Thread: Quick question about wiring

Originally Posted by c.h.i.e.f

thanks heaps john so in your opinion the GT2871R would be the best turbo to run out of all the possible single turbo units? with your twin turbo setup what size turbos are you running? from what i can gather and you have already stated the torque cam needs to be modified so that there isnt as much fueling down low which i can notice it seems like it is starving in the higher revs...how far off getting your setup running?

For the conditions/requirements that I put into the turbo calculator - click on the link in the post above and read what they were - the GT2871R and GT3071R both looked suitable (note there are several compressor options for the GT2871R and the one I mentioned has 48 trim - this is important. Use the link to compare it to the other compressor maps).

The smaller turbine of the GT2871R will spool up quicker than the GT3071R. Note that the 71mm compressor wheel needs more torque to drive it than a 60mm wheel that others on here are using.

The big advantage of the larger compressor wheel is greater efficiency - the compressor can flow more air and deliver denser air at lower boost pressure because it doesn't put as much heat into the air. Boost pressure is a function of tip speed squared. Flow is limited by inducer (inlet) diameter squared (area). Trim affects efficiency.

If you want to produce more power than I chose in those calculations then the GT3071R has much more scope for improvement, but this will need more fuel from your IP than easily obtained by external screw adjustment. The torque cam is adjusted through a hole (with welch plug) in the rear of the governor housing using a special tool - it will wake the engine up if you have the air to burn it.

My compound set is the same as used on 4.5 litre, V6, Maxxforce 5, diesel from Navistar.

It is an R2S (regulated 2 stage) Borgwarner. The high pressure stage is the same size as their K16 turbo and the low pressure is the same as their K27.2

I have too much on my plate at the moment to get it running.

thanks heaps john very helpful
well seeing as though theoretically the gt3071 is capable of producing more power with increased fuel seeing as though it is still larger than the others even if there was increased fueling you would only get to a certain point before having to increase max governor speed to notice a big difference wouldnt you? unless the torque cam can be modified so that it can deliver an even amount of fuel from 750rpm-standard 3200rpm...

john you used to live close to myself, where did you find best to get diesel injection work done?

ill have a play around with that turbo calculator asap but from what your saying the gt2871r is about the pic for a single turbo setup so ill take that as a starting point

Originally Posted by c.h.i.e.f

thanks heaps john very helpful
well seeing as though theoretically the gt3071 is capable of producing more power with increased fuel seeing as though it is still larger than the others even if there was increased fueling you would only get to a certain point before having to increase max governor speed to notice a big difference wouldnt you? unless the torque cam can be modified so that it can deliver an even amount of fuel from 750rpm-standard 3200rpm...

john you used to live close to myself, where did you find best to get diesel injection work done?

ill have a play around with that turbo calculator asap but from what your saying the gt2871r is about the pic for a single turbo setup so ill take that as a starting point

With Garrett naming convention, the 1st 2 numbers relate to the frame or turbine size (but what size I don't know, except smaller number = smaller turbine). The last 2 numbers are the diameter of the compressor wheel (exducer) in mm.

So all of the xx71 have the same diameter compressor exducer, but some can have different sizes of inducer, so then they will have a different trim, as relates the inducer to exducer areas. Inducer size limits max flow from the compressor.

If you look at the GT3071 map you can see that the red dots corresponding to the points of interest that I input have room to go right (increased mass flow) and up (increased pressure ratio/boost) while still being within a region of good efficiency. In this respect it is the best choice for max power (top end), but the GT2871, with its smaller turbine will spool faster and may be more drivable under other circumstances.

When I used the calculator that I linked to, I was rushing and didn't pay any attention to the inlet manifold temperatures - further passes with more appropriate temps are required to be realistic. The link I provided will input the values that I used, but you are free to modify the inputs as you wish, once you open it.

These turbos with 71mm compressors are no comparison to the tiny turbo you have now, which is too small for a tuned 300Tdi or TD5 IMHO and way off the map for a 4BD1 with fuel turned up.

IMO a 60mm compressor wheel will deliver enough air for a 4BD1 with the fuel turned up, but not have the potential of a 71mm compressor wheel with the IP is adjusted for near max fuel.

Torque and power will be increased without increasing the max speed setting of the governor. Torque is gained by burning more fuel at any particular engine speed.

Even though the effective plunger stroke may be the same, Bosch claim that delivery increases as IP speed increases and the governor has to adjust for this - I presume less leakage at higher speed. The RLD governor on our IP's adjusts for speed and load - the profile of the torque cam is a vital part of this.

Can a mod amend the topic of this thread so the good info on turbos doesn't get lost?

flagg thats a great idea new thread by mod would be handy!
thanks john once again...
yeah the turbo i am running at the moment is pratically useless even though it is well out performing any diesel in my local area it has alot of room for improvement! i found the cause of lacking in fuel delivery and it was a stupid but surprising mistake and the problem was the throtle cable i placed the accelerator pedal to the floor and then adjusted it at the IP pump because it had that much slack i dont want to mention it its to embarrasing it now revs free and feels much better...
at the same time i modified the intercooler hoses and clamps and got rid of my modified exhaust manifold and went with a genuine one with a adaptor plate that fits the triangle flange type turbos such as the gt2052s im running i designed it to incorporate a egt probe hole also.
it has great power but only for a very short duration then it dies off as expected from such a turbo choice... i have a tb28 (i think from what dougal said) it of an 4.5 or 4.7L isuzu truck not sure on the exact details at the moment as i am not at home again but i am thinking of giving it a trial run to see how it goes... whilst running with the smaller one on at the moment im not sure what my 0-100km time is but its quick and have to be carefull with the temps as 750*c takes a matter of probably 4seconds if foot planted so i back straight off...
about the torque cam i was talking to bosch australia and they instantly said that they have had a few people with these motors wanting the torque cam ground and have "suposedly" blown there motors up due to high temps even though i was trying to explain to this person that yes i can see how people melt them but with the appropriate instruments and guages it can be made safe! he then started to say how little everyone knows about how a diesel works (specifically aiming it at us isuzu owners) and then said the torque cam is directly proportional to the fuel screw and once you touch the fuel screw it will alter the fuel delivery and muck everything up so i may as well talked to the wall...
nowhere seems willing to modify diesel pumps to deliver more fuel they are all to worried about customers "blowing" there motors up but they dont understand that if temps are monitored you can have as much fuel on tap it depends on how much air you can get in and temps inside the chambers from what i can gather! hence carcrafter22 having over 300cc/1000strokes of fuel but he hasnt blown his up....

i shal look into the turbo maps for various turbos i am still contemplating on what i shal do turbo/pump wise?

oh and thanks again guys for the help with this stuff because trying to find out info on diesel performance from diesel services etc etc is like talking to the secret service

i have been looking at the wiring in the 110 and i have 2 questions just to clarify to make sure i am not barking up the wrong tree

1.mine is a standard 110 isuzu county 1986 everything is original (apart from what i have changed or modified) does it actually have an "external" voltage regulator?

2.if yes, can someone please show me a photo as to what i am looking at so i can be 100% sure.

Originally Posted by c.h.i.e.f

i have been looking at the wiring in the 110 and i have 2 questions just to clarify to make sure i am not barking up the wrong tree

1.mine is a standard 110 isuzu county 1986 everything is original (apart from what i have changed or modified) does it actually have an "external" voltage regulator?

2.if yes, can someone please show me a photo as to what i am looking at so i can be 100% sure.

It's internal to the standard nippon alt.