Official Harrop TVS1740 Supercharger Thread

[8500RPM]

Originally Posted by Bakerboy

Just out of curiosity does anyone run meth on there harrop setup?

I've never read about it. Harrop has a lot of unexplored territory left in it. I will say though some PD blowers have a coating on the rotors that wears off with meth. Not sure if that's an issue with the TVS unit Harrop uses.

[eternallx]

Could do some research over on the c7z06 and ZL1 forums too see if they inject anything. If they do then we should we able to as well since its the same blower.

[DukeofAlexandria]

Originally Posted by Bakerboy

Just out of curiosity does anyone run meth on there harrop setup?

I started to look into this/cad spec draw up meth injection holes on a regular S65 plenum but with a 1" velocity stacks. My ultimate goal was to inject into all 8 plenum ducts individually; mething directly at the front intake is ok, but you'll get a much better charge temp the lower down into the plenum you are. I even contacted Snow Performance about a setup kit like that and they can code basically whatever I wanted given they know the setup.

I spoke with Mike about this (probably 10+ pages back) and while he liked the idea, stated that the Harrop plenum leaves NO room for any type of velocity stack. I'd effectively have to either come up with a custom drill hole setup lower then what I'd prefer, some type of bigger hood (to add in the velocity stacks), or just mething at the intake near the front of the blower which...ok but not ideal.

I know guys who have meth/water injection on here, but I don't know/haven't' seen a Harrop kit setup like that yet. I know on centri-SC setups they do it all day long, but I don't think anyone has setup anything I'm referring to on an individual plenum duct setup.

-Duke

[BKrunner]

What type of supercharger in theory would put more strain on the Crank, cylinder one and the main bearings? Positive displacement or centrifugal?

[DukeofAlexandria]

Originally Posted by BKrunner

What type of supercharger in theory would put more strain on the Crank, cylinder one and the main bearings? Positive displacement or centrifugal?

That's a bit of a weird question to ask...but I suppose neither really if your blow-off/bypass valves are working correctly.

The cylinder and main bearings will be worn by excess load/compression; extra boost over top the intended amount from an SC setup will would have more wear and tear then normal.

Either one (SC/Centri) are just additive items on your motor that compress air into the cylinder, so really depends on multiple factors; boost levels, boost creep, duty cycle duration, rev limits, racing the car, etc.

Hence why it's a bit of a weird question hah, all depends on your application and the boost being the key factor, not necessarily the setup.

-Duke

[pbonsalb]

Probably the positive displacement since it should be in boost through more of the rpm range.

[8500RPM]

Originally Posted by DukeofAlexandria

That's a bit of a weird question to ask...but I suppose neither really if your blow-off/bypass valves are working correctly.

The cylinder and main bearings will be worn by excess load/compression; extra boost over top the intended amount from an SC setup will would have more wear and tear then normal.

Either one (SC/Centri) are just additive items on your motor that compress air into the cylinder, so really depends on multiple factors; boost levels, boost creep, duty cycle duration, rev limits, racing the car, etc.

Hence why it's a bit of a weird question hah, all depends on your application and the boost being the key factor, not necessarily the setup.

-Duke

The way he worded his questions points to the general belief that a centri supercharger on this motor tugs on the crank through the belt at a sideways angle. That in turn causes main bearing #1 to take extra abuse when supercharged with a centri.

From what I've read the PD blower like Harrop doesn't cause such strain on the 1st main bearing. I feel a PD blowers potential engine damage affects the rods themselves more than anything.

Centri blowers make peak torque much higher in the rev range than a PD blower. That means the rods take less abuse in the lower revs where they are most vulnerable. PD blowers make a lot of torque down low so that puts much more stress on the rods. S65 rods are prone to bending over the 400tq mark at the wheels.

