site, assuming .38 BSFC, 3600 rpms, 130 degree F intake temp, 2 psi boost loss in the intake system, 1 psi loss due to inlet restriction.

Considering you want to tow, I would want to increase off boost torque by doing a cam swap, as long as it clears the pistons.

Only other thing would be either a water/meth injector or a MSD / Superchips propane injection system set for max economy ( not for power ); it'll really boost the economy.

The rotary style pumps fuel hard down low, and if you got with a good pump shop to adjust the fueling and timing curves so that it has a fast power rise and gets you into the fat part of the boost in the 1500-2500 rpm range, you should be happy with it.

I just found t that thing you were talking about this morning... I was obsessing over the not-compatible-with-android-app they have for awhile.

I could send one of my pumps to giles to get a super pump built, but last I checked, that was like $750... Not wanting to spend that kind of coin yet with so much left to fix. Although his pumps are proven positive.

I'm going to be using the stock N/A manifold, most likely, and mounting the turbo on the side of the engine, above and ahead of the transmission. I'll have an adapter pipe made and a sooty brace that bolts to the bell housing.

That, of course, is if I don't find a good deal on a turbo/manifold that bolts on and fits the criteria.

How much of work and money you are willing to invest?

What you describe from powerband would be easy to obtain with VNT turbo, but many of those require some kind of control, which again requires some electronic work. I guess there was some fully mechanical ones too, but it is bit gray area for me.

One problem with traditional turbo is that if you use small enough to get good boost at low rpm, you will loose top end and easily EGT goes trough the roof at higher rpm, but only way I know how to get boost from idle would be with very small turbo that is too small when going to higher rpm.

Boost build up can be helped with limit pressure valve (google translated term), that does keep wastegate closed until set pressure is reached.

KKK K16 turbo was used small Fiats, it would boost from idle in 1.6l diesel, but it would not be possible to get very good top end, I doubt that it would even work at 4000rpm without causing too high EGT, it is too narrow/tiny but that would do great at lower rpm.

With VNT you would get several size turbos in one, boost would come a lot lower rpm while still being enough big for high rpm.

That is at least how I understand this.

An application like this would not need a VNT style turbo, it would be overkill. The flow requirements are too small and he's not going for the big top end. A fixed geometry turbo with a properly tuned pump will get the job done.

If anything, a little Roots blower would be even better, since boost response is instantaneous; but he didn't ask for that.:p

You don't need to seek big top end with VNT, you can get smaller one that would give that boost from idle, many small diesels around here have such small VNT turbo that boosts from very low rpm and there is not big power at top, torque is flat from 1000rpm to almost 4000rpm.

Regular turbo is really difficult to make work how Christ described, imo. Usually there is not much of boost under 1500rpm in such small motor, unless you put undersize turbo which is then really a problem at higher rpm, in my understanding such setup is very prone to failure, or then turbo exhaust side must be so large that there is no real boost from idle.

Those were the modifications I was referring to.

Gt-15 vnt

US spec TDI 1.9, right?

SRT4 or PTGT Turbos should make it easy enough for your application the SRT4 and PTGT use the same turbo's and can handle up too 20psi

Diesels are designed to run very lean mixtures ( 33 to 1 or better ) and boost is fuel dependent. As long as the fire isn't there, it won't run away boost pressure wise. The more available boost pressure, the better; keeps the egt's down.

That is correct, however the turbine housing is part of the exhaust manifold, so if the bolt patten and ports line up, then your good to go. It's as small as you can get, there is a GT13 available, but it really isn't nessesary with the VNT. This VNT is mechanical and just needs a boost conection to get it working. You can even buy a good quality, inexpensive, Chinese version from CN Racing.

The SRT4 turbo is also part of the manifold and would not fit. It is also a bit bigger than the GT15.

I'd still like to look at the maps of some turbos out there; that will get rid of all the guessing. I'm still wondering about a used Eaton M62 or smaller positive displacement supercharger, shouldn't have let my mind wander.:p:thumbup:

Twin-turbo to solve low end, top end power issue? Ok, I realize this isn't practical.

My next off-topic question is, do turbos boost the efficiency of gasoline engines too? That is, would my 2.4L TSX benefit from a boost?

I do realize the main benefit of a turbo is to allow a smaller size engine to be used while not compromising performance.

Actually, a compound twin set is great for a diesel, and it will allow much cooler EGT's than a single. But for what Christ wants to do, not necessary.

Anything that can introduce more air into an engine will help with the mileage, whether gas or diesel.

Get on Squires Turbo Systems website and see the mpg increases along with the power increase using their setups.

Engines like yours have a lot of port and valve area, so even with all of Honda's engineering tricks, it's light on torque in the low and midrange. By adding boost to get that high flowing head active lower in the rpm range, you don't have to spin the engine up so high to get your car up to speed, and consequently the mpg improves. Honda figured that out and offered their first turbo set up on the Acura RDX.

The secret is being able to run leaner mixtures during off boost situations while cruising along.

I used to have a TD04LR "turbofold" from an srt4... Intended to put it in my Caravan (RIP). They're matched to the manifold, and spool backwards from normal turbos.

A couple points:

I'm not only interested in getting more power here. I chose turbo because it uses essentially wasted heat in the exhaust. I'm not really considering superchargers at this point, as they are parasitic power adders, and even though a turbo add significant exhaust restriction, I don't believe the "cost per return" is as high for a turbo.

Work, I don't mind doing. I don't want to spend a ton on this, though. Frankly, 95hp would be more than sufficient, I think.

