Any built 300tdi D1 owners here?

[David Harris]

Thats a great calculator. So, with 4.56 gears, stock transfer case gearing, and 33's, 65mph nets me ~2680 rpm. Where is a stock 300tdi powered Disco at rpm wise at 65mph? Is 2680 rpm too high?

With 235 70R16 tires, which is the stock size, the diesel and V8 Discos are turning 2372 RPM at 65. So, 4:56 on 33's would be a bit higher RPM. This would be OK for the V8, I think, but the 300 Tdi develops maximum torque at 1800-1900 RPM, so it may be too low gearing for the diesel. However, I think it also depends on how much weight your carrying and what kind of grades you're expecting. The lower gearing would allow you to come down in speed some on grades and would definitely be better for low speed acceleration. That turbo would spool right up with those gears at a low speed. If you're searching for maximum economy, lower RPM's are better with the diesel, so I would go 4.10's. East Coast Rover did 4.10's and the stock 1.2 transfer case on their Discotech with 33's and they liked it. However, they had an R380 manual. The auto needs more gearing to start out smartly from a stop.

 

[Viggen]

I read that on their site a little bit ago about their ratios. The R380s 5th gear is almost the same as the ZF 4th gear so if it works for them, itll probably work for me. Im not going to be as loaded down as some of the rigs. Im not running an RTT and with the diesel, I wont have to carry a few gerry cans of extra fuel. I do have a fridge, full SD rack, ARB w/ winch, and a few lamps.

Does anyone know where the stock motor cruises at 65? Since the ratios are the same as the V8 trans, the calculator shows me ~2381 at 65 in 4th. Sound about right?

 

[David Harris]

Does anyone know where the stock motor cruises at 65? Since the ratios are the same as the V8 trans, the calculator shows me ~2381 at 65 in 4th. Sound about right?

Yes. Spot on. 4.10's are a great choice . . . Autos also have another great advantage over manuals, and that's torque multiplication at low speeds, that is they're not locked-up all the time like manuals. Their inherent slippage at anything other than fourth gear lock-up means that they are in fact acting as a variable gear ratio. You can get by with taller gearing in an auto as a result. Thus, when you start out, the auto is acting as if it is much lower geared than it actually is. This slippage is why you can just keep it in gear against the brakes when you stop, and it won't stall. However, this slippage comes at a cost, which is high heat build-up and less efficient power transmission when it isn't locked-up. Therefore, you have to keep autos cool. Not a problem with the Disco, though, since it has two trans coolers stock, one external and one in the radiator. The R380 isn't the coolest running manual trans anyway.

 

[piper109]

Well this thread went wild didn't it !!

The stock 300tdi Disco has a 1.22 transfer case, 3.54 axle ratios and is essentially geared the same as the V8. My conversion certainly is the same as I am still using my original drive train and transfer case bolted to the back of an R380 and 300tdi engine that I personally imported from Wales.
And yes I am an expat Brit who dislikes v8 engines and their insatiable thirst.
I like getting ~450 miles to a tank instead of ~250

Britain has wonderful hills and mountains as does the USA.
Take an American to the Lake District on a rare sunny day and they will be in awe. My wife was and she grew up at 3200 ft. I am in awe anywhere west of Denver.
The big difference is altitude. I worked (engineer) for an American manufacturer of Railroad machines. They imported a British machine from a subsidiary who said it had plenty of power. It was naturally aspirated, not turbo.
When it fell on its behind at 5000ft and above I told them they had forgotten a small detail. When I told the British engineer we were working in Wyoming at 6300ft he said "gould blimey I never thought of that!!". The highest point on the UK rail system is a bit over 2000ft.

Steve......very happy with his mildly tweaked 300tdi D1 in the Carolinas

 

[David Harris]

Britain has wonderful hills and mountains as does the USA. Take an American to the Lake District on a rare sunny day and they will be in awe. My wife was and she grew up at 3200 ft. I am in awe anywhere west of Denver.

Indeed, Steve. When I lived there, the Lake District made some of my fondest memories of all. I hiked all over there and still remember thinking to myself that it was a heaven on Earth if there ever was one. I grew-up in Colorado, and I still count it as my home. The western United States is also a unique heaven, especially for outdoors people. There is a certain sense of wildness there that no other place I've been has.

