[Trofeo]

I strapped the M235 to a chassis dyno known as the ultimate heart breaker.
383whp 430wtq.
My Bootmod3 data-log was cutting in and out and only have about 13 seconds of data.
Boost is 18.7.
My AFR is in the 12.1 range.
Big kudos to Jordan for the custom tuning for 93 octane. In addition to the obligatory upgrades are Dorch HPFP, Snow Meth injection, 1 step colder NGK plugs.

[Dynamic_m235]

Originally Posted by Trofeo

I strapped the M235 to a chassis dyno known as the ultimate heart breaker.
383whp 430wtq.
My Bootmod3 data-log was cutting in and out and only have about 13 seconds of data.
Boost is 18.7.
My AFR is in the 12.1 range.
Big kudos to Jordan for the custom tuning for 93 octane. In addition to the obligatory upgrades are Dorch HPFP, Snow Meth injection, 1 step colder NGK plugs.

Are you AWD?

[Trofeo]

Yes. I forgot to mention it's an AWD. This is a Mustang Dyno which explains the numbers.

[Dynamic_m235]

Originally Posted by Trofeo

Yes. I forgot to mention it's an AWD. This is a Mustang Dyno which explains the numbers.

Yea I figured that's why they read low

[AmuroRay]

What's happening post 600RPM?

[KennyFSU]

Originally Posted by AmuroRay

What's happening post 600RPM?

Stock snail running out of steam.

[AmuroRay]

Originally Posted by KennyFSU

Stock snail running out of steam.

Not even close - you can make 350+WHP at 7000RPM.

[mike@x-ph.com]

Originally Posted by KennyFSU

Stock snail running out of steam.

It looks like the dyno operator let go of the gas paddle after 5000rpm

[AmuroRay]

Originally Posted by mike@x-ph.com

It looks like the dyno operator let go of the gas paddle after 5000rpm

That's what it looks like to me. A EWG should be making peak power after the HP/TQ crossover - around 5700-6000RPM.

[mike@x-ph.com]

Originally Posted by AmuroRay

That's what it looks like to me. A EWG should be making peak power after the HP/TQ crossover - around 5700-6000RPM.

I understand when tuners don't push the car to its max on high RPM, it's just a lot safer but the dyno posted has a sudden decrease.
You are correct, to looks off

[Trofeo]

Again....This tuner uses a Mustang dyno. A pro shop used to tune drag cars. It's not a Dynojet! Hence the lower numbers.
Let's use the Dynojet's translation, which became a rule of thumb on automotive forums for manual transmission cars. The percentage changes based on if the car is automatic (20%) or even all wheel drive and automatic (25%). Here we have the total following the Dynojet logic:

WHP
Mustang: 383.5 @20% Dynojet: 460.1
Mustang: 383.5 @25% Dynojet: 479.4

A good read: https://www.igotasti.com/threads/mus...am-maker.5230/

[Trofeo]

Originally Posted by AmuroRay

Not even close - you can make 350+WHP at 7000RPM.

Huh???

[AmuroRay]

Originally Posted by Trofeo

Again....This tuner uses a Mustang dyno. A pro shop used to tune drag cars. It's not a Dynojet! Hence the lower numbers.
Let's use the Dynojet's translation, which became a rule of thumb on automotive forums for manual transmission cars. The percentage changes based on if the car is automatic (20%) or even all wheel drive and automatic (25%). Here we have the total following the Dynojet logic:

WHP
Mustang: 383.5 @20% Dynojet: 460.1
Mustang: 383.5 @25% Dynojet: 479.4

A good read: https://www.igotasti.com/threads/mus...am-maker.5230/

I know how dynos work, I’ve been on more than my fair share. I’m not talking about peak number, I’m specifically speaking of why the cars power drops off so significantly after 5000RPM.

