UpFixenDerPorsche

Ptuomov, I understand this non-linear relationship (and wish I had the answers), but all I can do is to report what is happening with my engine.

You can see the simple construction of the pre-TB splitter, so why not make and try one for yourself? This would give us an idea of the effects of the butterfly turbulence shadow only?

At the very least you'll lose nothing, and at the best you'll get some gain for very little cost and effort.

:-)

UpFixen.

UpFixenDerPorsche

In this case Mark, they're both sides of the same coin, IMO.

UpFixenDerPorsche

Hi Greg,

I would agree with you, but for one thing: the new, instaneous throttle response.

I have my S4 auto for comparison. Pre mods, both had the same response to the long slow accelerator action, c/- that clever cam action to slowly open the butterfly off idle. Performance was there in both, but you just had to get used to the long accelerator throw.

Now, if I dab the GT accelerator by so much as 1/2" - 1", the car jerks forward. You could be forgiven for thinking I had by-passed the cam and connected the accelerator cable directly to butterfly.

At the time I had a 1600cc Ford Laser as a DD. (Mazda 323 in the U.S.) No intermediate cam action before throttle butterfly. Touching the accelerator gave an instantaneous response. Always took an adjustment when switching between cars.

The GT now reacts as instantaneously as the Laser did (but with more grunt), ie it feels as light and frisky to drive as the Laser, and this is what puts the grin on my face even on the shortest drive.

It's also why I know what I've achieved isn't the result of an accidental fix, and therefore why I'm sticking to my guns on this. I've owned my S4 since mid-2000. and have diagnosed and solved the typical array of problems, so it's not as if I'm a babe-in-the-woods here (although far from your level of experience).

I'm sure that someone, somewhere will have been following this thread, and will reach that "OK, I'm sick of this" point, and see for themselves by doing the mods.

Would love to hear from you when you're finished.

:-)

UpFixen.

ptuomov

How does the LH's and EZ-K's acceleration retard and enrichment functions behave in the knock sensor error mode? Do they pull even more timing when you floor the pedal, on top of the error state normal ignition retard? If so, that could explain why fixing a sensor might also improve the throttle response.

jcorenman

The LH acceleration-enrichment is independent of the EZK, so would not be effected. When the EZK detects a hall or knock-sensor failure then it pulls six degrees of timing from whatever timing value is calculated from the maps minus transient retard etc. So yes, throttle response could be greatly effected.

Also the MAF only samples a small part of the cross-section, so changing the flow distribution through the MAF (e.g. by adding a vane) changes the measured airflow and changes the fueling. The two screens help, but only to a degree. Fueling of course can also have a big effect on throttle response.

And the MAF signal of course is fed to the EZK as the load signal, which-- along with RPM-- determines the base timing.

So changing airflow distribution through the MAF potentially changes everything.

For meaningful comparisons of any change I think monitoring the LH and EZK would be essential, as well as re-mapping the fuel maps for anything that possibly effects airflow distribution through the MAF.

UpFixenDerPorsche

Jim, the vane is downstream of the MAF.

Cheers

UpFixen

mark kibort

actually, two different functions... you reduce the turbulence that would normally occur at the end of the TB place, and then address flow turbulence /separation and inefficiency of the flow turning a corner.... but yes, if it is all blended together, all the better!

Marti

So after many many pages of talk, debate what's the outcome of producing a manifold with prospects of increasing power?

I know Greg Brown is developing a manifold to put into production and other people are spending time and effort on one off's

So unless I am missing something I'll only be able to buy Gregs?

Greg - when do you expect to have this ready ?

GregBBRD

Spare time to devote to this difficult project became an issue. Both Hans and I devoted many hours of thought and work on the "base" pieces, neglecting other priorities (mostly Hans making changes to satisfy both of our perfectionist personalities.) We both needed a "breather" to catch up on other things.

And the projected cost/investment of this crazy undertaking continued to grow....

We are just now back starting to look at the final pieces....which are not trivial, in nature.

Hopeful to have the first pieces to test for the fall, now.

While it is relatively simple to "cobble" something together, it's more difficult to test and massage that crude effort into the best possible product.

The "cobbled" up effort took over five years...

Like everything I've designed and built for these cars/engines, perfection takes lots of time and costs huge dollars.

hans14914

Greg is just covering for me. I got sidetracked trying to finish up all the parts for the twinscrew kit. Now that its wrapping up, I am looking back at the normally aspirated manifold design.

We had a delay at the machine shop that I selected for the first run of parts. Their CAM workstation went down, and they lost a lot of production time, so our smaller projects got pushed to the back burner. I spoke with them yesterday (about supercharger parts) and they said the fuel rails and insulating spacers are machined, and they were starting to cut the intake manifold stubs.

I am hoping to pick them up next week, and I will get them on an engine and start mocking up the plenum. I have a couple basic designs on the plenum and runners here, but I want to test everything in the car to make sure we clear all the plumbing and wiring.

So, I am back on it. *Shameless Plug* - keep your eye out for a new twinscrew thread shortly. As soon as I get the pricing back from the machine shop, I should have some preliminary numbers for the initial post.

GT6ixer

Greg, is your manifold designed to work with all motors or just the 32V 5.0L motors? Sorry if this has been asked an answered but I thought it would be quicker to ask again than trying to search through 54 pages of posts.

Ducman82

there are plans for a 16v version as well. but they are next...

GregBBRD

There will be a 5.0 liter version. We need to do some testing and some "back to back" comparisions to make sure the 5.0 version has the correct throttle opening, runners, and plenum volume.

GregBBRD

And I'm guessing that this twin screw kit will be a work of art.....not built out of pieces from Home Depot, but a kit worthy of being on a 928!

Marti

Hi Hans and Greg

This is getting exciting as you get closer to production. Just to let you know that I am watching this closely and am rooting for you to carry on !

There is am market out there that wants this to happen.

Regards
Martin