Gotta take pics of the spare N54 head I have in my garage and list it for whoever wants to pursue the same as you Filippo.
N54 head work
- Thread starter fmorelli
- Start date
Ok, knocked out 850 miles today into the heart of Wisconsin. Tomorrow, reverse but with a quick stop in to spend a couple hours with @NoQuarter.
Filippo
Filippo
Very interesting post,
Why did you choose to run low lift cams without upgraded springs ?
I'm currently getting a full setup from Hydra and i hesitated in going cams, then i hesitated in going springs.
My concern was how would the stock valvetrain cope with the higher lift, and higher rpm, with the cams.
I ended up going both cams and springs...
Why did you choose to run low lift cams without upgraded springs ?
I'm currently getting a full setup from Hydra and i hesitated in going cams, then i hesitated in going springs.
My concern was how would the stock valvetrain cope with the higher lift, and higher rpm, with the cams.
I ended up going both cams and springs...
Low lift cams and stock N53 valvetrain seem to be a good match.
High lift I'd overhaul it though.
If you are touching the head why would you not to upgrade the springs? Or a better question, why keep the stock rev limit?
I believe it was already stated in this thread, but high lift cams only have 0.5mm more lift than low lift cams. I believe low lifts are 11.5/10.5mm In/Ex and high lifts are 12/11mm In/ex.
This is a huge increase over stock even for the low lifts, how would the stock valve train cope with that @ 7500rpm ?
@Hydra Performance is the better one to answer that question.
Mine is currently running out to 75/7600 with the N53 head and other than a failing LPFP, no obvious problems.
Budget & overall reliability
Also, in Filippo's specific case, the HP650s run out of airflow sooner so a 7200rpm redline with cams is no hindrance.
I've said it before, the performance delta between low-lift and high-lift cams on an N54 head - even ported - is minimal. Ports are simply too small w.r.t to valve diameters to make high L/D ratios efficient.
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Valve lift is only 1 ingredient in the HP recipe. Duration and ramps play a larger role IMO.
IIRC ignition hard limit is 8,250. So at 7,200 there is a lot of power left on the table.
I'd be interested in knowing the weights of the aftermarket valvetrain vs stock. I have a sneaking suspicion that aftermarket is heavier, which isn't going to help with raising the RPM ceiling.
IIRC ignition hard limit is 8,250. So at 7,200 there is a lot of power left on the table.
I'd be interested in knowing the weights of the aftermarket valvetrain vs stock. I have a sneaking suspicion that aftermarket is heavier, which isn't going to help with raising the RPM ceiling.
Thank you for that information.
I would kill for another 1k rpms on my single. I continually go back and forth on building the n54 head I have laying around...Just hard to drop 4k on a fully worked head + 1.5k on cams + $400 for arp fasteners + $250 for a head gasket. 6k without install basically. Costs as much as my ACF single turbo. If I do all of that I might as well get a proper FF intake manifold for 2k to take advantage of the worked head etc. This is where I stop every time. Invest 8kish? Bottom end is still not built.
If my prices are wrong, please correct me.
It is still strange you rarely see an N54 reving beyond the stock DME limit of ~7200. Even the guys going for 1k whp etc. Maybe there is something I don't know?
Another thing that is strange is I still don't know who I would trust for a built head or motor 14 years after the n54 was released.
I've installed the low lift cams and have the data exactly how much difference they make on a back to back setup.
I can tell you with that the low lifts make a little bit more power with 4 psi less boost but loads more torque everywhere.
I don't want to release it just yet till we finalise the tune but been waiting on my new gearbox as 3rd gear disintegrated during a 3rd gear pull.
Stock springs are fine with low lifts and are not needed, by far best bang for buck mod that really wakes the car up.
It's like having a playful puppy grow into a feral dog.
The response, the virtually instant spool and the bread loaf like torque curve is just stupid good.
Just to show you the log where the 3rd gear broke at around 4k rpm
I can tell you with that the low lifts make a little bit more power with 4 psi less boost but loads more torque everywhere.
I don't want to release it just yet till we finalise the tune but been waiting on my new gearbox as 3rd gear disintegrated during a 3rd gear pull.
Stock springs are fine with low lifts and are not needed, by far best bang for buck mod that really wakes the car up.
It's like having a playful puppy grow into a feral dog.
The response, the virtually instant spool and the bread loaf like torque curve is just stupid good.
Just to show you the log where the 3rd gear broke at around 4k rpm
Keep stock rev limit - in the worlds of The Old One, "RPM stands for ruins peoples motors."
I've installed the low lift cams and have the data exactly how much difference they make on a back to back setup.
I can tell you with that the low lifts make a little bit more power with 4 psi less boost but loads more torque everywhere.
I don't want to release it just yet till we finalise the tune but been waiting on my new gearbox as 3rd gear disintegrated during a 3rd gear pull.
Stock springs are fine with low lifts and are not needed, by far best bang for buck mod that really wakes the car up.
It's like having a playful puppy grow into a feral dog.
The response, the virtually instant spool and the bread loaf like torque curve is just stupid good.
Just to show you the log where the 3rd gear broke at around 4k rpm
Whose low lift cams do you have?
do you know what is the duration and ramp rate like on the low-lift cams compared to stock?
the n54 valve seats are so small its hard to see lift on its own contributing much to airflow. without getting calipers out and a spare head it seems the to me the stock lift is already getting close to diminishing returns w.r.t to the lift ratio.
if i were designing an all out n54 cam i'd investigate being as aggressive as practical on the ramp angles and that would lead to needing higher spring rates on a lower lift cam. can only take lift so far like you say because its effectiveness is married to port/valve seat sizing.
