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Ok, the story goes:
1 tired 3b gets rebuild and AXT turbo kit
after run in angine is serviced/checked by mechanic
1 unsatisfied owner eventually believes he has an ok engine and that he was just expecting too much
Dyno shows 36 kW at the wheels
According to AXT this is about right for the middy to be running this low output. Does anyone have any suggestions as to where to go from here power increase-wise? Please consider that this engine has cost me too much to throw away.
I would also be interested in hearing what other 3b owners have had there rigs pulling on a dyno.
Trusa wrote:Ok, the story goes: 1 tired 3b gets rebuild and AXT turbo kit after run in angine is serviced/checked by mechanic 1 unsatisfied owner eventually believes he has an ok engine and that he was just expecting too much Dyno shows 36 kW at the wheels
According to AXT this is about right for the middy to be running this low output. Does anyone have any suggestions as to where to go from here power increase-wise? Please consider that this engine has cost me too much to throw away.
I would also be interested in hearing what other 3b owners have had there rigs pulling on a dyno.
I had my turbo fitted by AXT back in 2003. The engine had just clicked over 200,000 and this was the dyno report. I did take it back after around a month later and turned up the boost but I don't have a dyno report for that.
Dazz
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Last edited by bj42turbo on Wed Mar 30, 2005 6:26 pm, edited 1 time in total.
Seeing how AXT weren't too interested in helping I am going to Denco in Wagga (closer anyway) for a dyno tune and their opinion on performance. From there I guess I will decide what to do. After $14000 on this engine and only dissapointment I'm reluctant to start on a new engine tho. That's a years wage for me!
you could have chucked all manner of late model motors or v8 diesels in for that money.
i feel for you though. i was the proud owner of a SD25 diesel in a navara once. It was originally designed as a plant motor to run at a set rpm, in a truck all it did was add weight to the front end!!!
Im new to the 4x4 scence but having a long history with turboed/dynoed petrol cars you learn a few things.
First dyno figures are BULL SHIT and only good for pub talk.
The figures listed on AXT site are flywheel figures not at the wheel (ATW) which is what your getting when you say 31kw. When measuring ATW compared to at the fly wheel (ATFW) you typicaly get a loss of around 30-50% depending on if car is 2wd/4wd etc. but also what gear they run the dyno run in is very important, they should use the gear closest to 1:1 which on a BJ 4 speed is easy its 4th :-)
Also youd expect more loss in 4H than 2H etc. But I must admit Id have thought you would have got 50kw+ with that setup assuming dyno is done in 4th and 2H. Also realise different tyre sizes and even pressures make a difference to dyno readings.
The proof should be how it drives, and by sounds of it your not happy with that either.....
fawk 13 big ones ouch i paid $5500 for a reco 3b what the rest pay for gold plating i hope one bennifit to you tho i just put mine on its side n fawked it if i do a buy back off the insurance tho the 14bt is gunna get fitted
man yeah for that $$$ i would be camping on their front lawn til i got satisfaction!!!!!
but didnt you think when they said 14 grand NAH i go get a CHEV V8 Diesel and TURBO it hardcore???
man my whole 40 owes me half that. its a shitter petrol but still....
things like the turbo size and boost pressure.
exhaust size and what muffler/s?
size of the exhaust that sits directly after the turbo.
intake pipe size.
intercooled?
air filter setup
basicly every thing.
that way we can try and track down where the biggest restriction to power is and how to go about fixing it
"First dyno figures are BULL SHIT and only good for pub talk."
Please explain. If done by a reputable operater, how can they be "BULL SHIT".
Yes, flywheel figures and at the wheel or rear wheel figures do alter drastically. There is no hard and fast rule as to how much power the driveline looses.
For 13k, everything should have been overhauled. What are air/fuel ratios and boost pressure settings?
Dzltec wrote:"First dyno figures are BULL SHIT and only good for pub talk."
Please explain. If done by a reputable operater, how can they be "BULL SHIT".
Yes, flywheel figures and at the wheel or rear wheel figures do alter drastically. There is no hard and fast rule as to how much power the driveline looses.
For 13k, everything should have been overhauled. What are air/fuel ratios and boost pressure settings?
Cheers
dyno numbers are too easy to fudge.
we have three dynos in town and none of the ever get the same reading.
and all operators claim to be reputable. but the sad truth is not many of them are. i know of one, that the more money you send with him the higher the read out. even if your car has not changed
dyno runs will alter from day to day based on atmospheric conditions
the operator generally compensates for this, which introduces error into the system.
