Z4 E85 N52B25 performance upgrade

Darkangelv2 · Post by **Darkangelv2** » Thu Oct 05, 2017 2:13 pm

Scarp wrote: ↑Thu Oct 05, 2017 1:50 pm and for the 2,5 liter there is no supercharger I contacted ESS like 4 times they only have a kit for the 3,0 . As far as I have researched for the N52B25 there is no supercharger available . I could install a shrick cumshaft taht would give me another 20-30 HP but thats more of a racecar mod then a normal usage fun car

The only sollution in my case can be swap to a N52B30 and supercharge it

I don't believe there is a Shrick CAM that fits the 3.0 N52 and definitely not the 2.5.

It's not in Shrick's catalogue, only on reseller websites. On those websites it has the same part number as the N54 cam so i think it's just being mis-advertised.

Darkangelv2 · Post by **Darkangelv2** » Thu Oct 05, 2017 2:15 pm

Chris1981 wrote: ↑Thu Oct 05, 2017 2:12 pm A big thing in the states they love is buying our N52 manifolds, We have two disa's giving the higher bhp figures. They don't have them over there I'm lead to believe.

This is the same as I've read in my research for more power out of the N52B30 (without spending £5k+ on a S/C)... the states have 325/328 that run a de-tuned version of our (UK) 3.0si, they all seem to switch out the inlet manifold for the one we get as standard! Using the inlet manifold is well known BMW trick for restricting power, pity is the 3.0si already gets the best BMW produce! Presumably fitting a 3.0si manifold to 2.5si will give a bit more power on the E85, good news for those on here with a 2.5si!

Curious as to how you get a dual DISA valve set up working on a car that's only designed to run 1 though... would you have to splice another connector into the ECU?
[/quote]

I don't think so as the 2.5si is a true 2.5L engine whereas the 325/328 in the US is a 3.0L with the restricted manifold as you say.

Smartbear · Post by **Smartbear** » Thu Oct 05, 2017 2:20 pm

Darkangelv2 wrote: ↑Thu Oct 05, 2017 2:15 pm
Chris1981 wrote: ↑Thu Oct 05, 2017 2:12 pm A big thing in the states they love is buying our N52 manifolds, We have two disa's giving the higher bhp figures. They don't have them over there I'm lead to believe.
This is the same as I've read in my research for more power out of the N52B30 (without spending £5k+ on a S/C)... the states have 325/328 that run a de-tuned version of our (UK) 3.0si, they all seem to switch out the inlet manifold for the one we get as standard! Using the inlet manifold is well known BMW trick for restricting power, pity is the 3.0si already gets the best BMW produce! Presumably fitting a 3.0si manifold to 2.5si will give a bit more power on the E85, good news for those on here with a 2.5si!

Curious as to how you get a dual DISA valve set up working on a car that's only designed to run 1 though... would you have to splice another connector into the ECU?

I don't think so as the 2.5si is a true 2.5L engine whereas the 325/328 in the US is a 3.0L with the restricted manifold as you say.
[/quote]

The uk 2.5si already has the “full power” inlet manifold, I think you must be thinking of the 2.5 non si model that’s about 170 odd bhp

Rob

Smartbear · Post by **Smartbear** » Thu Oct 05, 2017 2:30 pm

Even bmw’s Renowned M division could only extract 106bhp/litre from the mighty s54 engine with its bucket & shim valvegear and spinning the engine up to a stratospheric 8500rpm.
The n52 is acknowledged universally to be nowhere near as strong (the forced induction kits run low boost & they will not approach the rpm limits of the M engine) yet you say your remapped 2.5 produces approx 102bhp/litre while only revving to 7000rpm?
I’m amazed

Rob

Scarp · Post by **Scarp** » Thu Oct 05, 2017 2:47 pm

Here´s the dyno sheet

: 13327383_969992326448636_6371641669698678403_n.jpg (152.87 KiB) Viewed 1217 times

Smartbear · Post by **Smartbear** » Thu Oct 05, 2017 3:15 pm

Scarp wrote: ↑Thu Oct 05, 2017 2:47 pm Here´s the dyno sheet

13327383_969992326448636_6371641669698678403_n.jpg

That’s not extrapolated correctly?
Rob

Ducklakeview · Post by **Ducklakeview** » Thu Oct 05, 2017 3:51 pm

Scarp wrote: ↑Thu Oct 05, 2017 2:47 pm Here´s the dyno sheet

13327383_969992326448636_6371641669698678403_n.jpg

Looks like hard evidence to me!

