wino5150

How many here have DL's version versus 928 Motorsports'? Not trying to stir the pot, but trying to help the board make a conscious decision on which product is preferred and why. Or are they virtually identical and price is the only critical difference?

Happy New Year to all...

Roland
'91 GT, RMB, no Xpipe (yet)

Jim R.

For what it's worth, I have the motorsports crossover with cats, my GT resonators, and a RMB. Sounds deep at idle (not too loud), but great at WOT. My wife deals with the noise well, we have had louder toys and this is a good compromise. I may pull the cats and put in the bypass pipes just to hear how loud it is, but I don't need any more "attention" than I already get.

With the cats, a Murf stage 2 supercharger (30# injectors) it has passed NY emissions on a rolling road simulating uphill loads and acceleration with both the factory cats and the motorsports crossover/cats. The smog pump is disconnected and not needed for the new cats. I would expect a stock 928 to pass emissions easily.

Just another reference point and a very happy customer.

Jim

Ketchmi

Hey Roland, we supply 928 Motorsports with X's and Y's. They are a reseller for us so yes, I'd say they are identical.

wino5150

Is the sound that much louder w/out cats? I plan on purchasing the straight pipe version, as I have an 'in' with my BMW mechanic who does inspections. That being said, I don't want to be driving a panzer through the neighborhood, but at the same time; I don't want to spend the money on new cats and want the full power of not having any cats. Thoughts??? I'm not concerned about sound at WOT or let's say over 5K, since around town I can easily short-shift to avoid increasing dB's.

Thanks again to all...

Ketchmi

A 91' GT with the small resonators will be quite loud with an RMB and a catless X. If you keep your stock rear muffler it should sound pretty good, maybe a bit quiet...

wino5150

Thanks for the info...I know where I'll be buying I guess. I still have my original GT muffler, so maybe put it back on for 'off track' time and reinstall the RMB when I head to the track? I think I've been told around 5-7 HP gains with RMB...yes? Not that that's going to matter too much, but hey; I've already got the RMB, so might as well use it eh?

Thanks yet again,

Roland

the flyin' scotsman

Roland...........up until very recently there was no options available for the OEM cats as the previous X builders all completed their manufacturing.

Motorsport (Dave Lomas) made additional upgrades to the Ott X with great HP improvments while at the same time 928 specialists developed their own X and somewhere in the distance Devek developed and built their own.

Quality issues from a supplier prevented 928 specialits being available while Motorsport got their product to market and us consumers were happy. Subsequently Specialist fixed their quality issues and Devek produced their version giving many options where there was once very few/none.

I now understand the Motorsport X to be sold be Dave and his company as well as 928 Motorsports (yes its confusing, 2 companies with very similar names).

Not sure about the Specialists version and Devek have recently moved again and fallen off the map.

If you search enough you'll find glowing reports about all the X products; the issue now is again availabilty as in the Supercharger but thats another story and a half.

Ketchmi

I'm still willing to pay for a public dyno test session with any competitors...

Also, we have plenty in stock and ready to ship in all configurations.

I do not have any dyno testing with the RMB. I do not know if it improves horsepower any at all but it sure sounds good!

Shane

Really? I need to redyno Helmut! I have an Ott pipe with 928 Intl RMB.

the flyin' scotsman

I wish I lived closer.............very curious re. your X with larger resonators and a RMB; hp and noise.

Mrmerlin

I have the X with no cats , the GT resonators and GT rear muff it sounds good , I tried it with the RMB as well, waay to loud for hiway driving makes too much internal drone, with the GT muff its is golden. Plus the extra kiick in the pants is worth it I can really feel the extra 25 HP after removing the original header/cat system

wino5150

Thanks for the all the info, and I guess I'm at a loss for what to do with my RMB that I just bought from Devek last year. I guess my thinking is that if the RMB adds HP then why not at least use it for the track, and put the original GT muffler back on it for street/home use. Make sense, or should I not fool with the RMB for a stinkin' 5-7 HP. And for that matter, does anyone have experience with dyno tests to show if the RMB is any improvement over a GT muffler or just for sound quality?

Best to all...Roland

'91 GT, RMB...soon to have x-pipe

H2

This is an interesting discussion....and dyno tests are important in supporting any claims. I put an RMB on the '85 and it "sounds" faster but I'm not sure it really made all that much HP difference, except for less weight. I hope I'm wong. I want to outfit the '88 differently....with dyno numbers to justify the costs...but still keep great sound. This thread is giving me some good ideas.

Harvey

the flyin' scotsman

I traded my RMB and still have the stock rear muffler in the garage. Keep your RMB on the car until you fit the X and hear for yourself..............your car becomes very free revving but hold onto your ears,

James-man

Hey there WINO!

Less weight is reason enough to change the RMB - a good time is during your pre-tech inspection. It is fun to be loud. You cannot rely on cumulative benefits of individual modifications.

But for a guy that does not bother to remove his spare for DEs, you probably do not care about the weight anyhow.