CR Gen2 blower issues

[evan9eleven]

Hey everyone,

Tried searching, and emailing Classic Retrofit almost two weeks ago, and tried posting on their forum last week. Lacking a response I thought I'd post here.

I installed a Gen 2 blower in my SC and have some issues that I'm unsure how to best get resolved.

The first issue is air leakage. At speed, there is audible wind noise in the cabin along with air escaping from various parts of the dash. Pulling out the clock while driving quickly exposes quite a rush of air from the front baggage area.

I am confident that I have a good hood seal, the hood shuts tightly and there is no water ingress. Hood seal is new. The blower is installed as instructed with no gasket; though the OEM blower had one. The fit is good and relatively tight where it mates to the fresh air inlet. All unused ports on the blower are blocked off. There is no other opening where air could be forced into the frunk at speed.

As a test I blocked off the entire fresh air inlet and went for a drive. The amount of air inrush was reduced but not eliminated.

The second issue I have is with water and drainage. When washing the car or driving in the rain, any water that enters the fresh air inlet immediately leaks out of the bottom of the blower housing and into the frunk and smuggler's box. I have both drains connected but the water exits elsewhere and not from the drains at all. Water also runs out of the blend valve outlets and on to the floor of the car.

A bit frustrating for sure, anyone have input for me on this?

[Showdown]

Originally Posted by evan9eleven

Hey everyone,

Tried searching, and emailing Classic Retrofit almost two weeks ago, and tried posting on their forum last week. Lacking a response I thought I'd post here.

A bit frustrating for sure

Yup...


I had similar issues with the Gen 1 blower and found the only solution was to fully block off the fresh air inlet and to drill the drain holes larger and fully seal the blower end covers as the provided gasket is worthless. None of those should be considered adequate solutions to a problem that shouldn't exist.

My feeling was that I purchased a very expensive DIY kit and not a ready-for-primetime product.

I also had massive trouble with customer service, but I digress.

[evan9eleven]

Julian, I assume that sealing off the end covers required fully dismantling the blower. Which gasket are you referring to?

With regard to blocking off the fresh air inlet completely, did this solve both air leakage and water ingress issues for you? Did you consider another solution for fresh air to the blower or was this not relevant for your needs?

[Showdown]

The gen 1 blower had plastic ends where the hoses connected to. There was a foam gasket that was between the metal body and the plastic ends... it was worthless. I replaced it with a thicker one and then used 2" wide electrical tape to actually seal the interface between the body and the end caps. It's done fine so far but who knows on the longevity.

As far as the gasket blocking the fresh air intake- that's blocked enough water that I don't get any leakage in the trunk but again, I drilled my drain holes to be larger so to accommodate a higher flow of water as I anticipated this being a problem. But unfortunately it's blocked the fresh air as well and that I need to rectify.

I've been pretty disappointed with the CR system since turning it on and receiving a mediocre flow of air. The temperature isn't the problem- it gets plenty cold, which ironically is because the compressor, condenser, drier and plumbing are all stock components available from any number of aftermarket HVAC companies- CR didn't design or invent any of those parts and they work as they should. The problem for me was in the CR designed blower housing and the restrictive Porsche ducting/valves.

I've disassembled my system and created my own valves and digital servo controls for them so that they actually allow airflow.

I'm in the process of designing a second gen version with better valves and a fresh air valve so that I can have fresh air when open and no water ingress (or hot air) when closed. Gen 2 also passes the heat through the blower and new ducting so that the system operates like a modern HVAC system with zones.

I suspect that eventually I'll just throw away the CR blower and housing and salvage the core components and just design my own. I'm reaching the end of tolerating having to hack things that were supposed to be plug and play and very expensive.

With 3D printing, online CNC, and the global marketplace it's never been easier to design and build our own stuff without the lousy customer service, questionable fit and finish and hefty price tag that so many aftermarket parts producers levy on us.

/rant

[Jonny H]

Originally Posted by evan9eleven

Hey everyone,

Tried searching, and emailing Classic Retrofit almost two weeks ago, and tried posting on their forum last week. Lacking a response I thought I'd post here.

I installed a Gen 2 blower in my SC and have some issues that I'm unsure how to best get resolved.

The first issue is air leakage. At speed, there is audible wind noise in the cabin along with air escaping from various parts of the dash. Pulling out the clock while driving quickly exposes quite a rush of air from the front baggage area.

I am confident that I have a good hood seal, the hood shuts tightly and there is no water ingress. Hood seal is new. The blower is installed as instructed with no gasket; though the OEM blower had one. The fit is good and relatively tight where it mates to the fresh air inlet. All unused ports on the blower are blocked off. There is no other opening where air could be forced into the frunk at speed.


As a test I blocked off the entire fresh air inlet and went for a drive. The amount of air inrush was reduced but not eliminated.