 

[Nonimouse]

Just a little point

THe 200/300Tdi's are only little engines and reliant on forced induction. In simple terms to gain power you will lose it elsewhere; i.e. an increase in Mid Range to Top End equates to a loss at the lower end of the scale. In a stock vehicle peak torque is low at 1800-1900rpm ish. But when this changes to about 2200 as you tweak. You can bring the standard turbo in earlier but then you lose out at the top. I don't have a rolling road in my shed but I'm sure you get the gist without loads of figures. Things change again for the later 300Tdi's with the electric gubbins on the fuel pump.

I've had a dyno'd 150+ bhp out of a 200Tdi before with a standard turbo (and 265ft/lb) but it was a dog to drive anywhere but flat tarmac as all the bottom end had left and gone on holiday.

I now tune for driveability, avoiding figures and dynos. It's so easy to tweak a Tdi it seems to work better this way. I stick to the basic rules - breathe better, flow better; so big bore snorkel, OE filter, smooth pipes, no center box, change/re-con the injectors every 60k, plus50% cooler and then just tweak by small increments with lots of testing. Okay my 110 is geared to almost stock and has no major external bolt ons (I've even just taken the ARB bumper off for a while and gone back to standard with a bikini mount) and I watch the weight (low sugar, low salt, no fat, plenty of exercise) but I average 33-35 mpg (imperial gallons) and my speed is governed by rpm and the legal speed limits. I could happily pull an overdrive.


Back to mountains; this is Sgurr Dearg on the Isle of Skye: http://www.thewalkingwestie.com/images/alasdair/large/inpin.jpg

Sky is mountains, but not one is higher than 1000m. Yet the greatest climbers in the world admit that Skye must be taken very seriously. Weather and terrain make it lethal; but it's shear beauty is enough to make you weep. Mountains are God's way of letting you appreciate the view

 

[R_Lefebvre]

Well this thread went wild didn't it !!

Yes, his has turned into the most productive thread in this forum in a long time.

I saw it a few days ago but didn't comment, I think it was in this thread. Somebody mentioned something about the difference between the R380 for the V8, and the 300Tdi. The difference between the boxes is the bellhousing (obviously) and also the input shaft. The R380 could be moved from a V8 to a 300 by changing the input shaft during a teardown. The gear ratios are also minorly different.

 

[piper109]

Just a little point

smooth pipes

Back to mountains; this is Sgurr Dearg on the Isle of Skye: http://www.thewalkingwestie.com/images/alasdair/large/inpin.jpg

Sky is mountains, but not one is higher than 1000m. Yet the greatest climbers in the world admit that Skye must be taken very seriously. Weather and terrain make it lethal; but it's shear beauty is enough to make you weep. Mountains are God's way of letting you appreciate the view

Yes the Isle of Skye is a magic place. Its the home of much haunting music as well.

I too like to have smooth, well tuned pipes but most of mine are not on the Disco

 

[Red90]

I've had a dyno'd 150+ bhp out of a 200Tdi before with a standard turbo (and 265ft/lb) but it was a dog to drive anywhere but flat tarmac as all the bottom end had left and gone on holiday.

You obviously have not driven one with a VNT. Peak torque at 1400 rpm. Pulls like a train from idle. You CAN have the best of both worlds.

 

[R_Lefebvre]

Not even exclusively VNT. The latest Garrett GT turbos kick the stuffing out of all the old T series on drivability throughout the rev range. My GT28R is capable of pushing enough air for ~300hp, but I'm making full boost by 2800rpm on a 2.0L. The Ball Bearings help, but the big gains are in the turbine efficiency.

Previous to that, I had a VNT turbo on it, maxed out at 220hp worth of airflow, and only hit full boost at 2400rpm on the same motor. I'm not sold on the durability of VNT's, as mine blew up, which is why I got the GT.

 

[piper109]

Not even exclusively VNT. The latest Garrett GT turbos kick the stuffing out of all the old T series on drivability throughout the rev range. My GT28R is capable of pushing enough air for ~300hp, but I'm making full boost by 2800rpm on a 2.0L. The Ball Bearings help, but the big gains are in the turbine efficiency.

