S50/S52 swap... is it worth it?

[bimmerteck]

Pull 1 - stock
Pull 2 - underdrive pulleys
Pull 3 - pulleys and fan removed

Total gain from pull 1 to pull 3 was like 6.6hp iirc on a 90 degree Birmingham day with that wonderful "swamp like" southern humidity and the motor at operating temp for all pulls. Difference from pulls 1-2 (pulleys alone) would be labeled *statistically indifferent if I were presenting the data. ;)

[dinanm3atl]

Yah. How much power? 6 or 7 combined with under drive pullies?

[bimmerteck]

What? I thought FDM got you like 10-15hp? I read it on bf.c! Totally worth it!

I didn't do the famed "FDM" (thermostat/water wetter/fan removal ect) I simply removed the factory fan in between runs to see the effect. no other changes.

[dinanm3atl]

What? I thought FDM got you like 10-15hp? I read it on bf.c! Totally worth it!

[bimmerteck]

I've never dyno'd back to back. I would guess pullies are closer to 2hp than 10hp. much closer to 2hp.

I would do pullies for the better high RPM cooling and extended accessory life at high RPM, not for the power.

We dynoed an s50 powered e36 m3 with the addition of under-drive pulleys, then with under-drive pulleys and no mechanical fan, it gained more from removing the mechanical fan but it was only 6 or 7hp total, but I still recommend installing them for one reason.

1. They completely eliminate the risk of a failing plastic BMW pulley.

[nando]

Doesn't matter what dyno. Stock S52s dyno on a dynojet between 205-210whp. The gains from there to modded are quite real, so I don't get the dynojet hate.

that's exactly what my point was. it shows the gains from individual mods and tuning. you can't use it to calculate an exact crank #. and dynojets are *widely* known to show higher numbers than other dynos. that does matter when you're trying to guess at what crank HP it makes. All you've shown is it's easy to hit 245whp.. on a dynojet. that's nice.

220hp*1.15 is a big step from 240hp*1.15

[fsmtnbiker]

I've never dyno'd back to back. I would guess pullies are closer to 2hp than 10hp. much closer to 2hp.

I would do pullies for the better high RPM cooling and extended accessory life at high RPM, not for the power.

[Adrian_Visser]

On the subject of bolt ons does anyone have a dyno chart showing a direct comparison between under drive pulleys vs. regular pulleys on the same dyno?

I have Eurosport under drive pulleys on my engine and even looking at the charts they advertise on their site they are only claiming a 2whp gain on an s52 where as on an m52 they advertise 8 or 10whp (can't remember exactly) Why is that anyway?

[bimmerteck]

Wow, no kidding. Good info!

I can also add to this thread that the euro s50b32 is cheaper than an s54 only in the electronics/throttle control portion of the swap, it could actually likely end up just as expensive due to the donor motor being several years older than the s54 donor was, and the cost incurred shipping it to the states. Not to mention some additional time spent during the build waiting on parts from Europe.


I'm still trying to talk someone into a newer n54 swap so I can go full bore with the servotronic steering, traction control, and a 6 speed. . .

[giantkeeper]

That's where the s54 swap sneaks up and bites you in the ass, EVERYTHING we ordered for that swap was more expensive often 20%-40% occasionally it was as much as 10x!

for example I wanted to refresh the cooling system and do some other common maintenance while the s54 was on the stand. . .

s52 water pump- $52
s54 water pump- $406 $354!

Spark Plugs
s52 -$10 x6
s54 -$15 x6 $30!

UUC Flywheel/clutch
e36 5 speed-$895
e46 6 speed-$1,195 $300

Motor Oil
s52 -$7 x7
s54 -$13 x6 $29

That's $713 more just for 4 typical maintenance things I do on almost all my swaps!

and yet I still miss my S54

[Bimmerman325i]

That's where the s54 swap sneaks up and bites you in the ass, EVERYTHING we ordered for that swap was more expensive often 20%-40% occasionally it was as much as 10x!

for example I wanted to refresh the cooling system and do some other common maintenance while the s54 was on the stand. . .

s52 water pump- $52
s54 water pump- $406 $354!

Spark Plugs
s52 -$10 x6
s54 -$15 x6 $30!

UUC Flywheel/clutch
e36 5 speed-$895
e46 6 speed-$1,195 $300

Motor Oil
s52 -$7 x7
s54 -$13 x6 $29

That's $713 more just for 4 typical maintenance things I do on almost all my swaps!

Wow, no kidding. Good info!

[bimmerteck]

Right, I didn't include in the $6k the cooling/exhaust/misc costs, but they aren't all that different from an S50/2 swap, so I'm just using that as a constant cost for both swaps.

I mentioned that I didn't include any of that. The $6k is the cost for motor and electronics/DBW kit. That DIRECTLY compares to the $2-3k cost for an S50/2 + electronics without mods. All other costs are not much different, and are assumed to be constant.

That's where the s54 swap sneaks up and bites you in the ass, EVERYTHING we ordered for that swap was more expensive often 20%-40% occasionally it was as much as 10x!

for example I wanted to refresh the cooling system and do some other common maintenance while the s54 was on the stand. . .

s52 water pump- $52
s54 water pump- $406 $354!

Spark Plugs
s52 -$10 x6
s54 -$15 x6 $30!

UUC Flywheel/clutch
e36 5 speed-$895
e46 6 speed-$1,195 $300

Motor Oil
s52 -$7 x7
s54 -$13 x6 $29

That's $713 more just for 4 typical maintenance things I do on almost all my swaps!

[Bimmerman325i]

all dynojet graphs. It's great that they gained so much over stock, but they'd probably be 15-20whp less on a different dyno. It illustrates that chasis dynos are for tuning, not for bragging.

Doesn't matter what dyno. Stock S52s dyno on a dynojet between 205-210whp. The gains from there to modded are quite real, so I don't get the dynojet hate.

The numbers aren't firm hard numbers, but what they do show is the gains from mods at the rear wheels, and thus the gains at the motor are 15-18% higher when drivetrain loss is accounted for.

The numbers would be 15-20whp less on a different dyno, but so would the stock graphs and numbers!!!! So again, I don't see where your dynojet hate is coming from. The point is to show gains vs stock, which these do extremely well.

[Bimmerman325i]

Post #2: Non-cammed S52s.


99 M3
Mods: 3.5"Ecis Cai, Euro HFM, M50 Manifold, Stromung Exhaust, AA Custom Software


99 M3
Mods: M50 Intake Manifold, Conforti 3.5" CAI, AA Software, 3.5" HFM (unplugged), Fan Delete, Strömung Exhaust, UUC Stg2 Ltw Flywheel w/ Stg1 Clutch, AA Track Pipe


95 M3 with 3L S50, Pre/Post Schrick install
Mods:Eurosport/Conforti/Schrick package, shorty SuperSprint headers, stock cats, Stromung exhaust, underdrive pulleys, fan delete, 91 octane


Something odd going on at 6krpm, power likely would go higher
98 M3 92k
Mods: AA 3.5 CAI, 540 HFM, BW elbow, M50, 24# injectors, underdrive pulleys, UUC ltw fly, Raceland headers, custom 3' exhaust (just a Borla muffler), Conforti software.

I could go on, but I have to finish some stuff for class.

[nando]

all dynojet graphs. It's great that they gained so much over stock, but they'd probably be 15-20whp less on a different dyno. It illustrates that chasis dynos are for tuning, not for bragging.