Holset HX40 vs GT3076R

[Billman]

I thought you might find it interesting as i did and thta why i am sharing it with you:



"hx40 vs gt3076r dyno sheet this is on a 2g dsm. My friend let off cause of some problem......its a dsm need i explain"

Hx40 left 3076r right


"Judging by the graph the HX40 had nearly identical spool up to the GT3076R (which is known for its excellent response)"

here is the original post:

http://turbobyholset.com/forum/hx35/hx40-vs-gt3076r-dyno-sheet/

[quattro84]

Billman don't share this kind of info, the Holset prices will go up...

[GT500]

Fancy a HX35 for the 2.0 tfsi I'm sorting.

Big enough?

[Billman]

depends on the comp wheel and turbine housing you choose

[A80Avant]

yes, this is one of the posts that got me to try the HX40 in the first place. BUT without the proper setups on the turbo, the results can be misleading.

for example:

which GT3076R? 0.63/0.82/1.02AR?
Which HX40? i presume the 0.55AR according to the picture.

If i believe the graph was with the 0.82AR vs the above HX40, then i can now understand the results, as the HX40 would be easily be more powerful as it has a larger compressor wheel and better design.
However if the Garrett was with the 0.63AR, then the HX40 is better in spooling and power.

Fit the HX40 with the 0.70AR and the difference is huge and my experience is 1st hand and undoubtfull.

So my advice would be to either use the 0.55AR from US OR find and modify a K26 as Billman did. Otherwise the turbo will be never like a 0.82AR 3076 in spooling, no matter what you do.

By the way, the bullseye hotside 0.70 is also quite thin and the V belt of not so good quality. At least the tial ones dont leak exhaust fumes and mine did quite a bit and needed a lot of paste to get it to seal properly.

[Billman]

From the housing dimensions I believe that this Garrett has 0.63 housing. The holset in the picture has a 0.55 for sure.

If it is that way then it would mean that the turbos are on the exhaust side similar (Garrett smaller turbine impeller but bigger Housing AR, holset larger turbine impeller but smaller housing AR).

Right now I have in 4. Gear with the stroker 1 bar at 3700-3800 with a 16ccm holset housing (according to sites it corresponds to an AR of 1.13 but on a hx35 turbine impeller witch is smaller than the hx40. :-D
Note: mapping is not perfect yet so maybe the lag will be reduced.

[A80Avant]

i cannot really tell if this is 0.63 or 0.82AR just from that picture and i have seen both in real life. So judging from the photo is not ideal.
Again, i was expecting the same as you suggest, ie. bigger AR but smaller impeller would be equal to larger impeller and smaller AR. It is not.

I used to get 1.7bar on 3d gear on the HX40 @ 4700rpm roughly, and on the GT3076R i have that at 3900rpm. In Holset's defence i didnt try more than 1.75bar. HOWEVER what was shocking was that on 4th and 5th gear, the difference in reaching higher boost was not really much different, whereas the garrett gets much faster there. In 4th gear, i had 1.55bar @ 4400 on the holset, while i have that at 3500rpm on the garrett at least. This is what made the turbo unworkable for me and the everyday use of the car.


also, dont forget you have a stroker as well.

Im not saying holsets are bad, but for our engine, they need their tweaks to get them to work nicely

[Billman]

They need good matched turbine housings for the application.

You had a 65mm turbine exducer with a 0.70AR housing on the Holset and a 58mm with 0.82AR on the Garrett. The second one flows less than the first. Holset goes till 650 hp while Garrett to 550??
GT3076R is Turbine side wise much smaller (60/55mm turbine inducer/exducer) than the hx35 70/60mm turbine wheel). Hx40 is a whole step bigger than that (75/65mm). The hx40 has 1cm bigger turbine wheel than the 3076 and that is massive.

I am going to prove my point if I found another housing I am searching for my holset. If i do, i will go from 60mm turbine exducer 1.13 AR to 60mm 0.89 AR without having to change anything else on the exhaust.

Garrett data found here

http://www.xcceleration.com/turbos.htm

[A80Avant]

there is no doubt about the holset being more powerfull turbo.there is doubt foe me for 2 things: one being the lag and the other being the amount of hp it can produce when you have to use so small turbine housings. i will remind you that no matter the bigger turbine wheel or ar on mine, and with 1.7 bar, i was getting already quite high egt.

[Billman]

Turbo discussion....i love it

For your EGT i think the problem was somewhere else....maybe timing....
With the machined K26 (with a nr. 6 neck it is somewhere near 0.55 AR) i was getting no more than 820 right after the turbo with 1.7 bar from 3500 to 7300.
As for lag, if i had the money i would love to do 2 different dyno sessions one with the first housing and one with the other.

[Thuppu]

Here in Finland HX35 Super and HX40 Super is quite popular turbos. No doupt they are great turbos. Here is some holset maps: http://jysal.pp.fi/hx%20kartat/

[A80Avant]

timing was and is identical.more and less also tried at the time without any good effects

[GazzaG60]

its a trade off. i make the presumption that a 4k spool holset will boost into the higher rpmj bracket and make more top end than the 30 76. if it doesn't then junk it.

turbo = compromise.

that spool you talk of is similar to my 0.63 stage 5 sc61

[A80Avant]

excactly that Gary,its just that Billman feels that a holset can have the samw lag as a 3076 and much more hp at same boost levels, which from my experience will be very hard to prove.Holsets are great tuebos but a more appropriate comparison would be a hx35 to a 3076.

[Billman]

HX35 is 5mm bigger turbine impeller than 3076. the holset equivalent to 3076 is probably HX30. However, i am going to prove you Vasilis that with a GT35R equivalent HX35/40 hybrid i will have the spool you get with GT30R.