Will the bigger VNT15-49 and manifold bolt on?

[AtomicSushi]

I got my hands on a GT1749V and manifold from a PD115 for pretty cheap and was wondering if the exhaust manifold would just bolt right on in place of the ALH one?

 

[oldpoopie]

good question... I'd like to know too!

 

[Lord_Verminaard]

Cool! Where'd you get it? And for how much? It should bolt on without a problem, but the vacuum lines may be different, I dont know. Keep us updated!

Brendan

 

[cage]

What is it? Wouldn't a bigger turbo be a slower turbo?

 

[AtomicSushi]

Its a VNT15 still, but its the one with 49mm vanes.
The 115PD's use them. I expect slightly slower spool up but better boost making ability at 18 pounds where I plan to run it. I also expect it to work better with the forge FMIC I plan on getting when it goes on sale (endtanks top/bottom both exits on the passenger side near the stock intercooler. Additional piping over to the Dieselgeek intercooler pipes should be trivial.
I do NOT have the compressor maps for this to compare with the VNT-1546 we have. Anybody know where I can get the map?

 

[wyseguy]

I have had this turbo on my car, as it cam eon my new engine, for 20,000 miles now. I can't say I notice a huge difference over the 46mm one. It bolts right on, and the vaccuum lines are the same. The only difference in the setup is the actual turbo cartridge that bolts laterally to the exhaust manifold and integral turbine housing.

 

[AtomicSushi]

Would I be wasting my time installing this?

 

[Eric Maurier]

My ALH engine came with a GT1749V. So you shouldn't have any problem fitting it in, but I don't think you're going to gain much with this mod. A stock ALH has already more than enough air available, all you need is more fuel.
BTW parts catalogues say the turbo on the newer AJMs is the same as on the ALHs.

 

[Lord_Verminaard]

My ALH engine came with a GT1749V. So you shouldn't have any problem fitting it in, but I don't think you're going to gain much with this mod. A stock ALH has already more than enough air available, all you need is more fuel.

I disagree. (I think!)

We can fuel these cars out the wazoo, it's getting CFM to the engine that is the problem. Sure, the vnt15-47 can hit 18 psi but wont flow as much cfm. The vnt17 would be ideal. (hence the 150pd engine uses it) But I say bolt it on. You'll gain some hp at least. If anything, you'd be doing some research for all of us!

Good luck.
Brendan

 

[Eric Maurier]

I disagree. (I think!)

No, it's just that we don't have the same definition of "stock". By stock I mean not only stock air intake, but also stock injection system, ie no chip or injectors or evry mod. In that case, no matter how much air you flow in there, should you use a VNT 19 or 25 or pressurized liquid oxygen

you will not make a single more HP, because the torque map in the ECU will prevent you from getting enough fuel.
Now if you have a modded injection system (which is AS's case, I should have checked that sooner) with a "stock" intake and put in enough fuel to have some unburnt, you indeed need more air in there. The question is whether going from a little VNT-15(GT1747V) to a bigger VNT-15(GT1749V) will help you much. It's possible the somewhat bigger VNT-15 will withstand high levels of boost more reliably, but if you put any value to your time, you should go with a VNT-17 from the beginning. All this also implies you modify the requested boost from the ECU, else this is completely pointless.

 

[Lord_Verminaard]

Now if you have a modded injection system (which is AS's case, I should have checked that sooner) with a "stock" intake and put in enough fuel to have some unburnt, you indeed need more air in there. <font color="blue"> *snip* </font> All this also implies you modify the requested boost from the ECU, else this is completely pointless.

Right. I should have been more specific.

Anyway, we dont even have a "real" source for vnt-17's yet... if we did, then of course there would be no point to put the larger version of the VNT15 on there, but if he got it for a good price then by all means, slap it on there!

Anyone know where to find a VNT17 in the states for cheap?

Brendan

 

[AtomicSushi]

Thanks for the info. While I'm sure this isn't as good as a VNT17, I'm going to go ahead with the swap. Our blocks can't really handle the 22PSI the VNT17 likes to run at, so for 18-19 PSI sustained I think this bigger VNT15 is a closer match for the boost level I want to use.

 

[AtomicSushi]

So the turbo is on its way from England.
How much bost does a stock PD115 run? I want to be extra careful I don't blow this one up.

 

[Eric Maurier]

Around 2.1 bar absolute.

 

[AtomicSushi]

Thanks.
Anyone know what max safe is?
I expect to run this at 18PSI

 

[AtomicSushi]

Will the bigger VNT15-49 and manifold bolt on?

Yes. Its on my car right now running stock boost. It will be tuned up to 18PSI when the Dieselgeek IC pipes go on (boostgauge disconnected for now).

I still need the MAP for this one vs the stock one. I'll e-mail them, but I don't know if Garrett would respond if I just e-mail them and ask.