MTQ TURBOCHARGER ENHANCEMENT KIT to 300tdi

[29dinosaur]

To borrow from the td5 to 300tdi thread......

Has anyone done the MTQ TURBOCHARGER ENHANCEMENT KIT (http://www.mtqes.com.au/products.php?action=vehicle&id=6) to a 300tdi and can offer feedback?

[Taz]

I think my brother in law has one in his auto D1. All I know is that it's a non standard turbo that is water cooled. I dont know of any other common conversions, so my guess is that it's a DTS job. We purchased the car with it already fitted and the dealer didnt know the history.

The performance of this car is poor. It's considerably worse than my manual D1. He recently fitted a turbo guage and found that it was setup for 12psi max boost. So there is potential for improvement. And maybe the poor performance is totally attributed to poor setup.

However I struggle to understand how MTQ managed 101kw if they retained the max boost pressure. Sure it may produce more torque by spinning up sooner, however it would have to produce a heap of torque to influence the max power point in the rev range. Since the standard turbo produces max boost at around 2300rpm, I dont understand how any performance increase can be achieved above this, if you retain the same max boost. But I'm no turbo expert. Perhaps a more efficient turbo design will reduce the exhaust back pressure and hence inprove performance - I dunno.

[Dougal]

I think my brother in law has one in his auto D1. All I know is that it's a non standard turbo that is water cooled. I dont know of any other common conversions, so my guess is that it's a DTS job. We purchased the car with it already fitted and the dealer didnt know the history.

The performance of this car is poor. It's considerably worse than my manual D1. He recently fitted a turbo guage and found that it was setup for 12psi max boost. So there is potential for improvement. And maybe the poor performance is totally attributed to poor setup.

However I struggle to understand how MTQ managed 101kw if they retained the max boost pressure. Sure it may produce more torque by spinning up sooner, however it would have to produce a heap of torque to influence the max power point in the rev range. Since the standard turbo produces max boost at around 2300rpm, I dont understand how any performance increase can be achieved above this, if you retain the same max boost. But I'm no turbo expert. Perhaps a more efficient turbo design will reduce the exhaust back pressure and hence inprove performance - I dunno.

Getting more power depends on where your turbo currently is. Just screwing with the wastegate to gain boost and upping the fuel will always gain something. But from there:

If your turbo is really small then fitting a larger one helps power by shifting the best efficiency point higher.
Great if you're building a dyno queen. But 4wd's need low end torque.

If you turbo is really big and struggles to make boost and control EGT's then going smaller on the turbine side is needed to get it spinning and pumping enough air.
Going too big on the compressor side can backfire. Compressor surge is the result of trying to get more boost than a compressor can handle at low flowrates, if you fit a big turbo to a small engine it's a very real risk. The downsides are rooted turbo compressor blades flying off into your engine.

Compound turbos are a great solution if your engine can survive.

[Lucus]

Its usually fairly easy to produce more power on the less or the same boost with a larger turbo. It would be good to compare the a/r ratio of the mitsi turbo and the stock turbo. The larger turbo (assuming it is larger) will move a larger mass of air at the same boost pressure and will heat the air alot less in the process.

Reduction in exhuast restriction with a bigger turbine housing usually helps peak power, but this can also cause increased lag.

If the modded turbo runs an upgrade compressor and a near stock sized turbine you would normally get a increase in power with out a change in boost. You can also get a reduction in lag dependant on the design on the compressor. A large compressor and standard turbine can also cause and increase in lag due to the larger mass of the compressor.

Any body know the specs of the MTQ turbo vs the Standard turbo?

For what its worth i have dealt with mtq alot through work and they also rebuilt a turbo off my mates xr6t and they produce high quality work and have great customer service. (some of the turbos we send them are worth $35k to replace.)

cheers
Luke

[Dougal]

Its usually fairly easy to produce more power on the less or the same boost with a larger turbo. It would be good to compare the a/r ratio of the mitsi turbo and the stock turbo. The larger turbo (assuming it is larger) will move a larger mass of air at the same boost pressure and will heat the air alot less in the process.

I agree with much of the rest of your post, but not what is written above.

You can't compare A/R ratios between turbos directly, you can only do that for the exact same sized turbine wheel. Otherwise multiplying the A/R ratio by the exhaust wheel radius will give an effective flow area which can be compared across turbo brands and sizes.

