Holset Pro 52 questions...

[euro_urs4]

Hey guys, a buddy of my claims he has a pro52 for sale, I just wanted to see if you guys could answer a few questions for me before I pick this up.

I am currently running a Super 40 on my URS4.

-Is there a HX52 and then also a Pro52?

-How can i determine if it is really a Pro52?

-Did all Pro52 come with a billet wheel?

-Was a Pr052 a t4 or t6 flange?

-Any other input would be great! thanks guys.

[caterpillar]

have you more info: what A/R are the hot side and what inntake mm??

[euro_urs4]

No I do not have that info I'm am going to go take a look at it this Saturday, was seeing if there was anything to look for to make sure it's the correct one

[rst]

Here is some info of Holset Pro 52.

http://www.kkdmotorsport.com/kauppa.php?t=1270892685&k=1270835105

[diesel des]

900 to 1000 hp.....

[quattro84]

Forum member Kenax has one on his urS4.

From my head they utilize a #16 hotside similar from HX50 series with T4/Holset footprint, Compressor cover similar to HX55 but machined to fit 98mm impeller compared to 102 & 106mm for HX55. Not sure which turbine but i thought is was similar to HX50, HX50 turbine <-> HX50 compressor 67/98 seems to be a bad match for Otto engines so the Pro52 will be a better matching.
HX52 has a bigger lumpy turbine end if not mistaken but can be found cheaper because those were fitted to a lot of Renault/Volvo/Mack/... 13-16litre trucks.

[repo]

When pro52 came out, it was praised to be the most advanced turbo ever, with widest flow range available, and good for 900-1100hp depending on source.

Highest i have seen it to make is 800 and change with crappy torque. Original pro52 has way too small turbine wheel, smaller than compressor, so it just punches and fades with ton of lag.

I do not like Holsets, that is no secret, but along with hy35, pro52 is one of my favorite dislikes.

[kenax]

There are HX52's with three different compressors that I know of, 63mm, 65mm and 67mm and none of these is a pro52. Pro52 has a 71mm compressor impeller. To identify a real pro52, just measure the intake diameter, it should be around 71,5mm. The compressor casing is the same as in HX52. The standard turbine housing is a dual throat 16ccm T4 with exhaust port with roughly 71mm in diameter.

I'm trying to find out the capacity of this turbo in practice during this season, but so far I've dynoed only 830 and change with crappy 850nm of torque at 2,1bar. Later last year I tried with higher boost, and it made a huge difference. I've not had it dynoed so I don't know the real power output, but I'd say it's somewhere around 10% on top of the earlier 830hp, using 2,4bar boost. I have not seen signs of fading so far, time will tell when I run it higher and with more boost.

On another note, your antipathy against Holsets is a poor excuse to always flame them when a chance presents itself, Repo. I don't like religious people with zeal and you seem to be one. I'm open to other turbos as well, but so far this particular turbo does exactly what I need.

[repo]

I am not flaming. This dude asked for input. I gave some. Only Audi application with pro52, I have seen so far, was 815hp and 750Nm, and a LOT of lag.

You on the other hand are the Fastest Audist in Finland, so I beg Your pardon to dislike Your choise of turbo. You are 300hp away from the advertized capacity, so keep adding boost, I will keep waiting for results.