M52TU and ZHP Camshafts

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zielritter
Joined: Thu 11 Oct, 2007 04:18
Posts: 2

  Z3 roadster 2.3

M52TU and ZHP Camshafts

Post by zielritter » Mon 21 Oct, 2019 23:11

For those of you running the 2.5 or 2.8 M52TU motors, who has upgraded camshafts? The Shrick 248s are the obvious no fuss, if not pricey, upgrade. What about ZHP e46 cams? Are these a direct fit or would I need new valve springs or even a new head? The answers I'm seeing on forums aren't giving me a consensus.

TIA

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Southernboy
Joined: Thu 07 Oct, 2010 13:39
Posts: 6427

  Z3 roadster 3.0i
Location: Johannesburg

Re: M52TU and ZHP Camshafts

Post by Southernboy » Mon 25 Nov, 2019 07:36

Now here's a thing...
The M52tu intake cam can be directly replaced with the M54 3.0 or 3.3 cam.
This isn't as radical as the ZHP cam, but a heap cheaper.
The M54 exhaust cam is identical to the M52TU cam, so no point going there.
I have done the mod on my M52TU 2,8. It provides aprox 1mm more lift, but more importantly, it provides aprox 19 degrees more open time.
This mod, in conjunction with the upgrade to an M54 3.0 or 3.3 intake manifold will give you around 30+ extra ponies.
You will need a re-map to adjust the timing on the electronics side, and to balance out all the extra air coming in through the larger manifold.
You will need the 3.0 DISA which is a whole lot bigger.
The M54 manifold, has somewhat shorter runners, which will give you more top end performance at a slight cost of low rev performance.
However, with a re-map, you will find this can be minimised to the point where you will not notice any low end power losses. In fact you will still have better power down there than the OEM set up.
Have a look online regarding the difference in the OEM M52TU and M54 manifolds. It is immediately apparent that the OEM M52 Tu manifold intake runners do not match the cylinder head intake design. OEM M52 manifold has oval shaped runners where it connects to the cylinder head vs the D shape of the M54 manifold which is a direct fit to the OEM M52 cylinder head intake ports.
I didn't change the valve springs, and all is good.
The motor revs to the red line with great ease and in fact, when doing a re-map, you may also want to adjust the rev limiter up to around 8500.
The greatest appreciation of the added power etc. comes in at around 3000 rpm. This is also when the huge M54 DISA kicks in. Thereafter, the acceleration is strikingly obvious with the car hauling ass uphill with ease in 5th.
As an asid, and not that it makes any difference to the performance in a significant way, I had a whiny diff, and when I changed it with a replacement part, I could only find a 2.93 ratio in excellent condition. The OEM is 3.15. This means I lose low end pull away time, but I gain a higher top end. I don't race the car, so the top end is not important to me, however, the small change in rpm at any given speed, means I achieve a slightly better fuel economy.
I hope that gives you some food for thought in terms of achieving a significant power gain at a very reasonable price. I did both the intake cam and manifold conversions myself but I was fortunate to have the loan of the cam / timing tools from a mate. The entire conversion took me the best part of a day with stops for tea etc..
The final result of the upgrade is performance as good as, or slightly up on the 3.0 performance.
"Normal is overrated"
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zielritter
Joined: Thu 11 Oct, 2007 04:18
Posts: 2

  Z3 roadster 2.3

Re: M52TU and ZHP Camshafts

Post by zielritter » Tue 26 Nov, 2019 17:31

Southernboy wrote:
Mon 25 Nov, 2019 07:36
Now here's a thing...
The M52tu intake cam can be directly replaced with the M54 3.0 or 3.3 cam.
This isn't as radical as the ZHP cam, but a heap cheaper.
The M54 exhaust cam is identical to the M52TU cam, so no point going there.
Thank you for the very thorough reply. I actually already have done the conversion to an M54B30 intake manifold. I have that along with a full Turner pulley set, true cold air intake, headers, 2.5" exhaust, and the Shark Injector.