The second issue I have is with water and drainage. When washing the car or driving in the rain, any water that enters the fresh air inlet immediately leaks out of the bottom of the blower housing and into the frunk and smuggler's box. I have both drains connected but the water exits elsewhere and not from the drains at all. Water also runs out of the blend valve outlets and on to the floor of the car.

A bit frustrating for sure, anyone have input for me on this?

1. Air getting into the frunk happens on all air cooled 911s. They all do it - even with a good hood seal. Nothing to do with our blower. Ask anyone with a stock 911 what happens when they take a gauge out and you'll get the same answer - a rush of air. I can think of no other vehicles that have rubber seals on their gauges - that's a bit of a clue that Porsche knew about this.

2. Evaporator water is caught by a tray inside the blower and fed to the drain tubes. Rain water entering the hood inlet can get by the foam seals on the end caps if they have become dislodged or disturbed during installation.. The metal panels that make up the body of the blower are held with screws in sliding slots that allow the panels to be adjusted to meet with the foam seal. You can loosen these and readjust. You want the sealing to happen at the bottom since that is where the water is. There can be air leakage around the cap for the same reason but it is small and does not noticeably affect air flow at the vent. You can run some sealant round if it bothers you.

[evan9eleven]

Thanks for the responses everyone.

Funny, I don't remember any such frunk air leakage with the OEM blower. I'll have to look into possibilities to seal it better, as it will be pretty unpleasant with all that air getting in on chilly days.

I'm also in the camp that thinks I should have been able to expect the drains on this unit to work, that water wouldn't end up in the cabin, and that the end caps wouldn't leak. Are the gaskets so flimsy that they won't stay in place? Its not like I kicked the blower around the shop before installing it.

A bit disappointing. Looks like I'll be pulling out the unit for some sealing and retrofitting this winter.


Julian, I saw your thread regarding your homemade solutions. Cool stuff.

[Duc Hunter]

I’m not sure what kind of climate you’re in, but my Classic Retrofit air-conditioning system drips a lot of water to get the humidity out of the cabin here in Florida. There’s a hole on either side of my GEN one blower in the bottom that are the drains and I have 90° plastic fittings that I put in there through a Gromit, they connect to a clear piece of hose and come together in a Y and then drain out through the hose that goes out the bottom of the smugglers box. It literally is pouring water out under the car because of our humidity here. If you did not hook up the drains to a hose and route that hose out somewhere that would be why you have water in the front. The other reason I get water dripping on the paint inside the trunk is because The blower, and many of the hose is sweat moisture like a coat. Can you just took out of the freezer. That’s a problem again here in Florida because the blower box and those hoses get so cold with the cold air flow flowing through them, that they condense the moisture in the trunk onto them and then it dripped onto the body. That’s just from the outside so if you live in a humid climate, you could see that.

As for air blowing in, I fought that significantly in my car. As Jonny says they all get some in the front. I just did a 15 month partial restoration on my car and the number of holes and openings we found to the outside of the car inside the trunk was phenomenal. The steering column area is a huge one, cause it’s supposed to have a big piece of foam around it to try and seal it off, which most of that foam is now rotted out decades ago in our cars. And it’s the same thing for me if I pop my clock out, or if I pop out my seatbelt light, I get a massive rush of air. That rush of air has absolutely nothing to do with the Blower. The easy test for that would be turn the blower off and see if you still get a massive air rush in from the trunk. Keep in mind to the vent over the rear window in these cars means that there’s always a bit of suction out that, which will pull air in from anywhere else.

As for your outside air inlet, here in Florida, the air is so humid that I chose to block mine off from day one. During my restoration, I actually made a custom metal plate that covers it outside, so there’s no vent at all. As we keep talking about in the trunk, these cars are leaking enough and let enough fresh air in anyway that you don’t need that. Plus in the winter, not having it makes the car warmer.

[Jonny H]

Originally Posted by Showdown

The temperature isn't the problem- it gets plenty cold, which ironically is because the compressor, condenser, drier and plumbing are all stock components available from any number of aftermarket HVAC companies- CR didn't design or invent any of those parts and they work as they should. The problem for me was in the CR designed blower housing and the restrictive Porsche ducting/valves.

Ouch.

Yeah all easy peasy with hindsight but this project started 11 years ago. From nothing.

Back in 2014, there was only one 12V compressor on the market. A few folks had tried to make systems with it but they did not work. The main issue was the fixed speed needing a constant 100A to get decent cooling. Not a workable solution. Using a mechanical mindset, AC guys tried to build systems that 'cycled' like a belt driven system. They didn't work and they concluded it could never work.

Anyhow, I was an earlier adopter of domestic heat pumps and studied the NIBE system installed in my self build house. I realised that the key to making scroll compressors perform is the control of the compressor speed.

