Official Harrop TVS1740 Supercharger Thread

We've got two kits left for anyone that is interested. Thanks for the feedback everyone. The Harrop is definitely second to none!

BPMSport wrote

We've got two kits left for anyone that is interested. Thanks for the feedback everyone. The Harrop is definitely second to none!

You’re also a top notch guy Mike, anyone considering this supercharger should know it comes with unparalleled service and support from the vendor.

e90335e36m3 wrote

You’re also a top notch guy Mike, anyone considering this supercharger should know it comes with unparalleled service and support from the vendor.

+100

Mike was a pleasure to work with, and his tuning is superb - the finished product is imminently drivable under "normal" conditions, and then promptly turns into Mr. Hyde when you get on it. By comparison, the ESS tune felt rather inconsistent in part throttle situations, but I've felt nothing like that with the BPM tune I'm running now. Bravo, Mike!

What is the easiest way to access the bleeder screw on the harrop radiator? Is removing the front bumper the only way?

Second, to what level should the intercooler reservoir be filled when cold?

My harrop water pump is making some odd noises, and I've noticed the coolant in the reservoir today after a drive was somewhat frothy. I suspect I've got air in the system, and the noises are air bubbles passing through the pump.

Answering my own question for anybody who finds it later:

Removing the air duct in front of the radiator provides sufficient access to get a 10mm box end wrench down there to open the bleeder.

My hypothesis about my problem was correct, I had air trapped in the system. Pump sounds great now after a few rounds of bleeding.

I am still curious about my other question- What is the correct fill level for the intercooler reservoir?

The harrop manual gives no mention of how full the reservoir should be. In the past, I checked other harrop kit manuals and they specified to fill the reservoir to the neck. I had previously attempted that, and it resulted with dried up coolant splatters in various points around the engine after a drive. Seemed to indicate it was overfilled and coolant was expanding past the cap. A lower level helped.

I am now suspicious that the trapped air in my system may have had a cause in that. The air could be heating up and expanding causing the water in the system to expand past the filler cap.

drwankel wrote

I am still curious about my other question- What is the correct fill level for the intercooler reservoir?

The harrop manual gives no mention of how full the reservoir should be. In the past, I checked other harrop kit manuals and they specified to fill the reservoir to the neck. I had previously attempted that, and it resulted with dried up coolant splatters in various points around the engine after a drive. Seemed to indicate it was overfilled and coolant was expanding past the cap. A lower level helped.

I am now suspicious that the trapped air in my system may have had a cause in that. The air could be heating up and expanding causing the water in the system to expand past the filler cap.

Those fancy German hose clamps can come loose if they aren’t clicked down with the proper tool, if one comes loose on the suction side of the pump there’s risk of pulling in air. When I uninstalled my kit to move it to the sedan I discovered one hose fitting impacted this way. So something to check if it happens again.

I fill my reservoir so the coolant level is just at the bottom of the two inlet lines at the top of the reservoir. Would contact Mike directly with the question.

CamasM3e93 wrote

Those fancy German hose clamps can come loose if they aren’t clicked down with the proper tool, if one comes loose on the suction side of the pump there’s risk of pulling in air. When I uninstalled my kit to move it to the sedan I discovered one hose fitting impacted this way. So something to check if it happens again.

I fill my reservoir so the coolant level is just at the bottom of the two inlet lines at the top of the reservoir. Would contact Mike directly with the question.

One thing that always amazed me about the Harrop kit is the fact that the kit included 3 different types of clamps, and specified what clamp should be used at what connection point. They would have had to go out of their way to engineer and ship each kit this way, and part of me thinks there must be a reason they chose go that route. It would have been much easier for them to ship the kit with standard hose clamps for everything and they didn't.

Harrop does alot of OEM work from what I understand, and I suspect that expertise may have led to them being picky about certain types of clamps being used at certain locations. Over engineered maybe? Yes. I'm sure standard host clamps would work fine. In fact, if I needed a new clamp, I'd probably be using a standard clamp. But this is a German car, and over engineering is what German cars do. Having 3 separate clamp types almost fits the cars character despite the kit coming from Australia.

I called Mike today and asked him the fill level question question. He recommended setting the fill level when cold in the middle of the two return lines at the top of the reservoir. He specifically mentioned leaving room for expansion, which matches my thinking. I've tried filling to the filler neck like other Harrop kits suggest, but it results in overflow splatters when hot. I have had the fill level around the middle of the pipes before, and I don't recall any overflow then, but wasn't sure it was "right" at the time. I lost a good 2-3CM in reservoir fill level when bleeding the Harrop radiator yesterday. Might honestly be something worth checking some time after you've installed the kit.

