barrok69

I'm still rocking the stock airdam (~3inch clearance to ground), and have the standard stainless steel Corsa exhaust with Coated Kooks LT's and catted connections that are also coated. I've had these strips directly placed on the DS since I installed my DS in 2013. I'm on my 3rd or 4th set of strips now as I like to take new data points every now and then (Summer only car). Radiated temperature dissipates pretty heavily with small distances and the driveshaft is nowhere near the ground so asphalt temps really don't do much compared to the exhaust temps that are directly underneath the shaft. The shaft is most likely hotter in the areas where I don't have the exhaust ceramic painted and Titanium wrapped, but I was only concerned with the bonded joints at the ends of the DS.

The temp was my biggest concern when buying the carbon DS, but after 4 years of measuring I've yet to get anywhere near the bonded limits. There is a bit of airflow even at idle under there from the cooling fans (at least near the front of the DS), and the exhaust temps aren't nearly as hot near the Diff area to even worry about.

180degree front bond, and 150degree rear bond were my max historical recorded values at a road course track session last year. I verified the temps with a fluke infrared thermometer as well that I had on hand. That was driving mostly WOT for 20-30 mins at a time on a 90degree day in peak summer.

I've put new strips on since and 150 is the highest they've seen in long hot traffic conditions.

I think the coated headers/cats, ceramic paint, and DEI wrap on the corsa is key to the low temps I'm seeing. The Corsa exhaust is also pretty thick wall tube so that would help too.

I also have the DSS carbon shaft and it's only 3.25" so it's not as close to the exhaust as your 3.75" PST one. I'm not sure what exhaust you're running either. The Corsa is only 2.5". I can measure distances later this weekend when I get under there to take pics of my new welded Corsa with hanger system that I finally got done.

ls1247

iTrader: (2)

I'd say I've posted my fair share of constructive feedback on the matter...now it's Frank's turn

Frank, why would one of my driveshafts be long and the other short for this application? What is the optimal length for this driveshaft in your opinion?

Thanks.

FuzzyLog1c

iTrader: (4)

I'm wondering if our answers are different because you ordered the surface temperature Omega strips (e.g. TL-E-170) and I mistakenly ordered the ambient temperature strips (e.g. TL-8-170).

Until just now, I didn't notice the difference in the Omega part numbers. The Omega website doesn't make a real clear distinction either. You can also distinguish the strips by the shape of the "dots"--the surface temperature strips have round dots and the ambient temperature strips have square dots.

Presently I'm running a 2.5" Magnaflow. I plan to upgrade to a 3" Kooks X-pipe later this summer, which will get the Swain Tech treatment. I'll refresh the temperature strips before and after with both ambient and surface temperature strips to try and understand what is happening.

kra86

When I had bumped this thread from three years ago, I did not mean to arouse any bitterness but only to incite some sharing of personal experiences and attain enlightenment to my newfound CTS-V.

That being said, I drove around some more today, and I really want the driveshaft sorted as quickly as I can. I am hoping Frank would be willing to answer some of the lingering questions before they are lost in the fold.

Here is to hoping I can get a nice one piece driveshaft from DSS!

kra86

Frank? Where ya at?

ls1247

iTrader: (2)

I've asked some very specific questions of Frank that I'm sure he doesn't have any quick and easy answers for. They build a quality product but I have some very valid concerns about the correct length of my driveshaft...it would be nice to address this but obviously he has better things to do.

At one point in my first DSS driveshaft experience, I was standing in front of them with cash in hand and the time to do it...I encouraged them to put my car up on a lift and look at it themselves (I live an hour away) but they said they didn't have the facilities for that....that tells me it's been a long time since they've been under a V1 and they don't have any intentions of climbing under another one anytime soon.

I could be wrong about this but I was a customer having issues and I was willing to pay for their time...seems like the perfect opportunity to take an interest.

He did offer to make me a 2 piece carbon replacement for the 1 piece I was having problems with but by then I had tired of the process and took the complete refund and went happily with a Voodoo driveshaft. The only reason I wound up with the second 1 piece was in a swap I stumbled into.

All this being said, I just completed a 1500 mile road trip in the 8.8 equipped car in 90 degree weather and it was very smooth. My issues, which are admittedly more of an annoyance than a problem, only happen when its cold so I'll guess that it's related to the amount of poly in the car but that doesn't make my question any less valid.

From a performance standpoint, the one piece is probably not appreciably lighter than the factory 2 piece but I do like the direct feel and the simplicity of it. I would venture to say that if I tried different mount combinations, I could probably smooth it out a little more. As far as critical speed goes, I have no interest in going 170 in a Cadillac.

My conclusions, their v1 products are nice to look at but inconsistent in length. Their customer service is attentive but their follow through is poor based on my experience with miscommunications and missing parts. Their technical support is lacking as witnessed by this thread.

You get what you get but if it doesn't work, I do think they have the integrity to give you a complete refund. These are hotrod parts built by a small but busy boutique supplier who's more interested in the cutting edge than our "has been" stuff...I can't say that I blame them honestly.

Proceed with caution and confirm the length before installing.

FuzzyLog1c

iTrader: (4)

I wouldn't call DSS products cutting edge. They claim the critical speed of their 3.25" carbon fiber driveshaft is 250+ mph, when it's in the 175-180 mph range (I can't remember--it's been 3-4 years since I checked their math). By contrast, my PST V1 shaft has a critical speed of 9500 RPM, which equates to 215 mph on a 3.50 rear end with 26.70" tires. The advertised speed on DSS' site for their V1 shaft is actually for a 45" Mustang driveshaft and a 3.55 or 3.31 final drive ratio (I can't remember which). If they can't be trusted to do simple math right, I wouldn't trust them with my money or my safety.

MPH = (Driveshaft RPM)*(Tire Diameter)*(pi) / (1056)*(Rear Gear Ratio)

MPH = (9500)*(26.70 inches)*(3.14159) / (1056)*(3.50) = 215.6 mph

It's a lot harder to calculate for the DSS driveshaft since they won't give you the critical speed. I had to estimate based on the shaft length, shaft diameter, shaft wall thickness, properties of carbon fiber, etc. If anyone is super interested I'll pull up my calc. IIRC, the critical speed was 8100-8500 RPM. If it *is* 8100-8500 RPM, you get 172.5-181.0 mph on a 3.73 FDR using the above equation. I should also mention that when the V1 driveshafts came out, a lot of the DSS V1 advertising stuff was copied and pasted from the Mustang lineup. It took digging (mostly in the Mustang world, since there's better information there) and back-calculating for shaft parameters to figure it out.

It's important to note that critical speed is NOT the maximum speed you can drive on the shaft, as most companies advertise. As you approach the critical speed, shaft deflection will increase exponentially and you'll have to back off or blow up the shaft.

ls1247

iTrader: (2)

There you have it...the numbers don't work.