hey guys, for the usmmer i work at a nissan dealer in parts ,delivering, and i was talking to a tech the other day and we were thinking about how i could add more power, other than bolt on, we came up with a twin turbo idea.

He says a basic twin turbo, like a garrett t3 or t4 would work, and that we could find them in a junk yard off some old volvo or volkwagons and put them in, i know puytting in a twin turbo would require a intercooler, blowoff valve allot of new pipes and much more, but how hard do you think this would be to accomplish? has anyone any experience with twin turbo on xterras, i have read a article someone did it on a frontier, not looking for anything crazy, just a few pounds of boost, thanks for the help!

Why would you attempt to fabricate a turbo from junkyard parts instead of going with an already made and proven aftermarket supercharger (which would probably save you quite a bit of cash)? And why would you go with a twin turbo, instead of a larger single turbo? And I don't remember Volvo or Volkswagens ever using the T3 or T4 turbos (could be wrong here, not big into German autos)...

because it is a 6cylinder and a twin would work better, and the power increase gains seem to be better than a supercharger, and with a supercharger wouldn't i have to get a new computer or have mine reprogrammed? but the old volvo stationwagons had turbos on them so volvo could go with a crappy engine and put a turbo on it to make it faster thus saving them money =\ who makes a good aftermarket supercharger for xterras?

Volkswagen and Volvo did not put T3 and definately not T4 turbos in their cars. I have a Jetta TDI (Turbo direct injection). You will still have to probably run a different computer (or at least reprogramed with a different fuel mapping), bigger injectors, possibly different ignition, and probably more stuff. Volvo and Volkswagen didn't take "crappy" engines as you say and throw bigger turbos on them to save money!! They took good, reliable, smaller engines and threw turbos on them to make up for the lack of power with a small engine. That is one of the reasons that Nissan has made underpowered cars for a long time (not in the last 3 years or so), because they made smaller engines that were more reliable and offered better gas mileage. You would still be better off putting on one big turbo if you were to do this (T4/T3 hybrid turbo). People were always taking the 300zx Twin Turbos and just going with one bigger turbo and getting bigger gains.

Last I heard, these guys either have one or are working on one... but anyway... how do you figure a twin would work better just cuz it's a V6? Most Supras that I have seen on the track have traded their two smaller turbos for one larger turbo... I guess both have advantages and disadvantages... this was taken from another forum:
It basically all comes down to size and piping. There are a number of very well cored (ball bearing, low friction) large frame turbo chargers out there today. However, the room under the bonnet of the respective cars is usually the limiting factor - so where it might not be possible to fit a very large single to obtain the horsepower level required, two smaller turbos would be sufficient. The second is piping, the room taken by the pipework and the cost of making said pipework in much cheaper in a large frame single set-up. The cost of two decent wastegates compared to one can make a big difference alone. There are also "tricks" that are possible with a twin set-up that simply can't be achieved on a single, like varied A/R's, etc. On the flip side, with a twin configuration, there is also twice the chance of something going wrong, as virtually everything is doubled up.
But I really don't know a whole lot about this, but from what I have seen, for power the single is usually the way to go...

Someone needs a lesson in engineering and economics. :rolleyes:

And turbos still have no place in gasoline truck engines unless you're a low riding street racer. Too much lag, too much heat, and too much operating cost for the typical use of a truck.

I thought two small turbos are always better than a big one because it responds faster, thus have less lag. Oskana mentioned V6 probably because V6s typically do not pump much air and therefore need smaller turbos to eliminate lag. For example, the minimal amount of exhaust coming out of a 1.6 would take for ever to spool up a single large turbo, but on the other hand, a 8.1 big block would spool that same turbo up in a instant cause it pumps out more exhaust at 1500 rpm than the Civic does at red line.

And yeah, there are many articles saying turbos generally provide more power than superchargers, they also are more efficient because little power is wasted to spool the turbines compared to a pulley driven supercharger.

I do agree that two smaller turbos would have less lag, but piping for two turbos? Where ya gonna put it? But the larger T3/T4 is going to give more overall power... And if lag is a factor, the supercharger is the way to go... And anyway, how much damn power do you need in a top heavy 4x4 SUV?

FYI the VW/Audi turbo's are KKK/K-03, which are similar in A/R and trim to the Garrett T-03.

Small twin turbo's are better than a single large turbo for street applications as they spool up faster, therefore less lag.

As well, engines built for turbocharged use from the factory typically have greatly reduced static compression ratios. That is the biggest reason for a feeling of lag, as the engine will be putting out less power with the low compression ratio (before the boost)

If an engine is kept with a decent static compression ratio (8.5/1) and run with lower boost levels (.5 to .7 bar), intercooled with something like twin K-03/T-03 there will not be any drastic lag.

