Yep, sometimes that transition sound gets a little annoying, especially with how easy you can go into boost with the radix.

The best I can describe it is a lower frequency version of the radix whine, more of a whrrrrrrring noise.

Some days I love the radix noises, some I don't. These days I'm like that with any modification though. My headers get on my nerves too because you can hear so much of the valvetrain noise now compared to the stock manifolds. The noises the radix make should not turn you off to getting one, it truly is a great setup.

 

hey bud, part of the deal is how low in your rpm range the radix starts working, and much of that is the best thing about it too.

I am in no way trashing the radix, just saying what I've said above.
the thing kicks in around 1500-1800 rpm, depending on load ,which is one of it's best features but at the same time this is a dd rpm range that it makes the noise.

the fact that you can do Radix and not break/melt pistons is by far the biggest deal for daily driver imho

hopefully the tvs may not have that weird noise and be still deliver the rest as expected

 

We have seen the issue you are refering to on dyno engines. It is not caused by anything with the intake manifold. From what we have seen and the issues we have seen with Speedvision road race engines is that the coolant flow around cylinder 7 is not optimal. This cylinder runs slightly hotter and is more prone to knock and pre-ignition. The intake manifold on these engines move only air. Each injector is squirting the same amount of fuel. If there was bad intake manifold distribution, #7 would be getting less air and would actually run richer. Lean can be misdiagnoised for failures due to knock and pre-ignition. If #7 was actually running lean, that means that that cylinder would actually be getting more air or flowing better than other cylinders. I highly highly doubt that. The other thing that doesn't make sense is that with a supercharger, it evens out the manifold distribution with positive pressure. When you pressurize a vessel, you get the same pressure in all corners of the vessel. In Vacuum, nothing stays the same and you get air distibution problems that compound with high overlap cams that pull residual exhaust gasses up the intake tract. A NA manifold with bad distribution and a high overlap cam will dilute and lean out some cylinders with less clean air not pushing the dirty EGR gases out.

Back to the supercharged application. So if all corners of the manifold are pressurized the same, when the intake valve opens (variable changing to fixed orifice), the mass flow rate of air (and subsequent fuel in air stream) will be constant.

 

that is very good info from a knowlegable source, I beleive you work for w2w?
my desription of lean/rich may not be technically accurate but the
idea was that #7 seems to end with more air -less fuel causing the piston failures in f/i engines. it may well be as you say, cooling in the block causing the problem not air distribution.

beyond that, the fact still remains that the radix engines don't seem to have this failure, many of the turbo guys have had piston failure, as well as ati.
vortech, whipple etc.
i ran 9psi on mine and i ran it hard with no issues other than the tranny
anyone care to quess as to why?
could just be the fact the radix has an intercooled intake...

 

Your correct, I do work for W2W, I suspect that Magnacharger has done more work on their cal than the others you mentioned and therefore have better detonation control. Of course I still think our calibration is superior, we sent our system engineer and our calibrator with an LQ9 truck to the GM Desert Proving Grounds for 2 weeks to fine tune our hot weather cal., I can't think of to many other aftermarket companys which will do something like that.

 

MagnaCharger, Power Works (Mahle Powertrain). both do this for their calibrations. I agree, MagnaCharger spends ALOT of time on the calibration and driveability with the supercharger. That is what makes them the best all around FI option available on the market today.

 

Brian, you are one of the best authorities on FI.

There is a good thread above

fill us in

https://www.performancetrucks.net/fo...d.php?t=392258

 

True, but pressurized air isn't always getting delivered at the same ratio as the engine is using it. (pressure spikes and drops) So I would think that Stagnation pressure could play a part in over pressurizing a cylinder, right?

Seams how the radix is a positive displacement pump that is coupled to the engine directly, it in theory would have more of a static pressure and less chance of stagnation pressure accuring.....


I maybe WAY off on this, I can't remember that much of high school and "Principle of Technology" class....

 

It looks like you guys use diablo for your 07s, have you had any trouble with there product and fried PCMs? My buddys 07 fried 2 and diablo after looking at the first one sent it back and said have the dealer tow it and fix ,there was a glitch in the tuner/handheld and they fixed it.They wouldnt do anything for my friend and had no proplem having GM eat it. 2 weeks after he got it back form the dealer he tried it again with the new tuner they sent ,fried again.diablo would do nothing ,he had it towed dealer fixed it and is very suspicious and so is GM ,they GM,will be cracking it open they said.

 

So lets get back to the 6.2, any aftermarket support yet? I'm done with my Titan since cracking a piston after adding Mp112 S/C.