At this point I'm torn on what direction to go. The car is sentimentally valuable to me so I'm keeping it, but I'm not sure if I want to go forced induction or max out the NA mods (which will be more reliable). I have come more or less to the same conclusions as you presented when picking a cam option. I had looked at the Shrick cams, but they are 1300-1500 alone. The ZHP cams are more expensive than the normal B30 cams, but both are much, much cheaper than the Shrick. I still need a tune as well as the Shark is decent, but not once you start doing this stuff.

My tuner who helped with the manifold is going to give me some low-boost (5-8 psi range) options if I go that route. He's already recommended a new head gasket and fresh bolts as insurance if I go boosted. He also might have some ZHP cams at the shop lying around. He does almost exclusively BMW custom builds and works directly with Kastle for tuning. I'm going to pick his brain this winter and get into his shop soon. Not looking to make a Corvette killer out of my Z, but would like to get the power up a bit.

By chance have you dyno'd your M52TUB28 with your mods? I've read the similar 30whp gains as well, but most of the dyno sheets i've found are on the E46 forums. What other mods do you have?

PS - i'm going to be doing these power upgrades along with the RF reinforcement kit that's already sitting in my garage.

Thanks,
-Matt

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Southernboy
Joined: Thu 07 Oct, 2010 13:39
Posts: 6427

  Z3 roadster 3.0i
Location: Johannesburg

Re: M52TU and ZHP Camshafts

Post by Southernboy » Tue 26 Nov, 2019 20:14

I haven't done any mods to the power other than as I described previously. I haven't had a decent tune up yet, but as soon as my pocket can handle it, I'll get that done.
I have done the interior restoration. I bought the car as a project really cheap, but in poor condition. I re-upholstered the leather dash parts because the original had started to curl up with the South African sun / heat.
The floor mats are new too, and the entire interior plastic trim has been scrubbed clean and re-coated with a semi-matt black special paint.
I didn't like the OEM Walnut veneer console so I stripped the veneer off and replaced it with some beaut oak burl veneer I imported from the USA.
It's a really nice golden / light brown colour now with magic oak burl swirls in the grain. I finished it in a semi-matt polyurethane vs the high gloss. It looks a lot more classic in terms of the lack of gloss. Back in the day, wood veneer was finished with Shellac, which never had the super high gloss that can be achieved with urethane.
It has a new roof, new front tinted windscreen, and a heap of the mechanicals have been re-newed - brake discs, shocks, bushes etc etc. new engine mounts, water pump, etc etc.. I re-did the vanos seals at the same time I did the cam conversion. I had a center console cup holder CNC machined in the same look as the OEM plastic one which has become scarce and very costly. I had mine machined out of MDF and then gave it about 10 coats of polyurethane matt coating to seal it before I used the VHT 250 spray on black wrinkle paint. It turned out so well, that I'm looking at knocking out a couple of dozen. I added a special leather padded arm rest to the top of it which runs the length of the unit. It provides such a comfortable center armrest now.
Fortunately the car has no rust... Rust is actually a non-existent thing in South Africa if you're not in a coastal town. It's so dry here, that dust is more of a problem than damp.
The entire body paint was sanded down, re=primed and a new tripple coat of paint colour and clearcoat in the OEM Montreal blue. It has 18 inch narrow wides - all original BMW rims. 275 at the rear and 255 in front.
I replaced all the badging and bonnet grill trim with new. New fogs, re-polished the headlight lenses so they're clear like new.
So, a heap of cosmetic stuff. So mant small things like plastic clips that were lost or broken were replaced. Basically it is now in a fully restored, showroom condition. Since I live in Johannesburg, and at around 6000 feet ASL, I lose around 27% of the power I would get at sea level... So I'm not up much in real terms from OEM.. but I can sure as hell feel the extra 30 odd HP when I get down to the coast...
She holds a steady 210+ Kph without much effort up at Jhb altitude on the motorway.At sea level she's quite a different beast.. the M54 manifold plus the cam gives huge grunt and accelerating hard in 2nd will make the 275's spin on tar and get the ass wiggling easily.
Anyhow, you should have a pretty good idea of the car now..
I'll keep a watch out for your next post and any changes you make...
Barry
"Normal is overrated"
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