Previous to that, I had a VNT turbo on it, maxed out at 220hp worth of airflow, and only hit full boost at 2400rpm on the same motor. I'm not sold on the durability of VNT's, as mine blew up, which is why I got the GT.

I am completely green on turbos. Could you please expand a bit or point to websites I can swat up.
What is a VNT and how does it differ from my stock turbo rebuild with a bigger impeller?
Is it a straight swap?

I am mostly interested in improving low down performance as it seems that is where I am lacking the most. It seems to sag on hills much below 2000 rpm. My only tweak has been to rotate the diphragm about 110 degrees but I also have no EGR, no cat, very free flowing 3" exhaust, stock air cleaner.

 

[R_Lefebvre]

VNT is a different way of controlling boost. Way back, the turbine was sized to not overboost when the engine was at full power. They were very laggy. Then the invented wastegates. The turbine could be shrunk to make full boost lower down in the power band, and then allow exhaust gas to bypass the turbine at high rpm so that the turbo doesn't overboost. VNT does away with the wastegate, and uses vanes which move to change the exhaust gas' angle of attack on the turbine wheel to control boost.

[ame="http://www.youtube.com/watch?v=Gc2awh0O0Bc"]YouTube- ‪Garrett VNT turbocharger cutaway animation‬‎[/ame]

Spoolup times are even better.

However, I have had the vanes jam. They coke up. And the actuator mechanism can seize if the car sits for a while. Eventually, my vanes sheared right off and went through the turbine.

The GT turbos are not generally VNT, but the impeller and compressor aerodynamics are greatly improved over the old T series. You'd likely see an improvement with a properly matched GT. I'm not a big fan of hydrids, turbine clipping, or any of that stuff commonly done in the aftermarket to hotrod a turbo.

 

[jrose609]

You obviously have not driven one with a VNT. Peak torque at 1400 rpm. Pulls like a train from idle. You CAN have the best of both worlds.

Where did you pick up your VNT turbo?

 

[AxeAngel]

VNT is a different way of controlling boost. Way back, the turbine was sized to not overboost when the engine was at full power. They were very laggy. Then the invented wastegates. The turbine could be shrunk to make full boost lower down in the power band, and then allow exhaust gas to bypass the turbine at high rpm so that the turbo doesn't overboost. VNT does away with the wastegate, and uses vanes which move to change the exhaust gas' angle of attack on the turbine wheel to control boost.

YouTube- ‪Garrett VNT turbocharger cutaway animation‬‎

Spoolup times are even better.

However, I have had the vanes jam. They coke up. And the actuator mechanism can seize if the car sits for a while. Eventually, my vanes sheared right off and went through the turbine.

The GT turbos are not generally VNT, but the impeller and compressor aerodynamics are greatly improved over the old T series. You'd likely see an improvement with a properly matched GT. I'm not a big fan of hydrids, turbine clipping, or any of that stuff commonly done in the aftermarket to hotrod a turbo.

Rob, sounds like you and I need to edjumucate some folks about impeller and exhaust sizes. To be fair I think the t3super60 is better for these applications while the gt28 is better on our smaller engine but higher revving track cars. T3s60 is super cheap too. Not bad spool either given the displacement.

-Sam

 

[Red90]

Not even exclusively VNT. The latest Garrett GT turbos kick the stuffing out of all the old T series on drivability throughout the rev range. My GT28R is capable of pushing enough air for ~300hp, but I'm making full boost by 2800rpm on a 2.0L. The Ball Bearings help, but the big gains are in the turbine efficiency.

Previous to that, I had a VNT turbo on it, maxed out at 220hp worth of airflow, and only hit full boost at 2400rpm on the same motor. I'm not sold on the durability of VNT's, as mine blew up, which is why I got the GT.

Apples and oranges. You are comparing a VNT on a petrol....

On a diesel, they are magic. They are simple to control and peak torque goes way down in the rev range, basically killing turbo lag. Every diesel engine in the last ten years, at least, has one. Because the normal power band on a diesel is so small this makes a huge difference in driveability.