Reducing the IQ in the software, you mean the mapping or via VCDS or the hammer mod?
What would be the benefits of the bigger nozzles if i have to lower the fuelling, shouldn't i just use smaller nozzles?
ALH turbo upgrade question
- Thread starter wauwau
- Start date
What would be the benefits of the bigger nozzles if i have to lower the fuelling, shouldn't i just use smaller nozzles?
adamss24
Veteran Member
The benefit of larger nozzles is headroom and better atomization into a shorter window ! The power is addictive and you get used to it, best to have fueling sorted in the tune than having to go trough the swapping of injector nozzles all over again when you’re bored of the power !
Mongler98
Top Post Dawg
- Joined
- Mar 23, 2011
- Location
- COLORADO (SE of Denver)
- TDI
- 98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
thats not how it works. you are moving the fuel map by shifting the cam on the QA. NOT changing how much fuel it gets, just when it gets it. kinda..... its complicated. Just know if you DO NOT raise the QA on bigger nozzles with out an EGT gauge and boost to back that fuel map up... you WILL have EGTs that can and will destroy the turbo in just a second.
If i understand correctly, if i take my current fuel maps and multiply them with 0.83 wouldn't i get nearly the same amount of fuel with 0.260 nozzles? Just trying to understand mappings. So, with bigger nozzles, would it be possible to alter the SOI and the Injection time, becuse more fuel is delivered in the same time?
PakProtector
Veteran Member
Hmmm...I like to look at the extremes; book-ending a question so to speak. I am fairly sure with a big enough pump/injector set up one could have a 'nominal' SOI, and deliver enough fuel fast enough to burn the edges of the bowl. Not sure where this lies on the spectrum, but I suspect it is near one end. The other end is pointless to look at as it involves long duration and small injectors...
I would think a slightly expanded pilot injection event, starting from something like factory acceptable specs would be useful...then dump in the rest quickly and from higher pressure. The 'the rest' happening whilst it is least likely to impinge on the bowl edges.
Douglas
I would think a slightly expanded pilot injection event, starting from something like factory acceptable specs would be useful...then dump in the rest quickly and from higher pressure. The 'the rest' happening whilst it is least likely to impinge on the bowl edges.
Douglas
MAXRPM
Veteran Member
No oil restrictor needed, GTDs turbos are great, you can have your cake and eat it with these turbos,
muchboost.com
BigTurboDiesel – Muchboost.com
muchboost.com
MAXRPM
Veteran Member
Pakprotector im still waiting for you to pull the trigger on the GTD turbo, man you've been mentioning about getting this turbo for years, you just dont know what your are missing, the ALH got all sweet spot with this turbo, mine is still running strong and ive never got bored of driving my daily Driver with the GTD, what a nice turbo, ALH should've come with this turbo to begin with.
david mihai
Member
I was driving GTD1756VRK mounted in 1.9TDI BLT engine before I put GTD2060VZ. The results were impressive, quick spool. I think it`s perfect as a 'daily turbo'.
5000 miles later, i am very happy with the 1752 turbo. I wrote my own mapping from scratch and after fitting a lift pump, i'm totally satisfied 
Only dissapointment wasi had to replace my clutch with a SachsPerformance.
Only dissapointment wasi had to replace my clutch with a SachsPerformance.Judson
Veteran Member
I went with the 1752vrk as well. Love it. It’ll do 28psi and honestly this is an older engine and I wouldn’t want to run more. Besides, after a bad N75 destroyed two turbos on me before I caught the problem I am quite gunshy with respect to even going that high.
More than enough power to go up and over the mountain passes here out West.
The reason I didn’t go larger on the turbo was that I wanted stock-like boost response and at that time everyone was saying that even starting with the 1756 there was a bit of lag which only got worse as you went larger. People have posted here since that this doesn’t match their experience. But I can tell you the 1752 has zero lag. Can’t tell it’s not factory.
More than enough power to go up and over the mountain passes here out West.
The reason I didn’t go larger on the turbo was that I wanted stock-like boost response and at that time everyone was saying that even starting with the 1756 there was a bit of lag which only got worse as you went larger. People have posted here since that this doesn’t match their experience. But I can tell you the 1752 has zero lag. Can’t tell it’s not factory.
i'm also around 1.95bar at maximum boost, i need a 4bar map sensor now, because sometimes i get a little overboost on a gear change and the ECU cuts the turbo. I'll will change to 4bar map when i install a new intercooler. Car is smoke free, till i reach 3000rpm at WOT.
@Judson
Does your car smoke?
@Judson
Does your car smoke?
Judson
Veteran Member
My car produces a bit of smoke on WOT. Not a ton. I have a Eurojet intercooler, a 4bar map, the vented fender liner, and the bumper vent on that side.
Last edited:
ecala001
Veteran Member
what size silicone inlet pipe did you use to make it fit the stock alh inlet pipe? as for the exhaust side will it work on a 3" inch downpipe with the 3 bolt flange work even though it is 2.5"?
MAXRPM
Veteran Member
On top of my head I do not remember, I used the old OMI then I measured the OD from turbo and order the elbow to hook it up, yes you can do a 2.5" to 3" flare out at down pipe, I'm running 2.5 " with Gtd1756vrk, for me was very much plug and play with the exception of 2 elbows then just welding a 2.5 ring to down pipe neck, and everything else fitted like a glove
FoX
New member
Im doing exactly what you all are doing now.. On a BEW. OMI tube from kerma .. does the elbow fit onto the 2.5" inlet on the gtd1752vrk?
Planning on the 3" kerma exhaust and just cutting old GT style flange off and welding on a v band to mate with turbo..
Got a Darkside upgraded side mount with vented inner liner, going with BEW injectors w/ pd150 tips, and a SBC stage 3 daily
Since you all have done this .. please throw out the recommendations! Would be greatly appreciated!
PakProtector
Veteran Member
You are exactly right there Max...I am waiting too...LOL I assume that when I am about a week from sending the $$$, somebody will turn up a 50k mile ALH manual from well south of the Salt Zone...
Douglas
Douglas