Bootmod3 S55 TQ limitation OTS tests - on STOCK and UPGRADE turbos - dynorun results

[Simmadown115]

Originally Posted by blockdoc

How is that if you cut boost by 20 percent across the board! Sorry for being dense here

I was in the same mindset of you until I kept following Halim's updates and descriptions. The boost by gear setting is not a boost reduction factor, but a torque then load then boost reduction factor.

If you set the limit to 25% so that the stock motor would only have ~300ftlbs of Torque, anytime the motor is producing less it will operate normally. When starts to produce more than 300 it will cut the boost to limit it to that factor. That's where the reduction by gear comes into play.

When you upgrade turbos and can generate 600 ftlbs of torque, if you set a limit to it, you will limit the torque to a higher number. It can generate a flat response by having it cut a percentage of the overall torque limit and when the stock turbos would start to fall on their face and produce less than the limit, upgraded turbos still boost and give you that top end to make a difference.

Boost by gear helps you keep traction in lower rpms for tracking and spirited driving. If you're the 60-130 queen, you should already know that you never see the lower RPMS from the gearing and spend most of your time in the upper RPMS.

[SYT_Shadow]

In the M4 with stock turbos and downpipes, the 20% reduction map looks quite beautiful

I wonder what it looks like vs a stock M4 GTS map. Very curious!

[ICantDrive4Sht]

Originally Posted by blockdoc

How is that if you cut boost by 20 percent across the board! Sorry for being dense here

You don`t limit it accross the board. Or you can, but why would you?
It`s boost by gear, which means you can for example limit 1st and 2nd gears only, if you want.

[blockdoc]

Originally Posted by ICantDrive4Sht

You don`t limit it accross the board. Or you can, but why would you?
It`s boost by gear, which means you can for example limit 1st and 2nd gears only, if you want.

According to the post, it was a 20 percent reduction across the board. Hence, my confusion.

But i do appreciate the explanations. It sounds like this map does neuter the upgraded turbos...at least until the higher rev limits which is where they differ from the puny stock turbos (in which efficiency drops off dramatically long before redline)

[M3SQRD]

Originally Posted by blockdoc

According to the post, it was a 20 percent reduction across the board. Hence, my confusion.

But i do appreciate the explanations. It sounds like this map does neuter the upgraded turbos...at least until the higher rev limits which is where they differ from the puny stock turbos (in which efficiency drops off dramatically long before redline)

Torque (boost) limiting is done by gear. For example, you could limit torque on 1st and 2nd gears only, and no limiting on remaining gears. This means you’d have full torque (boost) on gears three and up.

[blockdoc]

Originally Posted by M3SQRD

Torque (boost) limiting is done by gear. For example, you could limit torque on 1st and 2nd gears only, and no limiting on remaining gears. This means you'd have full torque (boost) on gears three and up.

I get it and agree. But once again, the OP modeled a 20 percent reduction across all gears.

[Simmadown115]

Originally Posted by blockdoc

I get it and agree. But once again, the OP modeled a 20 percent reduction across all gears.

He has to in order to run the Dyno in 4th, 5th, and 6th to get it near the 1:1 drive ratio to measure the torque correctly. Any gear below that isn't near 1:1 so you can't measure it right on the dyno.

[ssgm1x]

Going off the Dyno Plots it looks like boost by gear is mostly limiting Torque and not effecting Horespower much at all. I like this a lot !!!!

[chewbakam4]

Originally Posted by ssgm1x

Going off the Dyno Plots it looks like boost by gear is mostly limiting Torque and not effecting Horespower much at all.

HP and torque are actually directly related. Hp is calculated based on torque and RPM, I forget the equation.

[Halim@HCP]

Originally Posted by blockdoc

According to the post, it was a 20 percent reduction across the board. Hence, my confusion.

But i do appreciate the explanations. It sounds like this map does neuter the upgraded turbos...at least until the higher rev limits which is where they differ from the puny stock turbos (in which efficiency drops off dramatically long before redline)

Well if we reduce peak HP with 20% as well the you might as well want to run the stock map

The whole post is about to bring down torque and still maintain that HP, so the car feels like NA. Moreover it's also to show that you can lower torque to get grip, especially in lower gears, i.e. 1st 2nd and 3rd gear.