[pbonsalb]

I am curious about the “sideways” pull of the centrifugal belt drive onto the crank pulley versus the “upright” pull of the positive displacement belt drive onto the crank pulley. Its a V8 so the crank has sideways forces on it already, but there is hopefully some balance from the opposing cylinder. I am not sure it’s any better to add stress to the crank pulley from above or to the side unless maybe the side unbalances the forces on the crank more. Otherwise it seems like it is a circle and there is not really a sideways on it.

The positive displacement is dragging hard from 2000 rpm through redline since it makes full boost over that range. The centrifugal starts a gradual boost curve around maybe 3000 and progressively builds to redline and makes full boost only briefly — at redline.

[BKrunner]

Originally Posted by 8500RPM

The way he worded his questions points to the general belief that a centri supercharger on this motor tugs on the crank through the belt at a sideways angle. That in turn causes main bearing #1 to take extra abuse when supercharged with a centri.

From what I've read the PD blower like Harrop doesn't cause such strain on the 1st main bearing. I feel a PD blowers potential engine damage affects the rods themselves more than anything.

Centri blowers make peak torque much higher in the rev range than a PD blower. That means the rods take less abuse in the lower revs where they are most vulnerable. PD blowers make a lot of torque down low so that puts much more stress on the rods. S65 rods are prone to bending over the 400tq mark at the wheels.

Thanks so much you clarified and explained what I was looking for.

[Scharbag]

Originally Posted by pbonsalb

I am curious about the "sideways" pull of the centrifugal belt drive onto the crank pulley versus the "upright" pull of the positive displacement belt drive onto the crank pulley. Its a V8 so the crank has sideways forces on it already, but there is hopefully some balance from the opposing cylinder. I am not sure it's any better to add stress to the crank pulley from above or to the side unless maybe the side unbalances the forces on the crank more. Otherwise it seems like it is a circle and there is not really a sideways on it.

The positive displacement is dragging hard from 2000 rpm through redline since it makes full boost over that range. The centrifugal starts a gradual boost curve around maybe 3000 and progressively builds to redline and makes full boost only briefly — at redline.

Turns out, I am dumb. Ignore me.

[pbonsalb]

As I understand, both harrop and all the centrifugal run off the accessory belt drive. I think the ESS VT650 replaces all pulleys in order to convert to 7 rib from factory 6 rib but is still in the same place.

[Scharbag]

Originally Posted by pbonsalb

As I understand, both harrop and all the centrifugal run off the accessory belt drive. I think the ESS VT650 replaces all pulleys in order to convert to 7 rib from factory 6 rib but is still in the same place.

I think you are correct. If that is the case, then why would any kit have different stress on the engine?

Inquiring minds would like to know.

Cheers,

[pbonsalb]

The Harrop is compressing air throughout more of the rpm range. It takes power to compress air. The centrifugal compresses air through much less of the rpm range and the compression gradually builds up. The Harrop might make 6 psi at 2000 rpm and keeps it up right through redline. The centrifugal makes no boost at 2000, makes maybe 2 psi at 4000 rpm and does not reach 6 psi until 8000 rpm.

There are now centrifugals with different gear drive mechanisms that are significantly improving the traditional centrifugal boost curve. ESS is developing one for the S65. Look forward to seeing some results as long as the price point remains well below that of the Harrop. The new stage 2 Harrop results look great to me — makes this old car very competitive with the newer performance cars.

[Properstyle]

Originally Posted by pbonsalb

The Harrop is compressing air throughout more of the rpm range. It takes power to compress air. The centrifugal compresses air through much less of the rpm range and the compression gradually builds up. The Harrop might make 6 psi at 2000 rpm and keeps it up right through redline. The centrifugal makes no boost at 2000, makes maybe 2 psi at 4000 rpm and does not reach 6 psi until 8000 rpm.

There are now centrifugals with different gear drive mechanisms that are significantly improving the traditional centrifugal boost curve. ESS is developing one for the S65. Look forward to seeing some results as long as the price point remains well below that of the Harrop. The new stage 2 Harrop results look great to me — makes this old car very competitive with the newer performance cars.

