VT5 is on

[basstard]

Good luck with the car jason,,, you also got 8 spare hrs and spare time is best used for the ladies so try and see what you find around,,,

 

[shadowmaker]

I don't understand this,,, a too big compressor wheel limits the injection quantity? why?

Could someone explain this please?

So steve, you sayin that the compressor side of the VT5 is just too big for a 1.9?

I really don't know what to think. Will wait and see what happens when Jason takes the car to allards.

If mike is right allard should get big power out of the vt5 [which I hope for jason] and jabba isn't up to the business when it comes to diesel.

If steve is right then allard won't get much better figures than jabba and we'll know if their turbos are good stuff or not.

It'll deffo be interesting.

The compressor is creating too much flow than the engine can suck. At the same time turbine is too small to create force to keep compressor spinning against the pressure. This creates massive EMPs down low + pressure spikes against propellers. Not very healthy for the turbo.

To solve this you can make either compressor smaller or turbine bigger. Making turbine bigger is the only way for us to go as it will reduce EMPs at high rev range too. On the other hand it will weaken low end somewhat.

On VT5 it can be totally different thing, because even if it is a gt2256v, there are many variations of it. I personally suspect that a VT5 is way bigger just because on Mike's car there's really weak low end. As you can see on my friend's 1.9TDI there's 300Nm @ 2400rpm, which isn't that bad keeping in mind that fueling needed to kept low.

I still hope that someone can map those VT5 correctly, because there's always room for another fast diesel car...

 

[Triple D]

allards race car ran a vt5 turbo and that was running fine iirc, even won a few races last season........... so the mapingon that must have been fine

 

[devonutopia]

Their race car is a different kettle of fish - they don't go for all out power as the race series they compete in has strict rules on power, and they randomly take cars to be tested to ensure they're at/below the max BHP (I guess this is a little like Touring Car Champs?)

I've heard third party that Lloyd @ Allard really wants to get my setup right, which is encouraging for me. I just hope it can be done quick enough for me to get my sorry a55 back down to Bridgwater for a couple of runs on their RR.

 

[devonmikeyboy]

Whats TSR charge for a dyno run then mate?

 

[devonutopia]

I expect it will be circa £30? I don't really know.

 

[leegriffiths]

hope it goes well mate, cant wait to see it in action lol.

 

[shadowmaker]

allards race car ran a vt5 turbo and that was running fine iirc, even won a few races last season........... so the mapingon that must have been fine

At least they have some experience of it because of racing. That should make it much easier to map. Unfourtunately racing doesn't mean that it is suitable for everyday road use as it's not that important to have any low end grunt in a race car. Hopefully this isn't the case.

I once had my van setupped so that it started to pull from 3200rpm (with vnt) and max. torque occurred @ 4200rpm. Although power seemed to carry all the way to 5500rpm the car was really terrible to drive. This is why I decided to sacrifice some horses to have some comfort in my current setup. Fourtunately I need WOT very rarely nowadays...

 

[FabiaTDi]

My VT5 pulls well from 2000rpm upwards but is certainly less responsive lower down than the VNT17 which is not surprisingly given the bigger size of the VT5.

Mine has yet to be mapped but will be going in soon after Jasons.

 

[shadowmaker]

That's good to hear, because then there's a chance to make it even better with mapping.

Jason, can you measure EMPs? Atleast during mapping they should. This is the best way to tell what's going on there.

 

[devonutopia]

Electro Magnetic Pulses?

 

[Triple D]

exhaust manifold pressures

 

[devonutopia]

That's a new one on me. I have EGT temp gauge but nothing else which monitors that area.

 

[Triple D]

yeah i had a EGT gauge too, had the SPA Design one, was a tad exspensive but absolutly awsome, also had the boost with it aswell, 2 in 1 kinda thing

 

[devonutopia]

I have separate analogue boost (I love a needle when it comes to boost ) and a VEI systems EGT digital gauge from the States. Cost me little more than £60 in the end too, thanks to a good price and a good exchange rate. There's a thread on here with video of the gauge setup in my car I think?

 

[Triple D]

mine cost best part of £330

 

[shadowmaker]

Jason, trust me you need to measure EMPs. EGTs aren't that important.

Actually there's no way to map an unknown turbo without measuring EMPs. I thought this was clear to all.

 

[basstard]

shadowmaker, thx for the explanation in post #142.

now, how do you measure this EMP? do you have to drill the manifold and screw a sensor in?

 

[shadowmaker]

To measure EMPs is easy if you still have your EGR tubing intact. You just find a way to hook up your pressure gauge with it.

As I'm using custom manifold, there's a welded nipple with threads and 30cm long copper tubing attached to it. At the end of the tube there's a valve and a place to attach rubber hose into it. I'm not measuring EMPs all the time as the rubber might melt and there's no reason for it. I use it only on dyno as it gives information what's going on there.

You need to keep EMPs under 2,5bar, but best is to keep them lower than boost. This is rare over 1,8bar boost, but possible. Every turbo and every setup differs how EMPs behave.

 

[devonutopia]

Oh well, what about for someone with nothing remaining of his EGR?

In theory, could I setup another boost gauge directly to the exhaust manifold? I'd be worried about heat but could work something out possibly.