A tale of dynos and mods

[stosh1]

Originally Posted by SYT_Shadow

This morning I was looking at a dyno of a S65 stroker that had a zero hp delta. Negative but that's just the noise.
I do remember the build. I suppose you're Stash1?

Yessir!

[jcolley]

We'll have some data to add to the mix soon. Engine dyno is being set up, hope to have it operational mid-March.

I'm not a fan of inertia dynos at all, nearly useless for comparison and even load type roller dynos can be misrepresented with traction issues. Hub dynos are by far the most accurate and what I prefer to tune on.

The engine dyno will be a means to break in newly built engines and test modifications. It will be nice to be able to keep a motor on it for a week at a time if needed.

[SYT_Shadow]

Originally Posted by jcolley

We'll have some data to add to the mix soon. Engine dyno is being set up, hope to have it operational mid-March.

I'm not a fan of inertia dynos at all, nearly useless for comparison and even load type roller dynos can be misrepresented with traction issues. Hub dynos are by far the most accurate and what I prefer to tune on.

The engine dyno will be a means to break in newly built engines and test modifications. It will be nice to be able to keep a motor on it for a week at a time if needed.

I agree that is the way to go, unfortunately they are not very popular in the US. I remember chatting with the SEAT lead for dyno testing after visiting the factory (they have 20-40 engine dynos) and he laughed at the idea of these dyno tests we like so much over here

[Richbot]

Dynapacks are all over the place! Based on my experience with the one and only one I've been on (with the gone-but-not-forgotten car in my sig actually) need a pretty good water supply to get one to be consistent over long tuning sessions on high-HP engines though, it didn't like a friend's late-model to do more than a few runs at a time, heh

I like the chassis/dynapack for low-hp racecars because driveline or brake drag issues can cause a meaningful amount of loss you might not catch on the engine dyno

[Obioban]

Great to finally see things starting to happen on the S65!

It would be awesome to get
a) dynos over the entire powerband, so if there's any trade offs they're apparent (not for track use, but for street or dual purpose cars)
b) SAE mode on the dynojet. If you have access to the dynojet files, that can be generated retroactively. If you email me all 3 files, I could overlay them at every RPM and switch it over to SAE

Nick's S54 throttle body dyno below. His car is a full bolt (CSL intake, full exhaust, CSL based tune) on S54 plus cams, IIRC. I would say this is about best case for TBs on the s54-- a lower output/more stock S54 would gain less from them then he did. The only difference between the two curves is the Dinan TBs:

Originally Posted by nickpiper12

Here are the results... Blue is Dinan TB's, Red is Stock.



As you can see the losses/gains, however you want to put it, are there, but not drastic. From 6K to redline there's a difference of roughly 3-8 whp and 0-5 wtq.

His dyno is the only one I know of that compares TBs and TBs alone.

He had a dyno tune, from the same tuner, for both setups. Same dyno.

[SVH]

Originally Posted by Obioban

Nick's S54 throttle body dyno below. His car is a full bolt (CSL intake, full exhaust, CSL based tune) on S54 plus cams, IIRC. I would say this is about best case for TBs on the s54-- a lower output/more stock S54 would gain less from them then he did. The only difference between the two curves is the Dinan TBs:

His dyno is the only one I know of that compares TBs and TBs alone.

He had a dyno tune, from the same tuner, for both setups. Same dyno.

That's the first TB comparison I've seen in all the time I've been a member here, or anywhere for that matter. Thanks!
I thought of going that route way back when but was told there's really no difference in power. Seems like an expensive mod for what one would gain.

[SYT_Shadow]

Originally Posted by Obioban

Great to finally see things starting to happen on the S65!

