Before vs After CSL+ Spec Engine Build

[GT Spec]

Hi all,

I thought I'd share my recent experience of the engine works I carried out over the past few months and to inform you of what to expect if you go down a similar route.

I bought my low mileage (28k) E85 M back in 2020 with the aim of modifying the engine to CSL+ specification. I took the car to my local respected rolling road (Maha/TAT) to do a power run in standard specification and it made a predictable 321.5 crank bhp; the rolling road chap said the power figure was totally expected in his experience with the S54s he had dyno'ed over the years.

Since buying the car I was lucky enough to acquire a set of Schrick 288/280 duration camshafts, Schrick finger rockers, Karbonius carbon fibre race spec airbox, ITG foam air filter, ARP head stud kit and full Supersprint exhaust including the 100 cpsi cats.

When installing all the parts I decided to remove the cylinder head and take it for Hack Engineering for inspection. Whilst there I was convinced to replace the valve guides for ones manufactured from a superior material and to a tighter tolerance. Also whilst the cylinder head was off I decided to 'bulletproof' the VANOS unit by fitting the uprated Viton seal kit and the uprated upper timing chain guide for Beisan Systems items.

Once the engine was fully rebuilt I reached out to Josh at Severn Tuning to provide the alpha-N ‘tune’ for the stock MSS70 ECU. I was very impressed with Josh and would recommend his services in a heartbeat, he is really knowledgeable about the MSS70 ECU and was super responsive in his approach with me. The 'tune' was developed from live on road data logging and a final dyno session.

So the results:

Before
Power 321.5 bhp @ 7999 r/min (239.74 kW)
Torque 253 lb/ft @ 5021 r/min (343.1 Nm)

After
Power 367.3 bhp @ 8015 r/min (273.9 kW)
Torque 257.6 lb/ft @ 6639 r/min (349.3 Nm)

An increase of almost 46 BHP at the top end and no noticeable losses down low in the rev range.

Hope that is useful info

[brillomaster]

Very impressive! that'd be a riot on track where you rarely drop below 5k rpm.

[beanie]

Awesome, I’ll bet that’s a joy to rev out.

Like yours, mine made 325bhp as standard and my only criticism of the stock engine was the power tailing off at 7k. Easily remedied and once fixed, makes the thing really charge to the limiter.

[Ed Doe]

Precisely what I'd like to do with mine - lovely job and nice results!

I don't suppose you'd mind pm'ing me what sort of cost was involved? I've already got the Schrick DLC followers, so I'd just be fitting the cams which isn't a head-off job fortunately, but yours would be a good steer for me in terms of working out what I need to put aside! lol

Cheers

[GT Spec]

Precisely what I'd like to do with mine - lovely job and nice results!

I don't suppose you'd mind pm'ing me what sort of cost was involved? I've already got the Schrick DLC followers, so I'd just be fitting the cams which isn't a head-off job fortunately, but yours would be a good steer for me in terms of working out what I need to put aside! lol

Cheers

PM'ed mate

[enuff_zed]

Very impressive! that'd be a riot on track where you rarely drop below 5k rpm.

Yes very nice work, if you are going to track it.
But for road use you have only gained a tiny bit of torque and moved it up the rev range a fair bit.
I accept that the graph shows an increase below that too. Very odd how it dips around the 5-5.5k rpm range?

You've taken a race engine and made it a RACE engine.

As a comparison, my mapped 20i N20 makes more torque at 1500rpm than your max figure, and it is basically a flat line from there to 6500rpm.
So on a bog-standard British road I'd be quite happy, if I could accept that my car sounded shite compared to yours.

On a track though.................... I'd need a zoom lens on my dash cam to see where you went.

[B21]

Good write up..interesting to see the combined effects of cams and induction mods…would have been interesting to see the effects of the individual items..but not so easy…good result..

[Ed Doe]

Comments like that just remind me of the perennial turbo diesel vs gti6 debates on the old Peugeot 306 forums I used to frequent. I was initially a proponent of the turbo diesel 'yeah but mine has nearly double the torque so I'll be quicker in real life on a b road' argument. Spent years tuning the things up, popping turbos etc.

And then I got a gti6. And suddenly I got it. I'm sorry but the only advantage of having lots of torque in the real world is on the motorway when you're too lazy to stir the box for a more optimal cog. On any road where you're concentrating on driving, which is ultimately what most are doing when they're out driving their sports car, that whole argument doesn't matter.

Fwiw I personally think it's a testament to the design of the engine (vanos etc), and the mapper that you've put lumpy cams into an engine already putting out more than 100bhp per litre, and still retained almost identical torque figures in the low/midrange.