Think of it this way - a 20V turbo Audi 1.8 engine has put out between 150hp and 225hp through it's life to date. The lag on those engines is gone by 1200 rpm. And they run lower than 8.5/1 static compression ratio. With twin turbos on a 3.3L v-6, you would be giving the eqilivant of 1.65L of displacement to each turbo. Assuming using the same A/R and trim you can expect similar rpm range for boost production. Realise there are other varibles than just displacement...

Truthfully for slow crawling they won't be the best thing. But for sand dunes, mud bogging, towing, and road driving it would be a lot of power.

Both turbo's and superchargers are highly reliable...the quote about twice the things to go wrong - it's physically true, but the idea is flawed. I guess for reliability we should all drive 1-cylinder/1-speed/1-tire cars! :rolleyes:

Ok... point there, but for mud bogging? You might have a clogged intercooler problem... also, if you're looking for a lot more power, aren't there other things to consider? Like your engine internals? Cams, rods, pistons, etc... that's a lot of work and wear that Nissan never planned on while developing the engine... as for VW's, if I remember correctly, they are all based on the diesel platform, making it a very durable engine, able to handle large hp increases such as nitrous, without any internal modifications... just a little different from the X...

Mud bodding was used for a reference of high-RPM power demand - I agree the mud probably would accumulate on the ATAAC/Radiator/Condenser - That's why I don't "Mud".

Everything will wear faster as more power is made from the same displacement. Ideally a twin-turbo Xterra would start with a VG-33ER long block (supercharged engine) to get the upgraded internals...but really I don't think anyone here has examined the parts side-by0side to note specific changes. A stock N/A engine with forged pistons can easily handle .5 to .7 bar. If you compare two identical engines, run on identical duty-cycles the NA and engine will have better longevity than the Forced induction engine. But think about this, most modern gasoline engines can go over 200,000 miles without any internal engine problems - and most vehicles are worn out by then! Who cares if you lose 20% of engine life at that point IMHO.

The VW/Audi 1.8T engines are not derived from diesels. The block architecture is totally wrong to try something like that. They were built specifically to be turbocharged however. But don't forget the 2.7TT Audi engine is a lower displacement (due to lower compression) 2.8N/A engine. As well the volvo T5 is 2.3L -vs- the "light pressure" turbo I-5T at 2.4L...all again the same except for compression ratio.

edited to fix spelling error as noted by the Austin Bartender!

Oh yeah... well you spelled architecture wrong!!! Told ya I didn't know much about it...

Being an ex-Xterra owner and a current Frontier CrewCab owner and a Volvo V70XC AWD 2.4T (Turbo, Intercooler, 5-Cylinder) owner.... (I have previously owned 4 Volvo Turbos..a 84 760, a 97 850 T-5, a 94 850 Turbo)

So... to add my 2 cents worth.... I prefer Turbo-charging over Supercharging. Intercoolers should be used regardless of the application.

1..Why have all the extra power and fuel consumption when it is not needed? (S/C vs Turbo) Turbos will get better gas mileage when compared to Supercharged anytime...not much but at least better.

2..Smaller turbo units turn faster and with less turbo-lag (if any lag at all), as compared to larger units. My 84 760 had a Garrett T2 turbo and took a few seconds to spool up. The 850s and the XC have T3/T4 units and are noticeably less lag and less noise. I sold the 760 after amassing 300k miles on it with the original engine, turbo, intercooler and manual transmission...(and yes it would still go and handle great at 127MPH!)

3..The 760 was a 4 cylinder that developed 170HP with the turbo and intercooler. The 850's both had 5 cylinders and an intercooler and developed 240HP (some models were as high as 270HP). The XC has a newer version of the same 5 cylinder engine with more computer controls, AWD and still an intercooler and develops 200HP.

4..Volvo uses 3 types of turbos for varying applications 4 and 5 cylinder engines get the single turbo unit. All 6 cylinder engines get twin turbos.

5.. I know of a guy in LA who put a Saab turbo (same as the Volvo T2) and a Volvo Intercooler in his 4 cylinder Jeep. It seems to give better get-up and go when he needs it than the Jeep V6.

6.. The other thing is to consider other engine parts and their wear and operation.

7.. Horsepower and Torque... My Volvo develops 200hp @ 400 RPM AND....

over 200 Ft-Lbs of torque from 1800 RPM to 4500RPM!!!

Yes that's flat torque at most any speed. So I have the extra power and reserve whether I am on a dirt road or on the freeway...

Turbos are extreme machines, Volvo (for example) actually changes the bore & stroke of the engines destined for turbocharging (vs the same exact engine for normally aspirated use), among other slight enging changes. Computer controls in todays vehicles have made them more difficult to control, install and run...

