Harrop Smoothie D-Box? and misc issues
 

Heyo - does the Harrop supercharger kit require a Smoothie D-Box like the Edelbrock kit?

Also... are there any known issues with the Harrop kit? Reading through all the ownership threads. It looks like

Edelbrock bypass valve is known to fail (repeatedly)

JRSC Rotrex unit reliability is iffy

Are there any issues with the Harrop kit I am missing?

D-Box: I haven't heard of anyone of the Harrop customers using one. In fact, I am of the opinion that the pressure pulses can be reduced significantly and pneumatically by using a remote-mount MAP sensor with a pulsation dampening chamber inline with it.

I am currently in the middle of experimenting with certain parts and materials to address this and have a working prototype, but I have yet to install my Harrop on my car yet to test it out.

As for any known issues: I haven't heard of any. It seems to be as reliable as a Lexus, which is one of the main reasons that I chose it for my car.

Haha I just went to this subforum to check on your progress and found this thread. I guess it is still in development.

To the OP, I don't know of anyone with issues. The kit suffers the same issue, but maybe less because the sensor is lower in the runner. It can be sorted with tuning or with a mechanical filter, but otherwise, it isn't really a major issue. I don't have the Dbox.

Harrop doesn't need a D-box. Neither does the Edelbrock, with CSG tunes.

Edelbrock's bypass has been incremented and is no longer an issue

JRSC Rotrex kits are easily THE MOST Proven kit on the market. The most popular kit is bound to have the most failures because there's more of them out there. As an actual percentage, failure rates are tiny.

I reached out to Neal @ Racer's Line who helped develop the CARB tune (I learned). He informed me that the Harrop kit uses a separate IAT sensor and the stock MAP sensor so it does not require a smoothie box.

Hey Mike, I'm inclined to believe you given your experience.

In terms of reliability do you think the C38 running on a CARB tune would have a longer life than a C30? Because it's not being stressed as much? Waiting for a new unit from overseas on top of a warranty claim just seems like a huge headache I would like to avoid.

Those bearings are designed to spin at high RPM. There is no "less stress" with the C38, but I do see units frequently go under-maintained.

Undermaintained as in not changing the oil every 50,000 miles? I thought Rotrex was maintenance free outside of that

or 2 years, and making sure the fluid level doesn't get low.

Many folks don't do that.

It depends on the tuner, what the tuner is using to do their tune and your setup. Some tuners prefer to tune off a MAP sensor, and I don't know the limits of the MAF sensor for tuning. Maybe it has no limits, but I bet there is a limit.

From what I understand, the Harrop kit uses the stock MAP sensor and is running a tune off the MAF readings. The stock MAP isn't really designed for boost, so anyone getting a tune based on the MAP sensor needs to upgrade, which was me, and because I am running more than the stock pulley, the entry level MAP sensor at 11psi wasn't enough, so I am on the 45psi sensor.

The downside is that the MAP sensor does see fluctuations, which I hear tell from others can be tuned out like Mike said, but I don't know if all ways of tuning it out is the same or equally safe or possible at all boost levels or whatever. Best thing is to find a tuner, and then ask them.

Uh, your tuner specifically had me make a remote MAP sensor adapter for my Edelbrock tune due to large pulsations that even the D-box couldn't pull out. It made a huge difference.

What do you make of the 100k Edelbrock oil change interval? Seems sketch to me tbh.

I'm lame and would probably just use the CARB tune for whatever kit I choose.

Got a picture of your setup?

Yeah, @B T and I traded a few pictures of the setups that we have. I've actually got mine installed on the stock manifold right now just to make sure it would work with normal vacuum, and I have had no codes pop up since remote mounting my MAP sensor. So far so good.

I've got some pictures of it but I wanted to pull it out and set it on a table to take some better pictures of it seeing how it's currently swung around 180 degrees and zip-tied in place hiding the fitting at the port. I'll get that pulled out and get those pictures posted some time tomorrow.