[blockdoc]

Originally Posted by Halim@HCP

Well if we reduce peak HP with 20% as well the you might as well want to run the stock map

The whole post is about to bring down torque and still maintain that HP, so the car feels like NA. Moreover it's also to show that you can lower torque to get grip, especially in lower gears, i.e. 1st 2nd and 3rd gear.

Lol. I probably made this WAY more
Confusing than it needed to be. I run a PJT Custom tune anyways, so doesn't really affect me. Was just curious.

Thanks for your patience

[Halim@HCP]

Originally Posted by blockdoc

Lol. I probably made this WAY more
Confusing than it needed to be. I run a PJT Custom tune anyways, so doesn't really affect me. Was just curious.

Thanks for your patience

[overlook637]

Originally Posted by ICantDrive4Sht

You don`t limit it accross the board. Or you can, but why would you?
It`s boost by gear, which means you can for example limit 1st and 2nd gears only, if you want.

One reason to limit torque is to save clutches or prevent the need to upgrade clutches.

Adjust for boost limit to keep torque levels at safe limits. Then with bigger turbos you can pull that safe torque all the way up to redline. Boost by gear is a great way for self tuning. Alternative would be to pay $$$$ for a dyno time and a custom flat torque tune.

The goal is traction and save clutches. I don't really care much about making the car feel like its NA. I paid money for twin turbos and ok with turbo dyno's. However we must work with the limits of the clutches and traction of tires.

[Halim@HCP]

Originally Posted by Simmadown115

He has to in order to run the Dyno in 4th, 5th, and 6th to get it near the 1:1 drive ratio to measure the torque correctly. Any gear below that isn't near 1:1 so you can't measure it right on the dyno.

All runs are done in 5th gear as it is 1:1 on the DCT.

[Halim@HCP]

Originally Posted by overlook637

One reason to limit torque is to save clutches or prevent the need to upgrade clutches.

Adjust for boost limit to keep torque levels at safe limits. Then with bigger turbos you can pull that safe torque all the way up to redline. Boost by gear is a great way for self tuning. Alternative would be to pay $$$$ for a dyno time and a custom flat torque tune.

The goal is traction and save clutches. I don't really care much about making the car feel like its NA. I paid money for twin turbos and ok with turbo dyno's. However we must work with the limits of the clutches and traction of tires.

I run around 680wtq on my m3 daily, for last 8000km no issues with clutches! As long as the load/torque is properly reported there are no longevity issues. These clutches are the same as used in the M5 M6!

Limitation of the TQ is mostly for traction/trackdays

[SYT_Shadow]

Halim@HCP is there any way you can overlay the 20% reduction map with a M4 GTS stock map? I'd be very interested in seeing that

[FTP20]

Originally Posted by Halim@HCP

The whole post is about to bring down torque and still maintain that HP, so the car feels like NA.

This is exactly what I want from a tune! Give me a little bit more torque than the stock map but no big torque spike in the midrange and as much HP past 5252rpm as possible.

Halim@HCP which BM3 91oct map do you think best fits my description ?

[Padfan9]

@Halim@HCP any chance we could see stage 1 BM3 on a stock comp package F80/82? I would love to see those results.

[Reid]

Originally Posted by Padfan9

@Halim@HCP any chance we could see stage 1 BM3 on a stock comp package F80/82? I would love to see those results.

click

[Vegetable]

Hi Halim@HCP I love all the torque in the higher gears (3rd-6th) and it still feels just as linear as stock, only in an obviously more robust amount. But like everyone with the OTS stage 1/2 91/93 octane tune, traction is a bitch at times with anything more than a 50% throttle run from a standing start . Currently I am running a 40% boost reduction in 1st and a 20% boost reduction in 2nd and no boost reduction in 3rd+. Do you see any advantage in your formula of a 20% reduction across the board who are only having issues in 1st and 2nd? I'm a total novice with this tune, so thank you.

[Rick448]

If I change my purchased Stage 1 map and rename it, can I still get the original Stage 1 map from the OTS maps and add it to my maps?

[SeanWRT]

Is my understanding correct that the boost limit isn't a constant % of boost reduction applied across the rev range, instead it works like a boost cap, as a result, the top end is less affected because boost tapers there anyway.

It looks to me 100% true that tuner/user adjustment via boost cap is much easier given way S55 OTS map is calibrated. And I think things can be very different with S63/N55/N20. Could even see the opposite.