I'm looking at around 200 for a turbo, it seems. I might be able to find a decent intercooler cheap or free, and piping it is also basically free. The exhaust will be another story... The stock manifold isn't restrictive at all. The toilet bowl flange connection necks down from 2.5" to 1.5" inside, and that's the exhaust restriction in it's entirety. I want to put the turbo close to the current battery location, which means using the OE manifold, opening the toilet bowl to 2.5 inches, and making a curved pipe to bring the exhaust around to the side of the motor, the a down pipe from the turbo back to the original exhaust location, also 2.5 inch all the way back. All of the necessary exhaust has already been priced out at no more than $150.

A twin turbo setup is definitely overkill, but I may consider it in the future if I end up needing more power. :rolleyes:

I'm going through an idea in my head where instead of turning up my pump and/or using an LDA pump, I'll pipe in propane and tune my non-LDA pump for "normal" operation, where it'll smoke a bit at full pedal or high load. Propane is cheap, and I can adjust it with a quick regulator for the power boost I want at the time. Just an idea, anyway.

Wanted to make sure about this before I said anything about it. Diesel Power Magazine had a shootout last year ( September 2010 issue ) and one of the contestants used a CNG assist system ( Matt Handwork, Duramax ) that won the mileage contest, he did 45.58 mpg. Dmitri Millard did 36 and change by pulsing his nitrous system when taking off, and this is on a 1200+ hp ride.

I think we can do better than that.

It'll probably be better to optimize the fuelling so that you're good to go all the time, because you won't be penalized for it, not at this power level. Plus you know how to drive.

The propane will just be icing on the cake.

You mean tuning the LDA pump to make the power by itself, then just staying out of the pedal when I don't need to use it, right?


Seems like the easiest option, for sure. Really, I'd rather not use propane, because using it effectively mans retarding the injection timing, which I can't really do dynamically. Ok, that's a lie, but it involves a high pressure fuel pump and some electronics.... PITA.

Lol... I have a GT37 VNT from a 6.6 Duramax... Too much?

I had a IHI RHB5 VJ11 turbo, but I think I traded it for something some time... Forgot to look while I was at my fathers house.

Either way, with the LDA or an optimized NA pump. Since you have the discipline to control yourself, you could make the engine more powerful without spewing smoke and melting the thing down. It's the better option.

I guess what I am saying is make the thing run strong, and drive like a good owner/operator trucker.:thumbup:

One more story: Bruce Mallinson over at Pittsburgh Power builds high powered Class 8 diesels and thinks a lot like us. He made his name building up the old, mechanical Cummins NTC and KTA engines to ridiculous power levels while improving the mileage and overall driving ease for the owner ops. These old engines put out 800 to over 1000hp in 80k trucks while being 1-2 mpg better loaded. No need to keep dropping gears in the hills, wearing yourself out because there's 2800-3600 ft/lbs of torque to play with. No electronics, no chemicals, no black smoke. His electronic engines are even stronger.

Hey, I got a crazy idea, since you have the GT37:D.

Take that thing and compound it with a properly sized primary charger.:thumbup: Keep the vane function operable, so she spools nice. Keep everything non wastegated, and control the boost level with the fuel delivery.

No sense letting a good turbo go to waste!

I've heard of people who do that sort of thing, and besides reliability, that's exactly what I'd do, but I want this motor to have OE LIKE reliability. 200hp can be seen with these motors, but it ain't cheap/easy/free by any means.

Right now, peak torque is around 3200. If the turbo started making boost at 2300, it would enhance piling power, and I could stay out of boost under general acceleration.

That turbo cost $50 to ship... It would defeat my front suspension! Lol

I got it from a member on here to use on a gas to diesel project starting with a 300 I6 Ford motor, but haven't had a chance to play with it yet.

Haven't been able to find a VNT Gt15?? Only fixed geo...

Let's go with that. Let's recalculate optimal boost and flowrate to torque peak or 200 rpm ahead of it, which will boost the torque below it, allowing for a lower shift point. Fuel rate and timing curve with a fast rise, pulling to 3600-3800 rpms, goal for 125 ft/lbs of torque per liter ( 200 ft/lbs ) and let the hp fall where it may.

Don't worry about the VNT, if the pump is calibrated properly, the boost will come on strong and there won't be a need for it.:thumbup:

Were still assuming I have the skills to calibrate the pump on my own, and I've never actually done it. I'm usually pretty good stuff like this, but Im gonna start slow, I think.

If it takes a little longer, giles should do the pump if you are not comfortable with it.

Basic rule is 2cc's/1000 strokes/hp

Find out how much the pump puts out, size the injectors accordingly.

The OEM injectors are enough to make 280hp, possibly more. They'll take whatever I throw at them, surely. While I'm working all this out, looking for a great deal, and fixing other aspects of the car, I'm going to rebuild a set of injectors and calibrate them to +/- 1 bar if I can find a gauge sensitive enough.

When those get installed, I'm going to do the IP internal pressure (residual volume) checkand adjustment, then set static timing and increase the fuel until I get smoke, then back it off some.

Right now, I'm driving on less than 50pk hp, so even 80 would be a world of difference, and 80 is doable on the stock n/a pump with basic mods, no turbo.

That will at least get me started, and a properly tuned setup should get me better mileage, as well.

Maybe 70 isn't out of reach...

Recalculated everything so that it's best by 3200 rpms. Using 98 hp as the goal ( 1 hp/ cu in. at 3200 rpms, it'll rev higher than this and still pull to 4000, but now the powerband is real bottom heavy )

13.65 pounds per minute of airflow

18.95 psi boost gauge pressure ( 33.66 absolute )

Pressure ratio is 2.60

So it looks like a GT15 sized turbo will still work with a little more boost.

There weren't any maps available on the website so an exact match couldn't be made, but I'll make a phonecall.