[mike@x-ph.com]

Originally Posted by Trofeo

Again....This tuner uses a Mustang dyno. A pro shop used to tune drag cars. It's not a Dynojet! Hence the lower numbers.
Let's use the Dynojet's translation, which became a rule of thumb on automotive forums for manual transmission cars. The percentage changes based on if the car is automatic (20%) or even all wheel drive and automatic (25%). Here we have the total following the Dynojet logic:

WHP
Mustang: 383.5 @20% Dynojet: 460.1
Mustang: 383.5 @25% Dynojet: 479.4

A good read: https://www.igotasti.com/threads/mus...am-maker.5230/

Forget the numbers, that's not my concern. Its the drop.

Did you show the dyno to Cary? If so please let us know what he says about the sudden drop.

He's the expert, if the drop is intentional, he will have a good reason for it.

[XutvJet]

Given that this a Mustang Dyno and the car is running meth with a custom tune, this N54-like powerband doesn't surprise me one bit.

It's very common for EWGs N55 on meth to make huge power to around 5000-5200rpms and then die out quickly, comparitively speaking to the massive power gain from 3500-5200rpms. Mustang Dynos make this effect way more pronounced, especially if the dyno operator is applying a good amount of brake to increase load. This N55 is seeing around 260whp at 6000-6200rpms on the Mustang Dyno. That would be around 320whp on the Dynojet. About what I'd expect from this mod combo.

The gear dynoed in can also be a factor.

Personally, I'm not a fan of these diesel-like powerbands, but the car will still be quite fast.

I certainly do not agree that AWD sucks out 25% power to the wheels. It's more like 15%. The RWD 6MTs see about a 10% loss.

On a Dynojet this car will make ~420whp and 460wtq. Definitely good for low 11s in XDrive.

[AmuroRay]

Even if the Mustang dyno has a 8% reduction (about standard) vs a Dynojets, those numbers still don’t make sense. The car loses 100whp in 1000RPM, which is ridiculous regardless of whatever dyno platform you use.
On a EWG with meth, you’re also not making peak power at 5000rpm, unless the tuner is tying to tune it like a PWG turbo

[XutvJet]

Originally Posted by AmuroRay

Even if the Mustang dyno has a 8% reduction (about standard) vs a Dynojets, those numbers still don’t make sense. The car loses 100whp in 1000RPM, which is ridiculous regardless of whatever dyno platform you use.
On a EWG with meth, you’re also not making peak power at 5000rpm, unless the tuner is tying to tune it like a PWG turbo

This is the nature of using meth and it's delivery. It is not a smooth transition as the delivery system is rather rudimentary. As a result, you get a nitrous-like power curve.

[Lex@JordanTuned]

Hey guys, on behalf of JordanTuned, after reviewing logs from this dyno run it becomes apparent the car had a boost leak during this run. Seems he was making great power until that leak caught up to him in higher RPMS.

[AmuroRay]

Originally Posted by XutvJet

This is the nature of using meth and it's delivery. It is not a smooth transition as the delivery system is rather rudimentary. As a result, you get a nitrous-like power curve.

No. Read the post above mine.

[XutvJet]

I still don't buy it. The OP said his data log was short and the data cutting in and out. How can they determine a boost leak was occurring with weak data?

Also, power was very strong right up until 5200rpms, well after peak boost was made. There appears to be no issues with power from 2000-5200rpms and max boost was likely occuring at 2500-5000rpms and then tapering. If you're going to have a leak, one would think you'd see it when max boost was happening.

If anything, the AFR could be going a bit rich in the upper rpms hence the power drop after 5200rpms. It could be a tuning issue or perhaps the DME was seeing knock and dumping fuel and closing the throttle.

Like I noted earlier, other EWG N55s have shown similar power bands with meth where power ramps up to ~5200rpms and then plummets, some worse than others. For reasons I can't totally explain, meth changes the shape of the power band and pushes peak power to the lower 5000s vs lower 6000s like we typically see on EWG N55s. Perhaps a turbo efficiency thing.