I also have an alternative part to use for a chamber that I would like to experiment with, but it's pretty pointless to do until the supercharger is installed.

B T's setup plugs the stock MAP sensor port on the runner of his Edelbrock kit with a plug fitting on the chamber itself, then he mounts his MAP sensor onto his chamber which is then plumbed to the rear pressure tap that Edelbrock uses for a boost gauge (for testing purposes?) with some fuel hose. It differs slightly from my design, but since his setup seems to work just fine for him, I can predict that my setup will also work.

Oh, and I also ran this idea by Zach when we were doing my flex fuel tune who then told me that B T was doing something similar, which I already knew at that time, and he agrees with both of us that this is a good idea.

Since Zach pretty much developed the Harrop CARB tune, he could probably be able to tell you if he used MAP sensor smoothing in the tune or not. But even if he did, adding a separate remote mount MAP sensor feature to your setup shouldn't hurt anything, (and will probably help).

The MAP sensor is ported to what is usually used as the bypass valve vacuum line. The bypass valve itself is run off the brake booster line. This solves 2 problems at once, the pulsations and bypass valve failures.

So on the Edelbrock thread here,

https://www.ft86club.com/forums/show...93718&page=285

with the conversation had between posts #3984 to #3991, is that how your setup is, more or less?

There was a "capped off port" (post #3991) that is used for a boost gauge. Is that what you're using? Sorry, but without pictures, it's difficult for me to visualize, seeing how I don't have the Edelbrock kit myself.

yes, the post in #3988 actually shows one of my CNC remote MAP sensors(bottom left) and the best way to run it for better MAP signal and BPV longevity. I haven't opened any capped ports on my supercharger and neither had that one. The port on the back of the supercharger is where the edelbrock originally got its BPV vacuum signal. A boost signal could be obtained from the same line as the MAP sensor without opening another port though.

Need =/= want.

Different setups =/= different flow/pulses.

The nice thing is that Ecutek can do everything the Dbox did, but if you don't have Ecutek do that, it frees up those cycles for other features. A sump also gives a better 'flow over time" measurement, which is ideal; your MAP adapter may net a similar result to a Dbox, but does it in an entirely different fashion!

Seems normal to me.

Jackson kits go 50k miles between changes.

I've had the Harrop now for 4 years, with no issues at all, and been very happy.
It still has a "wow" factor in terms of fit, finish and integration when people see it for the first time.
Currently running a Motec, but it was also fine with the Ecutek tweaked from Harrop.
Highly recommended from my point of view.

Harrop has the same interval. I believe Teslas has the same interval. I'm sure you could shorten the life of the oil by heat cycling the oil more and at higher temps, so if that is the case then you could change it more often.

I think a take away is that this isn't engine oil that has fuel and spent gases being mixed into it all the time. While it gets hot, it isn't coating the lining of cylinders that are under extreme heat from compression and combustion. This isn't thick gear oil that sees a lot of high pressures and operates against surfaces that aren't machined with the highest tolerances or finishes, and gear oil has a 60k interval. This isn't brake oil that has a 30k interval that is hygroscopic, meaning it absorbs moisture.

The Rotrex system on the JRSC uses a set of bearings operating in a planetary arrangement, and the RPMs get to 90,000 on these units, compared to 20,000 on the Eaton TVS 1320. There is a lot of contact area in the oil chamber, so for those reasons, the JRSC comes with an oil cooler for the supercharger, as well as, an oil filter and an oil reservoir, so it holds considerably more oil than the TVS units and requires more attention and considerations (see bottom image for diagram on the oiling system).

https://www.rotrex.com/wp-content/up...3957305607.png

https://www.youtube.com/watch?v=m9bx_Vtxm4g


Again, the Eaton TVS SCs have fine toothed spur gears that are isolated from the environment and have the resistance of the boost pressure and inertia of the lobs against the thrust of the drive belt/engine, so wear on the gear surfaces might be minimum.

Note: pictures are not of the Eation TVS 1320, but are used for demonstration.