We commissioned a variable speed version from the manufacturer and developed the PID based power control strategy which runs in our ECU. That is the sole reason why our system works. Without it, you can either choose to be cool OR to have healthy battery voltage BUT NOT BOTH. Buyer beware - most compressors sold by aftermarket AC companies to this day are fixed speed.

Since then we have changed compressor supplier and now work closely with them to improve both our product and theirs. We even helped them redesign their internal PCB.

Plumbing... No aftermarket AC company had ever heard of pad fittings - they all used threaded. So the pad fittings you have in the kit had to be designed and machined in quantity. Try persuading a fitting manufacturer to make 100 sets of fittings. They laugh at you unless you want 10,000. So we machined them all ourselves. Now you can buy them.

Hoses... 10 years ago everybody thought I was mad using Oetiker clips - how can a hose crimped with a hand tool withstand 250 PSI? Commonplace now though.

Not to mention that during this period between WOSP and ourselves, we developed the 175A alternator. This took the best part of 2 years and many failed attempts to get right. Now they are on Pelican.

So since we started this thing, aftermarket parts vendors are now selling similar items. Thing is, they do not know what they are selling or how to support the parts. Two years ago we helped fault find a system that was completely mis-sold to a company making $1M Ferrari replicas. The electric system sold to them was over £6000 and had no support. The parts were mis-matched and the compressor was less than 1/4 the output needed. The company that are mis-selling these parts are a household name and the biggest aftermarket HVAC supplier in Europe - no joke.

In 10 years the aftermarket has now got most of the parts that we pioneered the use of. That's ok because we are about to leave them all behind again with heat pumps and custom hard lines...

We never 'invented' the parts but we went through a long process to build an effective and usable system that we stand by and support.

---

It is not the compressor or the 'standard components' that makes it cold, it's the system design as a whole. Like any engineering, there are compromises and balance. E.g. if you have increased air flow, the air wont be as cold - basic heat exchanger thermodynamics. Bigger fans do not necessarily mean more air - depends on pressure drops and duct sizes.

Anyone could potentially roll their own blower unit and your requirements may differ.

Ours is designed to:

1) fit all cars from 1969 to 1989 ( it also fits earlier cars with some mods)
2) fit LHD and RHD cars which have different firewall, duct routing and dash layout.
3) fit cars with and without brake boosters ( which swap sides depending on L/RHD )
4) connect to the existing blend valves and ductwork.
5) work with the existing electrical and bowden cable system.
6) be compact so as not to interfere wit the smuggler's box lid (which is different for RHD and LHD)
7) look attractive and 'OEM'
8) not be too noisy.
9) recirculate the air from the cabin.

Maybe you are ok having a gigantic ugly fan sticking into your luggage bay but this isn't going to cut it for most people. The resultant 'gains' are most likely lots of wind and noise and not much cooling. Also be careful you don't blow the evaporator water through the ducts and straight at the occupants.

Oh, and make sure you can close the hood!

[Glenfield]

Thanks for supporting the hobby Jonny and continuing to move it fwd. That’s a lot of constraints to reconcile and I think you’ve done an excellent job with the product, the supporting literature and your engagement on these boards.

It’s a very big small company you’re running.

[Duc Hunter]

I look forward to the soon to be released, and over engineered, market leading Showdown A/C systems.

As for air coming in through the Frunk, I just installed a new trunk gasket, and plugged the last of the holes in my trunk after a 15 month restoration with lots of metal work. Today on the freeway in a very hot and humid Florida day, once the cabin was cooled off, I pulled my clock out of the dashboard. There’s almost no air coming through from the trunk into the cabin now. And the length to which I have gone to replace every Gromit, rubber gasket, seal, etc. has been extensive. My 3.2 Carrera on the other hand is all factory and unmolested upfront in terms of its gaskets and grommets, and it has air coming from the trunk into the cabin.

As for the Classic Retrofit generation, one blower, I don’t understand what all the complaints are. Mine works great and has since day one. There are a few refinements that could be made. Yes, but I have one of the first blowers supplied to a customer and it’s working like a champ. My biggest issue is it often looks like a sweaty frozen Pepsi can driving around because of how much moisture it’s Condensing on the outside of it from my humid air.

[evan9eleven]

Hi everyone,

First, thanks for all the feedback and information.

Second, Jonny, I appreciate that you guys have put a lot of time into developing these systems, and I will continue to support your company. At the same time, I hope you will be open to some constructive criticism from your customers, within reason, as this is a path to improvement. I'm going to offer some below.

Third, you guys were all correct about leakage of air into the frunk, the area around the steering rack is a huge air intake. I plugged the unused smuggler's box ventilation plumbing under the blower, and sealed the area where the steering rod enters the smuggler's box. Guess what... no more frunk air leakage. SOLVED!

