Z32 Vs Q45

[Josh...]

I know z32 is tried and true but the q45 is a 90mm ? Which are better ? I've heard z32 has more resolution even tho it's a smaller body ??

[The Mafia]

There are clones or dodgy ones out there. Mine wasn't.

I have used a Q45 with my powerfc for years. At 315rwkw it was no where near being maxed out. I was running a GT3076 at 18-22 psi. I'd say it had about 380 - 400rwkw in it.

The benefits are that it has a larger diameter which means less restriction.

My turbo had a 4inch inlet, and I didn't see the point of reducing to a z32 size, so I bought the Q45. Was very happy with the results.

its for sale if you want it. Car was parted out and it was running my RB25\30 before we took it apart. Has the Plug and all. Let me know if you are interested.

(Im a tuner too... so I did all the tuning etc and I can guarantee it worked 100%)

Edited November 29, 2011 by The Mafia

[Legionnaire]

I know z32 is tried and true but the q45 is a 90mm ? Which are better ? I've heard z32 has more resolution even tho it's a smaller body ??

You sure you are not confusing resolution for maximum measurable airflow? Generally, the higher the max flow, the lower the resolution.

Being an AFM for 4+ litre V8 one should expect Q45 AFM to have poor resolution, particularly at low rpm, but this is not a big concern on a RB25.

As for which one is better - it depends on what turbo you're going to use. If it's something small, say, hypergear bolt-on proposition, then I'd say stick to Z32 AFM. If it's something big, and with 4" inlet, then you could really benefit from higher ID AFM, so Q45 is a good candidate. It also depends on who will do the tuning.

Mafia, what P/N does your AFM have, is it -61U01 or -61U00? 4-contact plug?

[Josh...]

Legion as you would know from my other many recent questions it is indeed a hyper gear turbo :-) it just seems that you can get the q45 for much less than the z32 and i know I won't max out a 32 with the hyper gear but I may upgrade turbos later...... Would there be any downfall to using the 45 now incase i upgrade later ?

[JonnoHR31]

spend the extra $100 tops and get a brand new genuine z32. support more power and have a more linear voltage scale, which makes light load tuning and therefore economy better. if you making enough power for a 3" afm to be a restriction then your past the point of being able to use afm's anyway.

[Legionnaire]

Brand new the cost is roughly the same for either one, and JonnoHR31, although I somewhat disagree with the last sentence in his post, makes a very good point about easier low load tuning and economy. The limit of the Z32 AFM is approx. 580 bhp, and its ID is rarely a major restriction, as it has been proven by lots of results in RB25 dyno thread.

[The Mafia]

I never had any issues with low load tuning with my q45.

[Legionnaire]

What AFM exactly do you have though, that's the question. These is another member here, his nick is Dangerman (or something like that), he had RB boosted by GT35 and mass flow measured with q45 AFM, he was quite happy with his AFM, but there was a bunch of other dudes who had no luck with Q45 and reported them to max out at roughly 270wkw.

So it would be nice to know if ther is a distingushing feature, an indication that would allow us to tell a higher reading AFM from an ordinary one.

Dangerman's was brand new, had a four pin plug and a P/N 22680-61U01. What's the P/N of yours?

Quick internet search informed me that there are Q45 afms, both with yellow sticker but with 2 slightly different P/N's, one's -61U00 and other is -61U01. The first one has 3 pin plug, the latter has four pins and that's the one Dangerman used. That makes me suspect that -61U01 may be the higher flowing AFM, and U00 is the "bad" one.

[R32Abuser]

IIRC I have the 3 Pin plug version of the Q45 AFM on my RB25/30 with a GT3076R.

Making 256 RWKW (some power issues up higher in the rev range) with no issues down low regarding "resolution".

I have been told by my tuner that I have plenty of AFM left to work with and we are FAR from maxing out this AFM.

Once I get my car back (today) I'll post my P/N as a reference.