Also don't take this as an argument starter or a slag off of other models of z4, what is possible on the later 2.0 turbo engines is mighty impressive. It's just a bit of a moot argument talking abow low end torque IMO!

[enuff_zed]

Comments like that just remind me of the perennial turbo diesel vs gti6 debates on the old Peugeot 306 forums I used to frequent. I was initially a proponent of the turbo diesel 'yeah but mine has nearly double the torque so I'll be quicker in real life on a b road' argument. Spent years tuning the things up, popping turbos etc.

And then I got a gti6. And suddenly I got it. I'm sorry but the only advantage of having lots of torque in the real world is on the motorway when you're too lazy to stir the box for a more optimal cog. On any road where you're concentrating on driving, which is ultimately what most are doing when they're out driving their sports car, that whole argument doesn't matter.

Fwiw I personally think it's a testament to the design of the engine (vanos etc), and the mapper that you've put lumpy cams into an engine already putting out more than 100bhp per litre, and still retained almost identical torque figures in the low/midrange.

Also don't take this as an argument starter or a slag off of other models of z4, what is possible on the later 2.0 turbo engines is mighty impressive. It's just a bit of a moot argument talking abow low end torque IMO!

Then our opinions will just have to differ.

[1536Z4]

I thought I'd share my recent experience of the engine works

Haven`t got an M but love reading write ups like this

[B21]

Comments like that just remind me of the perennial turbo diesel vs gti6 debates on the old Peugeot 306 forums I used to frequent. I was initially a proponent of the turbo diesel 'yeah but mine has nearly double the torque so I'll be quicker in real life on a b road' argument. Spent years tuning the things up, popping turbos etc.

And then I got a gti6. And suddenly I got it. I'm sorry but the only advantage of having lots of torque in the real world is on the motorway when you're too lazy to stir the box for a more optimal cog. On any road where you're concentrating on driving, which is ultimately what most are doing when they're out driving their sports car, that whole argument doesn't matter.

Fwiw I personally think it's a testament to the design of the engine (vanos etc), and the mapper that you've put lumpy cams into an engine already putting out more than 100bhp per litre, and still retained almost identical torque figures in the low/midrange.

Also don't take this as an argument starter or a slag off of other models of z4, what is possible on the later 2.0 turbo engines is mighty impressive. It's just a bit of a moot argument talking abow low end torque IMO!

I think we all agree the tuner has done a great job on exploiting the h/w and it does show the benefit of VANOS, probably even more ironically than on the stock tune.

As for the turbo vs NA and auto vs manual debate each to their own.

We all derive satisfaction from these cars in different ways, noise, feel, dynamics, sound etc and how they respond to your inputs and other factors.

I think it’s disingenuous to suggest that the only benefit of a fat torque curve and maybe implicitly an auto box is a bored driver on a motorway.

I get completely the pleasure in a few well timed runs up and down the gears.

Where (for me) the novelty wears off is on multi day events where you are covering 200-300 miles over A/B/C roads.

I see my NA manual chaps looking pretty shattered..they’ve enjoyed the day but they are tired and you can see their ‘performance’ deteriorate during the afternoon…my turbo’d / auto device allows me to arrive relatively fresh whilst easily keeping up with them , or if I’m leading stretch out in front.

It’s a specific set of circumstances..which happens to be my main use of my car..

If I was track day warrior I’d maybe look at it differently.

I doubt I’m going to convince anyone on the merits of this argument…

[Ed Doe]

I do appreciate the other side of the argument of course, ultimately like most things it's horses for courses isn't it. Appreciate the well mannered discussion on the subject, we should probably leave it at that as I don't want to detract from the op's thread!

[GT Spec]

Thanks all for your input. The purpose of the post was to inform those who want to go down a similar path of the likely result. I had toyed with the idea of going down the supercharger route but decided to stick to NA as it is the main appeal of the E85/6 M platform.

The car is a weekend toy and only used during the summer months so I wasn’t too interested in daily drivability plus I have kept all the factory parts to go back to stock if I decide to ever sell the car.

[Mr Tidy]

lt.

The purpose of the post was to inform those who want to go down a similar path of the likely result.

That was a really interesting read, so thanks for posting it.

Certainly something to keep in mind if my MC ever starts to feel a bit sluggish!

Like Ed I'd love to know what sort of cost I'd be looking at though if you didn't mind sending me a PM too.

[GT Spec]

lt.

The purpose of the post was to inform those who want to go down a similar path of the likely result.

That was a really interesting read, so thanks for posting it.

Certainly something to keep in mind if my MC ever starts to feel a bit sluggish!

Like Ed I'd love to know what sort of cost I'd be looking at though if you didn't mind sending me a PM too.

PM’ed