Nice idea...I hope it works....and might last as long as a good turbo can....Yes I am opinionated here....

I beg to differ on this one the B200 Series 4-Cylinder engines were not "crappy". Many (with and without) turbos are still running today, after 30+ years in use!!!!!!!!! And was the basis for all of the Volvo 5 cylinder engines in production today.

I would take an old Volvo engine anyday over a new Nissan one!!!!!!!

im glad to hear opinions, and i was right about the volvos using t2 turbos, i would go twin because of faster spool time, and i do need more power for hauling, be it hauling ass, towing or just liking to drive faster than other xterras ...

Turbos are not better for towing. You guys are missing the point. Turbos create a lot of heat and the more load you put on them the hotter they get. If you are towing something of any weight they will get very, very hot and will melt things in the engine compartment. Likewise, offroading creates tons of heat.

I speak from experience!

And considering how hot the air is coming through the vents imagine how hot it's going to be inside the truck with two loaded turbo's...eek!

There's no way the factory exhaust manifolds could handle the heat either, so figure in some headers and lots of shielding and insulation!

I would only do turbos if no offroading or towing were ever involved...otherwise stick with supercharging for the cool operating temperatures and instant power.

So I guess that the turbochargers in most all of the semi-trucks is a mistake then? Yes they are diesels...But have you ever seen a supercharged semi?

Yes heat is an issue, but it can be overcome. The XC has 3 heat-shields between the turbo unit and the firewall. And standing besides the car can sometimes burn my legs from the hot air flowing out from underneath.

I am not going to cut up your rseponse, even though I disagree...

But you do make a good observation about heat rejection...as echoed by Logan.

Factory turbocharged vehicles have been engineered to reject the heat from the turbos, both in the charged air stream and in radiant heat into the engine compartment. Underhood air management is a difficult problem, especially with styling engineers trying to make modern looks without the Peterbilt 379 grille on the front.

Yes you want the turbo's as close to the manifolds/headers as possible, so there is no chance to mount them downstream a little where they would be in the air stream...And just from a basic observation there is not much room inside the engine compartment for the turbos (even though K-03/T-03's are small) unless you remove the pre-cats and relocate them. As well, then you would at least have to cut out the inner fender wells, and fab something new up so water will not splash (crack) the turbo's and manifolds.

It can be done, but realistically unless you have a money tree and REAL knowledge of the subject it would be cost prohibitive.

Oops,, I forgot.... I have an oil cooler too...forgot about that as another "cooling" option.....

And yes I agree as a factory option yes....as an add on....and if you want to keep you vehicle and actually get some use to it before really doing some engine damage....no..... Investigate other sources of power....intake mods, chip changes, exhaust, even just adding an intercooler alone can give you some additional power....

And Carry a fire extingusher!!!!!!!!!!

oskana, this guy might be able to help you out (web page)

Might as well take the body of the X and put it on some other frame and engine than bother trying to strip half of what's already there and then trying to shove the turbos in there....

if you wanted a fast "truck" the X ain't it - especially on the street -

might as well start from scratch with a X body kit.

and then call those Monster Truck geezers on TV - since you've been watching that too much lately, huh?

[QUOTE]Originally posted by *paul:
[QB]oskana, this guy might be able to help you out

I remember that pic... funny how we never saw under the hood....or at least I didn't...... That would be really interesting!!!!!!!!!

How about both? A v8 detroit diesel with a supercharger and turbocharger stacked on top is used on several of the militarys' larger trucks. The turbocharger blows air into the supercharger and the engine puts out 450hp. The sound of that engine under a full load is one of the things I realy miss about the army.

This used to haul tanks but got retired in the mid 1990s. Its nice to see the old work horse is still put to good use.
M911 HET

This is what I learned to offroad in.
M977 HEMTT

maybe it would be easier to simply swap the engine for something with more power.
like a 305. I think this would be less expensive then everything required to successfully add turbos.

just my 0.02 cdn cents.

liv.

the twin turbo actually might not be that hard to do. if you could find someone who swapped out the twin turbo's on there 300zx (vg30 is the same as our vg33) for a single turbo you could probably make that setup work easier than just about any other combo I could think of. this is all academic really because it is impracticle at best to go through all that planning and work on a new xterra. if you really want to go through with it good luck you will need it!

and a as far as superchargers on diesle rigs gmc has been putting superchargers on them for almost 50 years. where do you think the 4-71 6-71 8-71 and 14-71 series of superchargers came from? they are all from gmc diesle rigs. they still put them on too.

The reason they use a turbo with a diesel is to increase acceleration. It has nothing to do with increasing towing capacity. A diesel engine posses enough torque without a turbo. With out it, it takes diesels forever to accelerate. 1998 Volkswagen Jetta Turbo Diesel!