No I do not, and tbh its not that important. I do know that the Schrick low-lift cams are useful on an N54 head - whether stock or ported, and that AVL Schrick are an OEM-grade and premier league motorsports supplier so I would gladly trust their judgement. There is nothing "all out" about the N54 head design which warrants any kind of all out effort IMHO. I don't want to sound like a broken record, but the N53 head conversion really is the single biggest gamechanger on this platform, turns an ugly duckling into a swan. I've experienced this first hand on several occasions, as have several members on here, and I'm sure they will agree with my claims whole-heartedly. Think of it as an 2v/cyl vs a 4v/cyl version of the same engine. Sure you can spend time, effort, and money improving the former, but it'll never be as capable overall as the latter.
PS - duration on the Schrick low lifts is 268/268 seat vs a claimed 248/261 for the stockers, but it is duration @ 1mm we are more interested in and I have no hard data for you, but should be in the region of ~228deg give or take
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You're looking at $2,000 for a Ferrea valvetrain for the N54, give or take. Say $1,500 or so for cams. Head ports ... YMMV on who is doing them, but it's a $2k activity for US guys, if one is doing CNC, I believe. Finding old school porting guys ... not as easy as it was 20 years ago.
I back in Virginia after a 1,700 mile slog. The 535d crushed the trip but I'm nonetheless a bit tired.
I just want to say, because I post these things I hardly recommend the approach lol. I do think the N54 head is woefully ill designed for putting out 1.5-3x the power it was designed to deal with, emissions priorities, etc. My approach has its reasons, which are likely not relevant to the thread.
I don't say this experientially, but objectively based on what I know. When I ordered the HP650s from @Hydra Performance, I had not gotten to the point of researching the head and making decisions on that. My intention was to leave it alone - it was a significant expense, as @Torgus pointed out, and I was not going after big big horsepower like some of the guys here. By the time the HP650s arrived, I had convinced myself that the head was a major bottleneck which was likely introducing a fair bit of heat, in part also due to boost PSI necessary to deal with the head's inefficiency for greater power production. I felt compelled to address the head in hopes of maybe dropping 3-5psi in pursuit of my target. I like to say, "heat is the devil", and I'm after and overall build that is highly reliable and performant.
That said, had I figured out what I had before I ordered the HP650s, I would have spent the money on the N53 head/manifold/turbo package from @Hydra Performance. I believe that is the way to go. The change in exhaust manifold really seems to make it an all or nothing decision. The pricing I had from Omar was reasonable when we discussed it.
But as of now, I'm invested in the current setup and will see through the ported head, Schrick cams (thanks Sean @Panzerfaust!), with HP650s. I'm sure the head will be a great improvement over stock, and maybe one more set of data points to share out when finished. My next step is to assess the port work that was done - I have a engine hot shoe friend that is back in town from Texas, Troy McBain who has opened UM Performance. He's going to give it a once over. I have some clean up work I will personally do (e.g. intake dividers need more knife edge, polish work on the intake runners and back of intake valves). I expect to get it flowed just so we know where it is at. Machine shop will take care of a few things, and @barry@3DM will build the head once we are done with the 3DM TTX Öhlins suspension development.
Filippo
I back in Virginia after a 1,700 mile slog. The 535d crushed the trip but I'm nonetheless a bit tired.
I just want to say, because I post these things I hardly recommend the approach lol. I do think the N54 head is woefully ill designed for putting out 1.5-3x the power it was designed to deal with, emissions priorities, etc. My approach has its reasons, which are likely not relevant to the thread.
I don't say this experientially, but objectively based on what I know. When I ordered the HP650s from @Hydra Performance, I had not gotten to the point of researching the head and making decisions on that. My intention was to leave it alone - it was a significant expense, as @Torgus pointed out, and I was not going after big big horsepower like some of the guys here. By the time the HP650s arrived, I had convinced myself that the head was a major bottleneck which was likely introducing a fair bit of heat, in part also due to boost PSI necessary to deal with the head's inefficiency for greater power production. I felt compelled to address the head in hopes of maybe dropping 3-5psi in pursuit of my target. I like to say, "heat is the devil", and I'm after and overall build that is highly reliable and performant.
That said, had I figured out what I had before I ordered the HP650s, I would have spent the money on the N53 head/manifold/turbo package from @Hydra Performance. I believe that is the way to go. The change in exhaust manifold really seems to make it an all or nothing decision. The pricing I had from Omar was reasonable when we discussed it.
But as of now, I'm invested in the current setup and will see through the ported head, Schrick cams (thanks Sean @Panzerfaust!), with HP650s. I'm sure the head will be a great improvement over stock, and maybe one more set of data points to share out when finished. My next step is to assess the port work that was done - I have a engine hot shoe friend that is back in town from Texas, Troy McBain who has opened UM Performance. He's going to give it a once over. I have some clean up work I will personally do (e.g. intake dividers need more knife edge, polish work on the intake runners and back of intake valves). I expect to get it flowed just so we know where it is at. Machine shop will take care of a few things, and @barry@3DM will build the head once we are done with the 3DM TTX Öhlins suspension development.
Filippo
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Here's where we'll be picking up from ...
Filippo
Filippo