A larger turbo will not heat air less and will not flow more air at the same boost.
Turbo compressor maps are quite simple and show efficiency based on flow and boost. This efficiency is the main driver in turbo outlet temps and bigger turbos are not more efficient than smaller ones.
The only way to flow more air at the same pressure is to run it cooler, as I've said above bigger turbos don't run cooler so can't flow more air for the same pressure.

The reason bigger turbos can provide more power at the same boost is because they cause less of an exhaust restriction. It's not a case of more airflow (most of our turbo engines have minimal valve overlap), it's a case of lower parasitic power loss.

But small turbos are quite capable of delivering the goods. I'm running a T25 with a 0.49 A/R exhaust housing on a 3.9L Isuzu. Below 1800rpm it is capable of delivering the same boost as backpressure. 20psi each side if the exhaust temps stay above 650 deg C.
This is with a restrictive exhaust (2 1/4") and ugly crossover piping. It potentially can do much better. Yet many wrongly claim a turbo like this is far too small and creates too much backpressure.

[Lucus]

I agree with much of the rest of your post, but not what is written above.

You can't compare A/R ratios between turbos directly, you can only do that for the exact same sized turbine wheel. Otherwise multiplying the A/R ratio by the exhaust wheel radius will give an effective flow area which can be compared across turbo brands and sizes.
you are spot on my mistake. I would be interesting to compare complete specs on both turbos. I was over simplfiying

A larger turbo will not heat air less and will not flow more air at the same boost.
Turbo compressor maps are quite simple and show efficiency based on flow and boost. This efficiency is the main driver in turbo outlet temps and bigger turbos are not more efficient than smaller ones.
The only way to flow more air at the same pressure is to run it cooler, as I've said above bigger turbos don't run cooler so can't flow more air for the same pressure.
In an application using the correct sized turbo you are again correct. If we are talking winding the boost of a stock turbo up and out of its efficiancy range then switching to a larger turbo will provide more power on less boost and a cooler charge at the same boost. Once again i could have explained that better

The reason bigger turbos can provide more power at the same boost is because they cause less of an exhaust restriction. It's not a case of more airflow (most of our turbo engines have minimal valve overlap), it's a case of lower parasitic power loss.Debatle topic this one as i have personally seen a .56 ar compressor housing (76mm wheel) switched to a .70 compressor housing (82/3mm? wheel memory is a bit hazy on this one) deliver apporx 35 extra kws on the same boost it also moved the max boost rpm point up aprox 1000rpm.The Exhaust housing wasn't changed. Not exactly ideal for a diesel. You are dead right tho a bigger exhaust housing will flow more giving less parasitic loss

But small turbos are quite capable of delivering the goods. I'm running a T25 with a 0.49 A/R exhaust housing on a 3.9L Isuzu. Below 1800rpm it is capable of delivering the same boost as backpressure. 20psi each side if the exhaust temps stay above 650 deg C.
This is with a restrictive exhaust (2 1/4") and ugly crossover piping. It potentially can do much better. Yet many wrongly claim a turbo like this is far too small and creates too much backpressure.Again you right. I think a larger dump pipe, larger and smoother intake ducting and a larger and higher flowing cooler would be a better option than dropping a modded turbo onto a 300tdi. Wastegate porting may also be a good idea to restore some boost control

[Dougal]

I think a larger dump pipe, larger and smoother intake ducting and a larger and higher flowing cooler would be a better option than dropping a modded turbo onto a 300tdi. Wastegate porting may also be a good idea to restore some boost control

It looks like we're on the same page afterall.

I have seen dyno graphs which showed a 200 or 300 tdi (can't remember which) boost level throughout the rev range. It looked like it dropped significantly getting toward the top of the rev range.
Simply finding the reason why and dealing with it will unlock a lot of horses, but at what cost to the low end?

[Lucus]

Thats the age old compromise of turbocharged cars. Top end thrust or low down torque?
I would assume the top end nose over over in boost would be caused by exhaust restricion choking it off.

I spose it could also be down to stock fuel timing/delivery and possibly cam shaft design too. Mind you, you couldnt go past a better intake system.

[rick130]

JustinC has fitted a few of the DTS kits and reports that they work well.
Do a search, we've discussed this a bit in the past, including comparing the VNT off the 2.8HS.

When I've discussed the TD04 vs the GT250 MTQ tell me that their setup is more efficient with lower outlet temps.
They use a newly cast centre piece of the exhaust manifold with re-machined end cylinder pipes, with these bits off your original setup returned on an exchange basis.

I posted the dyno graphs of both systems only a few days ago on another thread.