And finally... let's talk about the shortcomings of the blower with regard to being watertight, and draining properly. Several have commented about drainage from the evaporator. Well, that's all fine and dandy, but I'm not running AC. Where I live it rains. Often.

I took my blower apart this past weekend, and learned that the drains on this unit appear to be solely made for evaporator drainage. They mate up to the evaporator drip tray with a couple rubber washers. It appears that CR didn't take into consideration that water was going to get into the unit in quantity through the fresh air inlet, as there is no real provision for draining the blower housing itself. Amazing, considering that the OEM blower essentially had a big funnel at its base, where water could just run straight into the drain and out under the car.

Which brings us to the foam gaskets on the housing ends. Julian is absolutely right, these are completely worthless. So any water getting into the unit and ending up in the base of the housing just runs out into the frunk. Sorry, but this is just not acceptable. The entire base of the unit should have had a provision for proper and complete drainage, with the rest sealed up. (Suggestion for Gen 3...)

My solution, though really crude and kludgy, was to 1) add an extra drain hole at the bottom of the unit, 2) attach a c-shaped piece of PVC pipe to the bottom to catch water, 3) add a drain tube to this contraption, and 4) seal up every seam on the whole thing with silicone. The little drain tube has a 90 degree elbow that then goes into the factory drain.

I admit that this is damn ugly, but no one will see it. Most importantly: I re-installed the blower and dumped a glass of water in the fresh air inlet. Lo and behold... the water drained right out of the tube intended for the purpose, under the car and onto the ground. Not a drop in the frunk. Hooray!



ustom




.

[Showdown]

Clever solution, glad to see it was simple and effective!! Onward!!


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[Duc Hunter]

I just thought I would update everybody on a discovery. I made regarding rainwater getting into the trunk. As I mentioned above my car, just did a 15 month restoration, including repair to the Cowell. There are three other 911s in the shop all going through some level of metal work. What we discovered regarding the top edge of the trunk seal to the Cowell below the windshield was kind of shocking. On every one of these cars the trunk seal fails the dollar bill test. That is you take a dollar bill put it between the gasket and the trunk from the towel, close the trunk lid, fully, and try and slide the dollar left to right across the car or pull it out. If your seal is making proper contact, you will meet a fair bit of resistance and trying to move the dollar bill around. On my car, the dollar bill moves freely from the passenger side, wiper arm extension almost all the way over to the driver side corner. What this means is That as rainwater washes off the windshield and down the Cowell, it will go right over the back of the gasket and some of it will come into the trunk. My very experienced body man, and I have decided the best way to solve this problem is to put a piece of rubber on the underside of the trunk where the gasket meets the trunk to close the gap. This may not cause air rushing in like was described above, but would certainly cause water to be coming into the trunk. It certainly does in my case. The restoration shop I’m working with was surprised, check the other two cars they had in there and all three of them have the same problem. They even spent a lot of time on mine and the other two cars dolly in that area up to be better and make more contact, to no effect.

[evan9eleven]

Great tip, Duc.

I didn't have a buck handy, you know, being in Norway and all. But an invoice from my Porsche parts center on regular printer paper worked fine. I get good resistence pulling the sheet of paper out. And in any event, the water I was experiencing in the frunk was clearly leaking out of the blower seams.

[Jonny H]

@evan9eleven. We are constantly improving the product and the internals are different now.

What is interesting is that you are using the blower without A/C so I am guessing this means you did not fit the gasket behind the hood mesh? The gasket is there to limit outside air but of course it limits rain entry too.

Without the gasket, the amount of water coming in would be 3 times more than expected. which goes someway to explain your troubles.

[evan9eleven]

Originally Posted by Jonny H

@evan9eleven. We are constantly improving the product and the internals are different now.

That sounds encouraging Jonny, please tell us more.

Originally Posted by Jonny H

What is interesting is that you are using the blower without A/C so I am guessing this means you did not fit the gasket behind the hood mesh? The gasket is there to limit outside air but of course it limits rain entry too.

Without the gasket, the amount of water coming in would be 3 times more than expected. which goes someway to explain your troubles.

Correct, I am not using the gasket. Of course that will limit, but not eliminate water ingress. However, the issues I've pointed out above regarding sealing of the unit and better drainage are just as valid-- it isn't that the water is getting in. The issue is what happens to that water once it enters the blower, and I'm right to expect that it will exit through a proper drain.

I'll install the gasket in any case.

[Showdown]

I had the gasket installed and there was no noticeable effect on water ingress during rain. The hood vent/opening scoops in a massive amount of air and does the same with water.

I eventually blocked the hood vent completely and am now designing a servo controlled valve to open and close for fresh air.

I’d suggest larger drainage holes, larger drain hoses, hose nippes that are not merely glued on to the exterior (mine broke off in shipping) and a pitched housing so that the water actively drains.


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