[Calli74]

Appreciate the opinion / but not looking for FI or Short stacks. NA build!


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[alquazi]

Tony has assured me they can and will run the TB sets for us, but the stacks are the real issue and confer the vast majority of the real benefit. I have a set of Dinan stacks out to my CNC guy for evaluation. We shall see.

Very much interested

 

[manny1424]

Any update on this?

 

[herrubermensch]

I hear there is very little benefit to running aftermarket ITB’s on what is already an ITB car. Similarly, velocity stacks lead to detriment and loss of power in a non-FI car.

Short Velocity Stacks on S/C results!

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...

www.m5board.com

SpeedHaven Racing

Just false, I'm afraid. The Dinan velocity stacks are one of the most important features of maximizing the output of a NA S62. The Dinan stacks are the product of hundreds of hours of dyno time in maximizing the output of the S62 for the Rolex 24 Hours race. The larger (52mm versus 48mm) TBs with which the Dinan stacks are paired are much less important, but still add something. But the stacks are absolutely critical. I agree that "shorty" stacks likely lead to a loss of power in a NA S62 if that's what you mean. In an FI car, the "shorty" stacks are ideal. But this thread is about the Dinan velocity stacks, which are anything but "short."

--Peter

 

[herrubermensch]

And just to be perfectly clear, we have scanned the Dinan stacks and are modeling them in 3D so that we can generate aluminum molds from which to make CF versions of the stacks for use in Partee Racing's E39 M5 endurance race car. We MAY seek to make them a tad longer, but don't want to mess with Dinan's success. We will assess whether it makes commercial sense to manufacture them for sale. I suspect they will be too expensive for anyone to want them!

--Peter

 

[BoDangles]

Just false, I'm afraid. The Dinan velocity stacks are one of the most important features of maximizing the output of a NA S62. The Dinan stacks are the product of hundreds of hours of dyno time in maximizing the output of the S62 for the Rolex 24 Hours race. The larger (52mm versus 48mm) TBs with which the Dinan stacks are paired are much less important, but still add something. But the stacks are absolutely critical. I agree that "shorty" stacks likely lead to a loss of power in a NA S62 if that's what you mean. In an FI car, the "shorty" stacks are ideal. But this thread is about the Dinan velocity stacks, which are anything but "short."

--Peter

I remember there was a big thread about FluidMotorUnion putting shorty stacks and meth injection in an S65, and losing horsepower. That could be where the idea that "stacks are detrimental" comes from.

 

[DesertTech]

Peter is right, there is so much more testing behind the Dinan design it has more to do with how they are tailored to the S62 than just opening up more space for airflow. In an old interview with Steve Dinan, he even said their first attempt was to just enlarge the stock system and it lost power across the board. They slightly modified the shape of the intake runners and while not carbon fiber such as Peter's, had great success there. The length of the runner generally determines torque, while also protecting the natural valve resonance of the engine's harmonics. Resonance is less a factor in an ITB car than a single throttle car with one big manifold but it can still be tuned somewhat!

If cost is an issue, best bet is to shorten the stock runners by hand while retaining some of the overall shape. A few high hp engines out there have this design. If you want to go one step above that, but a step below the superior Dinan/Peter design, Wilson Manifolds could help enlarge the stock TBs but you'd be on your own for trumpets!

Also, maybe Peter will make some of these in aluminum for all of us general public folk! Will stay tuned! 😛

 

[manny1424]

Yes hopefully Peter will consider making an aluminum set I am sure there are plenty of members here who would purchase!!!!

 

[herrubermensch]

VAC has agreed to make the larger TBs for us once we get the stack situation resolved. I'm not sure that making the stacks out of aluminum would be cheaper! We are having to make molds out of aluminum for the CF stacks, and that's where most of the cost lies. Generating CF versions after the mold is made is much less expensive, but we have to recover the cost of making the aluminum mold in the first place.

 

[Calli74]

Anyone have a solid connection with Dinan? Would it be feasible to see if the diagrams/tooling used for stacks is stored away in a warehouse? [emoji120][emoji2371]


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[herrubermensch]

Anyone have a solid connection with Dinan? Would it be feasible to see if the diagrams/tooling used for stacks is stored away in a warehouse? [emoji120][emoji2371]


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Yes. We do and are in discussions with him about these things. Unclear whether Steve still owns the rights to these or whether than ran with Dinan when it was sold to the PE shop. Regardless, the scans of the stacks give us all the information we need to reverse engineer.

—Peter

 

[herrubermensch]

Kind of in this same vein, we are having a number of CF lower plenums made that bolt directly to the TBs and eliminate the thick TB gaskets or plenum plates. They each will have a machined aluminum ring on them that accepts the stock plenum gasket and top. Because our endurance M5 has a standlone ECU and does not use the idle actuator, our plenums lack any connection on the front for the idle actuator hose, but such a connection easily can be added using a AN connector. Same with respect to the air/oil separators. Moreover, these do NOT make use of the stanchion connections inside the plenum, meaning the plenum top connects only along the perimiter, making these inappropriate for use with any form of forced induction. In short, these are race pieces and as such, would require some modification for use on a street S62. That said, I intend to make those mods and use one of these on my son Sam's E39 M5, which is undergoing a complete renovation. Here is a pic of an earlier version without the connections on the front for the air intakes. Our version obviously will have connections on the front for the air intake! Finally, these are VERY pricey, so our initial run will be only four, two of which I intend to use and two of which will be for sale to those who want the absolute best.

--Peter

 

[Calli74]

Fine - I’ll be a your guinea pig for free! [emoji23][emoji1787]

Why not get a better baseline for the regulars here - pulse an interest in purchasing - then build a group buy price based on interest and economies of scale?


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[herrubermensch]

Fine - I’ll be a your guinea pig for free! [emoji23][emoji1787]

Why not get a better baseline for the regulars here - pulse an interest in purchasing - then build a group buy price based on interest and economies of scale?


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Because I’m not building anything for the express purpose of selling it. I’m building everything the way I want and need it for my endurance racer, but sometimes, I have to make multiple copies of something to get it done, so I have excess for sale, such as here. And sometimes people want exactly what I want, in which case I’ll have some extras made and sell them.

—Peter

 

[Calli74]

Please note I’m cursed with a sarcasm gene.

That said - I’m also cursed with FOMO (fear of missing out) so I’m always interested in solid NA build options, that are reliable.


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[herrubermensch]

Sorry! I missed the sarcasm (obviously)!

 

[gsfent]

Sorry! I missed the sarcasm (obviously)!

What, no sarcasm font????

Regards,
Jerry