Honestly, while thinking about this, it almost seems like a design that could be improved upon with the Harrop kit. It would be more ideal for the return lines to be completely submerged in the reservoir. For anybody who has built an open loop water cooled PC, think about how the return works in the reservoir. Submerged. You don't want air in the system. The principal of the cooling system is exactly the same here. Reservoir, electric pump, radiator, thing to cool.

To do this the Harrop intercooler bottle could be improved by lowering the return line bungs on the reservoir. This would allow for capacity for expansion, while keeping the return lines submerged.

Installed Harrop today. Car feels great. Also got RB's done, throttle actuator, idle control valve, fuel breather, do88 coolers and thermostat replaced. Thanks Mike at BPM for helping me get the kit and expediated too. Thanks ABRHouston for installing it.

Thank you. Got most of the other items done preventatively since the plenum was off. ABRHouston did the install, took almost a week. Just got the car yesterday, so not done the donuts yet 😀Will update soon.

7 years and 40k miles deep and loving every mile I drive on my Harrop M3. So nice that I kept the M3 when I got the 911 Turbo. Ohh that sound!! No problems at all to date. And you know Mike B will take care of you!

How smooth is everyone's idle here when your engine is massively heatsoaked and decently hot?

My idle is normally rock solid, but I've noticed that if I get things really hot and very heat soaked on a hot day, the idle will start bouncing a bit when at a stop. Its something I noticed last summer and as warmer weather is slowly ramping up, it something I have recently noticed again. This happens at any fuel level, but it usually occurs on a warm/hot day after I have been pushing the car hard, and then get stuck in really bad long unexpected traffic.

My initial thought is the Idle Air Control valve starting to let go. However, since the problem only seems to occur in very specific circumstances, it seems possible that this could be a quirk of the supercharger kit. If the idle air control valve was starting to go out, I would expect symptoms across other temperature ranges. It also seems plausible that the idle behavior could be caused by the idle air control valve starting to fail, and it will get worse over time and see effect in other temperature ranges.

In hindsight, I kind of wish I had refreshed the idle air control during the supercharger kit installation along with the starter, and some "lifetime" throttle actuators. All of those things will fail at some point. The fuel breather valve was changed during the supercharger install. Throttle actuators have already been replaced once, but they are OEM, and will die again at some point.

I will be adding a full Do88 kit at some point this year. Should massively help with the temps when its warm out.

The only issue I have with idle (definitely not related to the harrop kit) is if I press the brake when stopped at a light the idle dips to 500 or so and gets a little rough.

nycplumber wrote

The only issue I have with idle (definitely not related to the harrop kit) is if I press the brake when stopped at a light the idle dips to 500 or so and gets a little rough.

The exact same issue started when I developed a leak somewhere in the brake vacuum system. No luck after changing the pump and pressure sensor so now its onto the booster. Will report back after the booster install to see if it also fixes the low idle.

Mine had an occasional bouncing idle when really saturated with heat, both before installing the Harrop and when running the stock exhaust tune. I've since switched to a high-flow cat setup and got an updated tune from Mike, and I haven't observed the idle issues again since. No idea why that would make a difference, and for all I know, it may yet return.

Is there any trick to bleeding the intercooler? Mine has sounded like a lot of air is moving around ever since installation.

What tires is everyone running? Considering moving on from my Conti ECS and going to a 200tw tire.

nycplumber wrote

What tires is everyone running? Considering moving on from my Conti ECS and going to a 200tw tire.

I’m on conti ecs 265s. Width may be more important, looking to go to 295 30s in the rear for better traction off the line.

PS4S 295/30/19, still no traction with my setup but who needs it?

BPMSport wrote

PS4S 295/30/19, still no traction with my setup but who needs it?

Well crap. Thanks for chiming in, saved me $800.

CamasM3e93 wrote

Well crap. Thanks for chiming in, saved me $800.

295s absolutely helped with traction. Keep in mind Mike said the 295's don't hold his setup.

With the stock 265s, I could spin 1st, 2nd and 3rd. With the 295s, 1st still spins, but 2nd and 3rd hooks up.

Running PS4S 265/30/R19 Front, 295/30/R19 Rear.

I’m running 285/35/18 Hankook RS4 on the rear and they hook pretty damn good. I only run 200tw tires on it but the car also isn’t a daily. I think you notice a big difference going to a 200tw but be prepared for them not to last very long.

rodeo82 wrote

ABRHouston did the install.

Jesus, you spent a small fortune just on install etc… I’d hate to even ask what that bill was?

Nobody else running stock 18" wheels? 245/265 PS4S here. Wheelspin through 3rd but I find that fun when I'm not racing or trying to set a time.

BTW on the intercooler bleeding thing, I know that my shop who installed it knows what they're doing, but I guess I'm wondering whether the gurgling noise I hear when the pump is running with engine off is a sign of a problem or is just what it should sound like?