That one I know I had a 1981 VW Rabbit Diesel...WITHOUT a turbo....SSLLOOWW! But 56 MPG!

Sorry to bust all of the diesel bubbles...

1) Turbo's are not only on Diesels to hel with acceleration. They are they to provide power throughout the RPM range. Take a Detroit Diesel 6V-92 TA (Turbocharged/Aftercooled) it can be rated up to 400HP. The same engine N/A (with a blower) will rate up to 250HP. Both power ratings are at 2100 rpm/max. Yes the turbo engine will accelerate faster, but it will also have more power under a load.

2) The Detroit Diesels have a blower not a supercharger. A blower moves mass quantities of air without a pressure increase, a supercharger compresses the air much like a turbo. These engines that use a blower are two-stroke, and need the blower to operate. And when are only equipped with a blower are termed "Naturally aspirated". The maximum pressure attained by a blower in one of these engines is about 1.5psi.

It's too hard to manage a twin turbo set up. What engine management computer are you going to use? What are you going to do about the compression? What about the other components like the fuel pump, injectors, ignition system, exhaust. There are too many components that need to be replaced or upgraded to control such a set up.

How do you plan on offroading in a truck with turbo lag in the lower rpm? Crawling requires low end torque and smoothness. Imagine trying to crawl up a wall when the boost kicks in. The reason most trucks use superchargers is because it's power curve is usually linear. Not a good idea, too much money and you'll always have problems. Why not just replace it with the VQ and have 240 ponies? It would be a lot easier, less expensive, and more reliable than TTing your X.

The heat thing is no joke, my Supra's hood is beginning to discolor from the T04 that I put in it.

well i do appreciate all of your imputs, the only reason i am considering this is because i work around all types of mechanics IN nissan parts and i can get basically any part at a good price, and i iwll be honest, i just like to drive fast, and i know that the xterra is top heavy and i don't like taking it over 100.

I would go supercharger except for the fact that there are no aftermarket ones and putting a stock supercharger on a un-supercharged xterra would be a bitch, we considered that, and i would add new pistons, cams, intercooler and heat shields to keep it under reasonable usage, and wasn't there a frontier on here that someone talked about that had turbos put on it somewhere in florida? thanks guys, keep ideas rolling =D

Aftermarket Superchargers

If you are waiting for a bolt on kit it's not going to happen.

heh, i wasn't waiting for a bolt on, but i tried searching it must have came out pretty recently, thanks though

eh dont really find that too useful, i mean they have them for a 350z..

I think I'll just swap out to the engine the 350z uses, can't be all that hard, can it?

Oskana, if you are really interested why don't you read up on the subject?

http://www.amazon.com/exec/obidos/ASIN/0837601606/qid%3D1060910854/sr%3D11-1/ref%3Dsr%5F11%5F1/104-2228599-0998300

Many of the books under the "What other bought" section are also very good, but Corkey is widely considered the godfather of turbo's. He's also a hell of a nice guy

But there is an aftermarket bolt-on kit:

http://www.tonemonday.com

thanks for the imput, helps allot

Brad , it's interesting that that place you listed is in Texas yet on the site it says "You Will Be Notified Of Freight Charges From Zip 92821." That is in Brea , Ca. I wonder if it's a Brea company that's doing the work and the kit and these guys are drop shipping them.

Yes. Tonemonday is a reseller. I believe Alpine Developments is actually a South African company with a distributor in California.

Keep the supercharger, add the turbos. More power, no lag.

Huh? Who in their right mind would add turbos on top of a supercharger?

Actually a few people.....

Supercharged and Turbocharged Engine

HKS put out a kit for the 86-89 MR2's also. I suppose if you have money to burn it's not that bad of an idea.

Seems pretty stupid to me for an Xterra though. :rolleyes:

Well first think about what I wrote. Then you will discover that the application is a respectable solution to the problem at hand. To overcome the lag properties of turbos add a supercharger. You can even shut off the charger valve when the turbo kicks in. Or f*ck keep it flowing.

LOOK AT THIS ARTICLE:

http://www.europeancarweb.com/features/0308ec_bmwbattle/

THEN LOOK AT THIS ARTICLE:

http://www.europeancarweb.com/features/0308ec_grandprixvolvo/

And this is what a VOLVO beat out:

Eight Great Contenders for Car of the Year

(Volvo S60R)
Mercedes-Benz E500
Porsche Boxster S
BMW Z4 Roadster
Saab 9-3
Jaguar XJR
New Beetle Convertible
Audi RS6

Cool. Too bad it's still a Volvo.

HKS made a turbo charger option on the supercharged MR2 AW11 called the twin charger system. Produced in excess of 300hp in a car that weighed in at 2200lbs. Now that is power.

Is it just me, or is it completely odd that a Bettle is in that list?