moosestang

I know the difference, I just don't think it matters that much. Do you have some IAT temps from a tvs?

moosestang

I know the difference, I just don't think it matters that much. Do you have some IAT's from a tvs to compare to a whipple, kb?

dlazrael

I don't pretend to be an expert - but I also don't take everything I see here verbatim.

I've done some pretty exhaustive research, reading everyone's advertisements and "FAQs" and taking a little grain of salt from each. From what is supported by several independant sources (which may or may not be seeing kickbacks, thus adjusting their reliability) the twin screw makes the least amount of heat from te TVS/Roots/Twin Screw combination, for a multitude of reasons (Some being the formation/shape of the air charge, the way the gears function etc).

My point is someone stated, "KB run hotter because they don't have a bypass valve like teh TVS etc." [paraphrased/inferred]. I was pointing out the fact that this in fact was not true and it has a bypass valve (now). I am not comparing older models, just what is available now....

I have been looking long and hard at S/C's. Through research I have determined I want a "roots STYLE" blower... I debated between Whipple, Roush, KB and Edelbrock. For those of us on the street, ALL of our blowers are going to be "heat soaked" unless we are doing a cold run... so that also isnt a valid point. I made my choice (Still saving, now its delayed again due to the pending federal furloughs... being federal I have to save some $ to make up for that) for KB, for looks, for teh [lack of] sound, etc. But like another member pointed out, for the most part, they make near the same power, and at near the same cost, it's really just buyer's choice... Besides, if/when I drag the car, I don't plan on making so many rapid passes that the 'heat soak' is really an issue...WHen I raced my old car (03 Mach I N/A), even on test-n-tune nights there was still an average of 30-40 minute downtimes between runs.....

Now, some factual IAT variance evidence coupled with ET/Comp runs to show the actual loss... thats is a different story.. And once I get everything all set up, I'm going to make a few dozen passes to get a feel for my car and once that finaly happens I'll be sure to post up the info as best I can...

908ssp

Absolutely on a 450rwhp street car the KB is running 20 to 30 degrees hotter than the old M122 Modified Roots. There is a reason every car manufacturer chooses an Eaton for their street cars.

Diabolical!

I'm not studied enough to argue this with numbers, but something isn't making sense. The reason so many Lightning owners first started swapping the eatons out for whipples/KBs was high IATs. Same thing with the 03/04 cobras and 2007-up GT500s. People replace those eatons because they run so hot. There are an awful lot of homeless factory eatons with whipples and KBs living in their old houses.

Now, having said that, I can say from personal observation that the TVS does run cooler than the KB, but so does the whipple. All of them will heat soak over time, but without a doubt, factory eaton superchargers heat soak more than any other form of FI I've ever seen.

Diabolical!

OK, going back and focusing on this. None of the blowers in question are really stretching their legs at that power level (assuming we're talking 4.6l 3V Mustangs). My time spent in performance shops has shown me that the more you push through a roots, the hotter it gets. Twin screws handle it better.

908ssp

My buddies 650rwhp KB could hardly get out of the neighborhood without the water getting hot. Another friends Whipple was so hot after cruising Woodward he couldn't run another car till it cooled down. Mean while my Eaton is 10 to 20 degrees over the ambient air temperature. Racing they would run cooler, on the street they don't.

Roots compressors don't actually compress any air with the bypass open. A screw blower compresses the air in the screw so the air is hot before it is released into the manifold after it goes through the intercooler and only after that does the bypass valve release the pressure. So the heat created in the screw is partial transferred to the intercooler reducing the inter-coolers thermal capacity to remove additional heat. In other words driving normally with a screw blower preheats your intercooler water. A Roots blower doesn't do this since there is virtually no compression when the bypass is open which is most of the time.

TVS is a modified Roots from what I have read it should be even better than the old M122 which is still a good street blower.

moosestang

Always assumed it was cheaper to make a roots blower. Vortech seems to agree.

http://www.vortechsuperchargers.com/...em.php?gik=749

Same reason you see more factory turbo charged vehicles.

I hate to post data from kenne bell's website, because most of their tests seem biased.

http://kennebell.net/KBWebsite/Commo...romcatalog.pdf

I wish I had my IAT sensor after the blower, so I could post some normal cruising temps and full boost temps. I don't have a bunch of buddies with 600hp street cars, so i can't argue 908's experiences. He must be in some super street car gang.

moosestang

Since we are discussing factory superchargers now. Why do you think the Ford GT came with a twin screw?

Diabolical!

I guess that's all that matters to me. Figured the cobra jet was wearing a whipple for a reason.