It would be awesome to get
a) dynos over the entire powerband, so if there's any trade offs they're apparent (not for track use, but for street or dual purpose cars)
b) SAE mode on the dynojet. If you have access to the dynojet files, that can be generated retroactively. If you email me all 3 files, I could overlay them at every RPM and switch it over to SAE

Nick's S54 throttle body dyno below. His car is a full bolt (CSL intake, full exhaust, CSL based tune) on S54 plus cams, IIRC. I would say this is about best case for TBs on the s54-- a lower output/more stock S54 would gain less from them then he did. The only difference between the two curves is the Dinan TBs:



His dyno is the only one I know of that compares TBs and TBs alone.

He had a dyno tune, from the same tuner, for both setups. Same dyno.

Slowly but surely things will start happening with the S65 as well!

I don't have dyno files for the E90 full. And the picture I have for it which I used to extrapolate the data doesn't show anything under 5500rpm
I wish I had this because I'm curious if the same thing shows as the Alekshop car: power with cams only overtook the version without cams past like 6k rpm. Not the case on my car but still worth considering.

Someone forwarded a dyno comparison of a stroker S65 with headers and only changing TBs on the same dyno. -2whp. Obviously within the noise, but basically no gain. It's on the dyno database

[Obioban]

Originally Posted by SVH

That's the first TB comparison I've seen in all the time I've been a member here, or anywhere for that matter. Thanks!
I thought of going that route way back when but was told there's really no difference in power. Seems like an expensive mod for what one would gain.

In case you missed it, that's an S54 dyno.

Originally Posted by SYT_Shadow

Slowly but surely things will start happening with the S65 as well!

I don't have dyno files for the E90 full. And the picture I have for it which I used to extrapolate the data doesn't show anything under 5500rpm
I wish I had this because I'm curious if the same thing shows as the Alekshop car: power with cams only overtook the version without cams past like 6k rpm. Not the case on my car but still worth considering.

Someone forwarded a dyno comparison of a stroker S65 with headers and only changing TBs on the same dyno. -2whp. Obviously within the noise, but basically no gain. It's on the dyno database

Below 6k, was power equal with the cams or less than stock?

Hard to believe a cammed/stroker s65 wouldn't benefit from larger TBs, properly tuned. As in, if the stock TBs have no room for improvement with that setup (which should be moving a bunch more air than stock), I wonder if a stock S65 would benefit from smaller TBs than stock!

... but I wonder if that was a tuning issue.

[SVH]

Originally Posted by Obioban

In case you missed it, that's an S54 dyno.

Yeah, I saw that.
Don't really think there's going to be much of a benefit on an s65 either. If that was the case I'd think tuners and producers of SCs would have considered something along those lines.

[SYT_Shadow]

Originally Posted by Obioban

In case you missed it, that's an S54 dyno.



Below 6k, was power equal with the cams or less than stock?

Hard to believe a cammed/stroker s65 wouldn't benefit from larger TBs, properly tuned. As in, if the stock TBs have no room for improvement with that setup (which should be moving a bunch more air than stock), I wonder if a stock S65 would benefit from smaller TBs than stock!

... but I wonder if that was a tuning issue.

Here you go for now

http://www.s65dynos.com/showDyno.php...ype=1&dynoID=1

No cams

[amrazM]

Originally Posted by SYT_Shadow

Here you go for now

http://www.s65dynos.com/showDyno.php...ype=1&dynoID=1

No cams

I’ve heard of this before where dinan tb’s actually lose power.

[jcolley]

Originally Posted by amrazM

I’ve heard of this before where dinan tb’s actually lose power.

Because bigger holes aren't necessarily better for flow. Intake port velocity is what matters the most and a lot of factors go into optimizing it. PipeMax software is useful for calculations like this. In the LS world depending on application, some head gurus are epoxy filling intake ports and regrinding them with smaller diameters for this very reason.

[Obioban]

Originally Posted by SYT_Shadow

Here you go for now

http://www.s65dynos.com/showDyno.php...ype=1&dynoID=1

No cams

Yeah-- that's why I was saying that maybe smaller (than stock) TBs would increase power on an otherwise stock engine.