Ritter v4.0

Chris-Send Boris some cup mufflers for re-testing with the X-Pipes.

Should these gains be more or less or the same for varioram cars?

Btw- whats the 4WD dyno drivetrain loss for those of us C4Sers?

SinVancouver

Boris, Do you have a stock CPU? Wondering if the results would be similar on an OBD2 car..

Bull

With the best of three runs on each test, I don't think there are likely significant outliers. But the sheets will tell.

A 3% increase in hp and a 1% increase in tq is nice because it assures me that there is no loss from stock cats due to design (which was the original question/concern, right?). I'm not sure I would call it a statistically significant increase.

Now Boris, you need to go out and buy examples of each competitor's bypass pipes and do a comparative test...JUST KIDDING!!!

993inNC

I think ViperBob told me as much as 25% loss!!! My car (now thinking back) felt like a pig compared to now with the tube disconnected and the LWFW. Amazing transformation its been. I have disconnected it so I can do my own dyno runs and back up my (DACH) stuff.

My guess would be a torque loss but hp gain with the cup muffs since you'll loose all restriction/back pressure. I get on all these different configs after the first of the year and we finish the current GB. Oh and you can bet there will be dyno sheet posts, good bad or indifferent. No snow jobs here.

jdistefa

Excellent point, in particular it suggests the possibility that brand new stock cats could perform very similarly (less gunk/binding/impeded flow). However, the results are still reassuring re. certainly no loss of power, probable gain, and all the other stuff.

With a sufficient amount of runs to collect enough data, both at baseline and with the DACHs, and someone to independently reproduce the results, you might find that these differences are statistically significant. But of course, that's very different than real-world relevant. But hey, whatever, they sound cool.

993inNC

I think we may just go ahead and make a set of the "other" widely discussed bypass pipes here. Whats there to a slightly bent pipe with a flange. And I will dyno those, we'll get to the bottom of this yet.

Now keep in mind on Boris' OBD1 ECU, it doesn't read after cat so it won't change like an OBD2 car and most likely won't yeild as good a result as an OBD2 ECU might. His cat is giving out raw power based soley on less than stock config restriction.

FlyYellow

i have a GIAC chip in the car.

The testing was done by DEVEK (a reputable shop). Marc is typically on this board so he can chime in. He did the testing....

As for whether the difference is significant or not. well at 3.2% you are correct that it is not signficant. i don't know if i would even feel it in a car. but allow me to put it another way 8 ponies is 8 ponies and when i compare it to other things that i upgraded on the car (i.e. the GIAC chip which produced 3 hp) i consider this to be a wortwhile upgrade. Not only for the horsepower & torque but also for less weight & the sound.

I wish there was more way to squeeze horsepower out of these cars, but i have yet to find it.

Cheers,
Boris

Cheers,
Boris

SinVancouver

Well def thanks very much for all the info.. I just got my car back from Steve W after having the CPU, top-end, LWF, RS Shifter, and a small 5hp widget all stuffed in there. The car went in with 115,000km's and came out feeling like a new car.. I had the 93octane program done and cant wait to finish this tank of 90 and get some 94 in there.. its hard to describe the difference.. best analogy me and my wife could come up with was that before when you put your foot in it there was a beat then the car pushed you forward.. now there is no lag and the car pulls you in all gears including 6th which it would never do before.

I have a X-Pipe set coming in Jan.. I cant wait.. !!!! I hope it all goes well with my OBDII car..

SinVancouver.

FlyYellow

what is a 5hp widget?

SinVancouver

Widget

Its a long story.. but I wanted a piece of art on my car now that I have decided they will bury me in this car

ppressle

Is this the mythical 5 hp piece that Mr. Linton mentioned???

chris walrod

Sure is. IIRC, the cup cars that use a similar piece to optimize crankcase vacuum also use a different FMS and RMS to avoid pulling-in debris pass the seals. Dont quote me on that but I remember some chatter about it at the recent PMNA open house.

Great stuff! Must be like a completely different powerplant

SinVancouver

As a precaution diff seals are used.

Mark in Baltimore

Nice work, Boris! Thanks for sharing it with the board.

Now, it would be very cool for us track rats if someone could dyno Chris' cat-bypasses with the ubiquitous Fabspeed Supercups...

Bull

That would be nice of you to do, but i was really kidding. You have a great product that does exactly what you wanted it to do....sound good, look good, save weight and not cost any power, possibly add power. Well done!