BC

You can do that? How much would it cost approx?

victor25

Yes I have a 3D printer. I bought it because making prototypes is was getting expensive. SLA prototypes would cost me like $500.

It is not a high end unit but I have it working pretty nice and have the speed is cranked up quite high too. ABS plastic is good to about 170 deg c

For Hans... No charge!! but Hans isn't just any Tom off the street

victor25

question involving the intake and tuning... and is there a thread on this?

So we all know that the drivers side of the intake cant breath as well. So has anyone ran an x-pipe with dual wide bands to see what the difference is between the sides????
With stock exhaust.... if 5 & 8 are getting less air, causing them to be rich, the LH will adjust all the cylinders to find balance. Making the other cylinders a little lean.
But with an X-pipe the O2 sensor is usually only in one side, and usually the 1-4 side. Which is the good breathing side and you are only tuning to that. So that means 5 & 8 are running rich and being ignored... yes?? which leads me to another quandary... if and x-pipe with cats gives more power, could that be part of the reasons why, other than just better exhaust flow?
Ok back to my original thinking. If running an x-pipe with dual WB sensors, then one can log and capture a lot more data. Example... right bank v left , and a much easier ability to dial in the injectors to the intake & cylinders

Hey.... maybe I should just get long tube headers and run 8 Wide bands haha

BC

Todd

Rob Edwards

Yep:

https://rennlist.com/forums/928-foru...ds-garage.html

(Pic shamelessly stolen from above thread, Erik, holler if you want this image taken down...)

Mongo

I wonder if I can smog that setup.

victor25

And I quote..... "Sweet Mary mother of god" and "Holy Christ"

Pretty freeking sweet Now how do we get our hands on the output results or logs ??????????

Although it may just be easier us to keep bumping Hans to get those intake ports made.

worf928

I just spent a couple of minutes zoomed way-in and scrolling around that picture. There is A LOT going on under there and not just the O2 sensors.

ptuomov

Todd Tremel could take those O2 sensor data and/or his fuel trim data from the car with the stock intake manifold and send it to Mike Simard. Then Mike could make the best, four pattern cams for smog (il)legal engines that have to use the stock intake manifold.

The end package would have
- A profiled intake manifold spacer for the driver side
- Porting instructions for the intake manifold
- Lighter hydraulic lifters
- Dual pattern intake and dual pattern exhaust cams, designed to give better power with stock intake and exhaust manifolds while still passing the tail-pipe test
- Stock looking higher pressure FPR or larger injectors
- New maps on a chip and/or ST2 file

I think (but again can't prove) that one could get a quite a bit more power from the S4 engine with this package while passing the tail-pipe test.

To bad none of this is commercially feasible, it's a recipe for losing money. But for some more popular and less complex car this sort of package would have demand.

blau928

This is an old pic from 2004... This allows the LH narrow band to sample from all 8 cylinders at once..

There is another O2 bung on the other side to allow a wideband for tuning/datalogging.

Future version will have two O2 bungs in the header collectors for dual widebands for use with the Motec, and at that time the plan is to also plumb in 8 EGT probes in the runners for tuning. (The X will also be replaced with a better one tuned for engine specification..)

It is very easy to place two O2 bungs for the LH and a wideband in the middle of the X so the LH can get a good signal, as well as the wideband.

Just my $0.02

Lizard928

Tuomo,

My cams have passed smog tests without any issues.

ptuomov

I am sure they are just fine.

I was just making the point that to get the absolute maximum smog legal performance out of the S4 engine with the stock intake manifold and stock computers, one could probably get some gains from well designed quad pattern cams. You do agree with me that we should "grind" a later IVC for the long runner cylinders and an earlier IVC for the short-runner cylinders, right?

If you have some blank cores left at Colt, and if you can get the individual cylinder wbo2s or port pressure traces measured, you might want to experiment with this just for some ghit and shiggles. At a commercial loss, of course.

PorKen

RE cam tuning, -3° appears to be the max for S4 cams, measured by airflow (MAF volts).
Only the dyno will tell, but it looks like there should be more peak HP with a minor loss in peak TQ.

More retard raises the rpm point of overall airflow, but does not increase the peak airflow (flattens out).
Increasing retard proportionally reduces airflow over the first torque peak. (I tried up to -6°.)
Raising the rpm point too far requires retuning both fuel and ignition maps.

(In my testing, S3 cams made the most HP at zero.)



How about a installing a resistor on the 5 and 8 injectors?

Would have to do some spark plug color checks to see how much to use?


Note the LH monitors injector voltage and compensates for under voltage with a longer pulsewidth.

ptuomov

I think that at least after installing the spacer, the long-runner and short-runner disparity is rpm specific. A constant resistor or a slightly lower flow injector isn't going to cure that.

Lizard928

Grinding the cam with later and earlier intake valve timing could even the flow yes. But the amount of math and testing would be insane!
Plus the variances from manifold to manifold are fairly large. So this would have to be done on a car to car basis.