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Discussion Starter · #1 · (Edited)
I made a few sets of my short stacks back in December that didn't seem to gain much interest outside of the FB group. So I had a chance this weekend to put them on a dyno for some testing. Below is the story and results.

"We got to test my short velocity stacks on the dyno yesterday and here are the results using a modified ESS car. No bullshit was conducted in this test, we did over 20 pulls and installed the stacks in between. It even started to rain, so the gains might have been a bit higher due to the decrease in atmospheric pressure, but I digress.

The car came in making an average of 498whp @8psi, but let's call it 500whp, because it was a bit rich before we tweaked the tune. Once it was good and after a few more pulls, I opened up the plenum and got to replacing the velocity stacks. Originals came out no problem, but mine were a bit tricky to install due to the bellmouth and needed a swivel socket. Not a problem; got them in and thanks to two buddies, the lid was back on in about 23 minutes.

We did a few more pulls and had a gain of 10whp, but a loss of 10wtq. However, the graph had changed. The power graph shifted entirely and our AFR was slightly leaning out. Jailbreak Tuning Matt steps in, tweaks our tune and now we have a file to take advantage of the graph shift and clean up the AFR a bit.

Final pulls brought an additional 12whp and a regain of 17wtq. So in conclusion, after the stacks and a retune, we gained the following over the original tune:

+20whp
+7wtq"


If interest arises, I'll make more in sets of 3 for committed buyers. Thanks to everyone who came out to hang and help; a great weekend and a happy new year!





Original tune vs tune with stacks. Overall gains:


Original tune vs stack swap. No retune yet. Hp gain and Tq loss:


Overall comparison:



Links to bigger dyno photos:
 

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I made a few sets of my ShafroShortStacks back in December that didn't seem to gain much interest outside of the FB group. So I had a chance this weekend to put them on a dyno for some testing. Below is the story and results.

"We got to test my short velocity stacks on the dyno yesterday and here are the results using a modified ESS car. No bullshit was conducted in this test, we did over 20 pulls and installed the stacks in between. It even started to rain, so the gains might have been a bit higher due to the decrease in atmospheric pressure, but I digress.

The car came in making an average of 498whp @8psi, but let's call it 500whp, because it was a bit rich before we tweaked the tune. Once it was good and after a few more pulls, I opened up the plenum and got to replacing the velocity stacks. Originals came out no problem, but mine were a bit tricky to install due to the bellmouth and needed a swivel socket. Not a problem; got them in and thanks to two buddies, the lid was back on in about 23 minutes.

We did a few more pulls and had a gain of 10whp, but a loss of 10wtq. However, the graph had changed. The power graph shifted entirely and our AFR was slightly leaning out. Jailbreak Tuning Matt steps in, tweaks our tune and now we have a file to take advantage of the graph shift and clean up the AFR a bit.

Final pulls brought an additional 12whp and a regain of 17wtq. So in conclusion, after the stacks and a retune, we gained the following over the original tune:

+20whp
+7wtq"


If interest arises, I'll make more in sets of 3 for committed buyers. Thanks to everyone who came out to hang and help; a great weekend and a happy new year!
Great result. Curious. What about other tunes? Can Matt simply tweak the other tune for fuel, or do you need a new tune?

Regards,
Jerry
 

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Discussion Starter · #3 ·
Great result. Curious. What about other tunes? Can Matt simply tweak the other tune for fuel, or do you need a new tune?

Regards,
Jerry
We didn't need a new tune, only some tweaking. However, I would ask him as I know different tuners have different ways of mapping their files.
 

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Where is that S3 guy when you need him.
 
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On tirerack.com
Lmao.. I hope there is another thread with S3 in the title. What windshield washer fluid do you use on Dinan S3?

Anyway, I will most likely opt for a retune and give the stacks a go. Took the car out last night and she ran rich pretty much the entire time.

I’ll send you a link for 3D printed pistons.
 
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This seems like a scam to me. :read1:
 

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Excuse me are you lost? This is not hyper car forum.
I'm not lost. I'm just limiting my posts to things that are really important.

Btw...I still have an oil separator mount in my garage with your name on it.
 

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I'm not lost. I'm just limiting my posts to things that are really important.

Btw...I still have an oil separator mount in my garage with your name on it.
I’d hope you’d say Dinan wheels.
 

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Nice work Shady. Good to see someone properly show/describe the process to the end dyno sheet. I don't think anyone has ever posted results from just changing stacks either. The hp gain is a little more than what I would have expected and I'm surprised there was a torque gain even with the retune. Just goes to show that you need to use a tuner that knows the engine. I'm sure some people will install these and not regain or add all of the torque.

Full disclosure, I'm not supercharged, so I'm not interested in a set, but what's the rough price range? I'm just curious what the hp/$ is.
 
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Discussion Starter · #14 ·
Nice work Shady. Good to see someone properly show/describe the process to the end dyno sheet. I don't think anyone has ever posted results from just changing stacks either. The hp gain is a little more than what I would have expected and I'm surprised there was a torque gain even with the retune. Just goes to show that you need to use a tuner that knows the engine. I'm sure some people will install these and not regain or add all of the torque.

Full disclosure, I'm not supercharged, so I'm not interested in a set, but what's the rough price range? I'm just curious what the hp/$ is.
Thanks for the kind words, Tim. I wanted to make the results as thorough and clear as possible. People tend to quickly bash things they think they understand. Yes, Matt did an excellent job that day; he's my #1 choice of tuner for this car.

I currently have one last set and price is at $500 shipped. Next batch, if so, would be around $550-575.
 
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