The only real use of a dyno is for before and after runs so you can see how much gain has been produced by a mod etc, again these wont be 100% accurate, but if done on the same machine by the same operator they will be close.
v840 wrote:
[Not a shot at Tonka] It's like saying, hell I've got two nuts, I may as well cut one of them off for the hell of it. I ain't using it.[/NAS@T] It's ridiculous!
dumbdunce wrote:The later 3B-II (5 camshaft bearings, rotatry fuel pump etc) as in your BJ73, should be good for approx 100 flywheel kW with turbo, without intercooling, if correctly tuned. that should equate to about 70 rear wheel kW in 4th gear on a dyno, regardless of the tyre size. (although big tyres might slip on dyno rollers and givce an incorrect rpm reading)
as for what you have paid for, I don't know what's included in your $14000 but that sounds like a lot too much to me - a turbo setup, fully installed including a full exhaust should not cost more than about $3500, and can be done for a lot less. the engine rebuild including all new pistons, seals, gaskets, rebore, even a new camshaft and timing gears could not possibly cost more than about $5000 - a replacement jap import low km 13B-T motor can certainly be bought for around $5000 give or take a bit.
indicators of the quality of the rebuild will be noises from the engine - the later 3B motors are fairly quiet in operation - if it rattles or clumks. smoke - if it makes blue (oil) smoke, there's something not right - the rings have not seated in the bores. If it makes white smoke, the compression is poor and it is not burning the fuel. If it makes black smoke, it is overfuelling and the pump or injecotrs need attention. If it consumes any oil at all, something is not right, these motors are famous for not using a drop between changes. Test for blowby by disconnecting the crankcase breather from the inlet and feeling the breeze out of the pipe with your hand - at idle it should be barely noticable, and as you reve up, it shoild not get much more prevalent on a new motor.
was the motor built and tuned by a diesel specialist? these motors are very fussy about tuning and need the fuelling to be set up just right.
another possibility is that the timing gear on teh fuel pump is one tooth retarded or advance - it will run, but it will be rough and low on power. will probably also cause smoke of the grey or black varieties.
I don't know any specialists near you who can help in a more practical way. Denco in Wagga Wagga are very good (about 150km from Albury?) and it might be worth the trip - give them a call and ask anyway. Jon Bruest is the man to talk to.
Unless your rebuild included some pretty special stuff, and included overhauling your gearbox, transfer, diffs etc, my feeling is you have been ripped off (of course I don't know all the details) even if your motor rebuild is working fine.
If I was going to diagnose this engine, I'd first take it for a drive and see how it feels and sounds, and observe any smoke issues. then I would statically check and set the injection timing, then take it for a drive with a boost gauge and exhaust pyrometer attached. I'd be looking for exhaust temperatures peaking around 600 degrees C (post turbo), and peak boost levels around 8psi, with zero smoke - if these don't fall within expected ranges, tuning the fuelling and wastegate until they are where we want them. It should feel reasonably lively to drive (but not really all that exciting!) - should accelerate smoothly and easily, and be able to cruise at 120km/h (about 105 indicated if you have not recalibrated your speedo for the 35's) without any trouble at all.
Ozlegacy - The proof should be how it drives, and after a rebuild and turbo I would expect to be able to climb some things i keep stalling out on and at least not get passed by fully laden semi's on the highway. I appreciate that dyno figures may not relate totally to driving performance but unfortunately it's the best way to find out what the car is actually putting out compared with what it should be.
Brad-chevlux - I am unsure about many of those details however I can tell you this:
7 psi boost
2.5" exhaust from back of turbo turning into 3" (don't bother telling me how useless that is) with 1 supposedly high flow muffler
don't know intake pipe size, air filter setup is standard with snorkel, no intercooler
The go from here is I am taking the truck to Wagga and getting Denco to check over my set up, tune it and make any other changes suggestions they think may be neccesary. At this time i will find out more about my turbo size, intake pipe size and tuning details. I hope it works!!
shorty_f0rty wrote: leaning towards denco anyway.. this is more food for thought.
I was under the impression AXT were the only ones who did a turbo kit for a 3B
Dazz
i think i started a 3b turbo thread ages ago (search should find it ) which details a lot of options, one of which was denco with a schwitzer turbo, and kicks in lower in the power band too..
if only my funds could keep up with my mod list :( this would definately be at the top of the list to do
Trusa what size intake and exhaust do you have, even for my natural breather a snorkel, extractors, 2.25 pipe and a consistently clean air filter help a lot, let alone for a turbomacated motor..
cheers scotto
for the record...
My research led me to a Denco turbo (schwitzer type, kicks in just above idle and phases out by 2.5-3k rpm, 3" straight through, intercooled and running on 9psi to be safe on a 260 thousand k 3b. Apparently will not subject engine to stress beyond what it already runs at.
This set up would cost around $4500 which to me is a lot of new wine in an old bottle
I have different plans now
) which details a lot of options, one of which was denco with a schwitzer turbo, and kicks in lower in the power band too..