Amazing what changing a pulley does. I make over 9psi at 7800 lol in a Ess 625kit. If I want more I simply go to a smaller pulley again. I

[pbonsalb]

With your pulley that makes 9 psi at 7800, what does it make at 3900? 3 psi? A positive displacement blower that peaks at only 6 psi will be making that 6 psi well before 3900.

Sure, in racing where rpm are always over 5000 rpm in these cars, the positive displacement advantage is not as dramatic compared to a centrifugal that runs the same peak boost. In daily driving there is a huge difference.

I went down the centrifugal route with my E36M3, syartung with a 6 psi system, then an 11 psi, then 13 psi, then 16 psi. The version making peak boost of 16 psi at 7000 rpm redline made about 4 psi at 3500 rpm. I changed to a turbo and love the torque and power. Did not try a positive displacement on that car because few were made and they cost as much or more than a turbo system.

[nemesis_X]

Originally Posted by M.Hagen

From a %-gain standpoint, you are not out of the ordinary.

Your M3 made 30% more power compared to the full-bolt-on M3 that also has reference numbers on that same 'Mainline Dyno'. (393hp vs 303hp)

My M3 made 39% more power compared to my 100% stock M3, and I still have all factory cats and just a Megan rear section. (462hp vs 333hp)

If you make the assumption that full-bolt-on + tune is worth 9% over stock, then your power increase is in-line from others. If you take that 9% and subtract it from the 303, a stock M3 on that Mainline Dyno probably nets 277hp.

I do not think you have any operating or power problems, you are just using a brand of dyno that reads significantly lower than the standard Dynojet. If you want numbers for numbers sake, go find a Dynojet.

No didn't head onto the dyno to get numbers but rather to see if there was any issues post install.

Really appreciate everyone's contribution to my questions on the blower.

It drives great and i think that is all that matters.

[Bakerboy]

What plugs are people running?

I'm experiencing hesitation/misfire under load every so often.

Seem to be quite commonish for coils to cause this but wanted to be clear what plugs people are running before spending on a whole new set of coils.

I'm currently running stock plugs that I changed few thousand miles ago.

Thanks in advance

[Ashley_rj]

Recently got my e90 m3 s/c at the harrop factory in Melbourne. Very happy with the performance bump.

[eternallx]

Originally Posted by Bakerboy

What plugs are people running?

I'm experiencing hesitation/misfire under load every so often.

Seem to be quite commonish for coils to cause this but wanted to be clear what plugs people are running before spending on a whole new set of coils.

I'm currently running stock plugs that I changed few thousand miles ago.

Thanks in advance

Ah I had to shell out coilpacks money recently too because just doing the plugs didnt help.

[Bakerboy]

Originally Posted by eternallx

Ah I had to shell out coilpacks money recently too because just doing the plugs didnt help.

Was your symptoms odd loss of power when on full load at high rpm? Miss then power continues?

I have ordered a full set now after identifying cylinder 3 was problematic by running diagnostics and changed just the one.

Things have improved but still get it a bit. So I'm going to change them all.

[BPMSport]

Use stock plugs and if there are issues it must be the coils, injectors, or a fuel supply/delivery issue (barring anything cylinder specific/hardware). Ours pulls hard to redline hard with zero hiccups and Stage II.

[Icecreamfoo]

Originally Posted by BPMSport

Ours pulls hard to redline hard with zero hiccups and Stage II.

I can confirm this. After asking for like a month or two, I finally had the chance to ride in a stage II Harrop a couple nights ago. Tuned F10, AWD F90, those are all very, nutty fast cars, but the rush from this stage II, paired with the blower whine (which I personally love), is something else. There was no less than a dozen pulls, in 1st gear, in 2nd gear, in 3rd gear, and near top-end, the power just pours on in each and one of those repeated pulls. And as violent as the thrust was, the delivery felt surprisingly smooth (I dont know how else to describe it) from low end all the way up to redline with no signs of hesitation or hiccups... no wonder that other car ate a hellcat, as I'm still marveling at the experience days after. Hats off to all you stage II owners out there, I am truly envious