PWG N55s on meth tend to see peak power in the 4800rpm range and then drop. Yuck.

[AmuroRay]

Originally Posted by XutvJet

I still don't buy it. The OP said his data log was short and the data cutting in and out. How can they determine a boost leak was occurring with weak data?

Datalog could still show a boost leak, it could still show him missing targets.

Originally Posted by XutvJet

Also, power was very strong right up until 5200rpms, well after peak boost was made.

How do you know? There is no data log that shows what his boost is.
Here is MY datalog and notice I make peak boost closer to 6000RPM

https://datazap.me/u/amuroray/log-16...ta=3-4-5-15-24

Originally Posted by XutvJet

There appears to be no issues with power from 2000-5200rpms and max boost was likely occuring at 2500-5000rpms and then tapering. If you're going to have a leak, one would think you'd see it when max boost was happening.

Not necessarily. Without a log you can't say - he's making power, but it doesn't look like he's making anything special. In fact, those numbers look like Dynoject converted numbers (Which Mustang Dynos can do) which would mean they aren't that special considering the other cars out there.

Originally Posted by XutvJet

If anything, the AFR could be going a bit rich in the upper rpms hence the power drop after 5200rpms. It could be a tuning issue or perhaps the DME was seeing knock and dumping fuel and closing the throttle.

So we agree losing 100WHP in 1000 RPM is NOT normal, right? We also agree that making less than 300WHP at fuel cut is not normal, right?

Originally Posted by XutvJet

Like I noted earlier, other EWG N55s have shown similar power bands with meth where power ramps up to ~5200rpms and then plummets, some worse than others. For reasons I can't totally explain, meth changes the shape of the power band and pushes peak power to the lower 5000s vs lower 6000s like we typically see on EWG N55s. Perhaps a turbo efficiency thing.

PWG N55s on meth tend to see peak power in the 4800rpm range and then drop. Yuck.

I've never seen this on a EWG, and I've inspected dynos heavily:



https://f30.bimmerpost.com/forums/sh...1622618&page=2


Same car:

[XutvJet]

- I do not believe "BMW DIY Guy" had meth on his F30 N55. I thought he did the HPFP only.

- Mustang dyno numbers are wildly variable because the operator can apply brake to increase load. That's why they're so freaking great for tuning. You can essentially tune the car for street driving like grades and such. A Dynojet is a very simple dyno, more for measuring power than tuning. A Dynojet can't vary load. The measurement is simply how quickly the motor can spin a 2,000lb drum over a given amount of rpm and time. It's crazy simple and generally repeatable.

- I do not see anything on the dyno plot suggesting the Mustang dyno numbers are being converted to reflect Dynojet numbers. I've been modding cars since 1995, spent countless hours on various automotive forums since the dial-up age, have dynoed many of my cars, and I can't recall any shops converting Mustang dyno numbers to Dynojet numbers. Again, it's totally an apples to oranges comparison. However, Mustang dynos definitely show much lower whp/wtq numbers than a Dynojet and it often confuses the crap out of most people that don't understand the differences in how the power is measured.

- It would help if we knew which gear the OP dynoed in as it greatly influences turbo load and ultimate numbers.

- You'd be surprised at the difference in the power curve if this car was dynoed on a Dynojet. It's also VERY common for Mustang dynos to show a 200-300rpm earlier peak in the power curve vs the Dynojet. Why? I have not clue but I've seen the phenomenon on a number of cars over the years that dynoed on Mustangs dyno and then Dynojets or vice versa and no changes in mods/tuning. I have not a clue why it happens. It's above my pay grade.

- I'm not saying definitively that there might not be an issue here, but I'm not seeing evidence of a boost leak. If anything is happening, my guess is meth delivery and DME reaction, especially after 5200rpms.

- Like I've said earlier, this huge surge in power followed by a quick drop in power is common to meth injected BMW turbo motors and most any meth injected car for that matter. With the HPFP upgrades now, I don't know why you'd want to use meth.