Mike

Scarp · Post by **Scarp** » Thu Oct 05, 2017 3:59 pm

The other dyno run is on the video

same resault

Smartbear · Post by **Smartbear** » Thu Oct 05, 2017 4:04 pm

Ducklakeview wrote: ↑Thu Oct 05, 2017 3:51 pm
Scarp wrote: ↑Thu Oct 05, 2017 2:47 pm Here´s the dyno sheet

13327383_969992326448636_6371641669698678403_n.jpg
Looks like hard evidence to me!

Mike

The bhp & torque curves are supposed to intersect at 5250rpm, something is amiss with this graph.
Rob

Ducklakeview · Post by **Ducklakeview** » Thu Oct 05, 2017 4:07 pm

Smartbear wrote: ↑Thu Oct 05, 2017 4:04 pm
Ducklakeview wrote: ↑Thu Oct 05, 2017 3:51 pm
Scarp wrote: ↑Thu Oct 05, 2017 2:47 pm Here´s the dyno sheet

13327383_969992326448636_6371641669698678403_n.jpg
Looks like hard evidence to me!

Mike
The bhp & torque curves are supposed to intersect at 5250rpm, something is amiss with this graph.
Rob

Why are they supposed to? Looks like they cross @ about 6k, which may tie in with the increased rev limit? Surely every aftermarket map is different?

Mike

Smartbear · Post by **Smartbear** » Thu Oct 05, 2017 4:09 pm

Ducklakeview wrote: ↑Thu Oct 05, 2017 4:07 pm
Smartbear wrote: ↑Thu Oct 05, 2017 4:04 pm
Ducklakeview wrote: ↑Thu Oct 05, 2017 3:51 pm

Looks like hard evidence to me!

Mike
The bhp & torque curves are supposed to intersect at 5250rpm, something is amiss with this graph.
Rob
Why are they supposed to? Looks like they cross @ about 6k, which may tie in with the increased rev limit? Surely every aftermarket map is different?

Mike

It doesn’t matter how much power your car makes, the lines should cross at 5250rpm as the calculation for bhp is torque times revs.
Rob

Ducklakeview · Post by **Ducklakeview** » Thu Oct 05, 2017 4:15 pm

Smartbear wrote: ↑Thu Oct 05, 2017 4:09 pm
Ducklakeview wrote: ↑Thu Oct 05, 2017 4:07 pm
Smartbear wrote: ↑Thu Oct 05, 2017 4:04 pm

The bhp & torque curves are supposed to intersect at 5250rpm, something is amiss with this graph.
Rob
Why are they supposed to? Looks like they cross @ about 6k, which may tie in with the increased rev limit? Surely every aftermarket map is different?

Mike
It doesn’t matter how much power your car makes, the lines should cross at 5250rpm as the calculation for bhp is torque times revs.
Rob

Most wheel dyno programs "scale" the horsepower and torque curves to fit them neatly on the same graph...

And if we are being pedantic, the figure is 5,252

Mike

Steve84N · Post by **Steve84N** » Thu Oct 05, 2017 4:57 pm

I can't read the language but it looks like wheel horsepower is 184 which has then then been translated to 255 at the crank which assumes a ridiculous amount of losses. Assuming 15% losses it would actually be more like 215 which seems about right...

NB: Dynos read wheel horsepower so crank figures are always going to be guestimates. I wish everybody just quoted wheel as it's far more relevant.

GuidoK · Post by **GuidoK** » Thu Oct 05, 2017 5:00 pm

Ducklakeview wrote: ↑Thu Oct 05, 2017 4:15 pm

And if we are being pedantic, the figure is 5,252

Mike

Why should the lines on that dynosheet cross at 5252rpm? (or 5250rpm for that matter)

Ducklakeview · Post by **Ducklakeview** » Thu Oct 05, 2017 5:02 pm

Steve84N wrote: ↑Thu Oct 05, 2017 4:57 pm I can't read the language but it looks like wheel horsepower is 184 which has then then been translated to 255 at the crank which assumes a ridiculous amount of losses. Assuming 15% losses it would actually be more like 215 which seems about right...

NB: Dynos read wheel horsepower so crank figures are always going to be guestimates. I wish everybody just quoted wheel as it's far more relevant.

Dynos actually read torque, not horsepower... The latter is calculated from the torque and rpm figures.

Mike

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