Rick Lee

So Friday I got my RS bypass tube and am looking forward to deleting about 15 lbs. and several cubic ft. of space in my engine room. But I'm a little worried about all the wires that surround the heater blower motor assembly.

Who here has DIY'ed this install and which wires do I need to worry about, where do I reroute them and can you hold my hand and wipe my nose too? Looks like this is a tad more involved that I had expected, though I'm still psyched to do it. Thanks.

Tom W

I did it on my 964 and it was a piece of cake. There is only one plug that isn't used that I just left open and will probably cover with electrical tape. I cut a slot for one sensor and drilled a hole with a slot for the other (a dremel works great for the slots).

I can take a picture once I get home (I'm off on vacation now).

I think the weight is more like a 5 lb loss, not 15 lbs. And be aware that the heat/defrost is SIGNIFICANTLY affected. Even out here where the weather is pretty good, the defroster sucks and heat is very limited. It's ok in a track car, but I would NOT do it for a daily driver.

Eric in Chicago

Rick,
I used a box and secured it to the engine fuse panel cover (looking at the rear of the car, on the left side of the fender) I put the coil it the box because I thought it might get too hot, it did not. The best reason for this mod, beside the cool factor, is the ablity to get to the top of the shocks in the rear as well as opening up the engine bay on that side for work on dist. cap, plugs ect. As my car was only driven on weekends in the summer and for 30 min. at a time, I cant address the heat/defrost issue but if Tom says its true, then I would expect loss of heat!

Rick Lee

Hmmm. Well, that's not real encouraging. I need my heat and heard that it only affects heat at idle. Previous owner had it in his 993 (track only and now going to headers, hence no bypass tube needed). This piece has no holes cut for accepting plugs or other connections, except for the dist. vent tube. PO said it made very little difference for his heat and he lives in my same area. I'm confused and am thinking hard about not doing this until I talk to some others at the track, who I'm sure have this mod. too.

Tom W

Rick, if you make the switch you no longer have a blower. Most the weight you hope to save is the blower/fan. The fan switch on the dash is basically useless after the change. It provides very little adjustment (from none to maybe 0.5 on the 0-4 scale of normal). Yes, it's worst at idle (next to non-existant) buts it's still pathetic while driving.

The couple times I've driven mine on the street on cool mornings, it took 15 minutes of driving to defrost completely.

Tom W

Spastic computer created duplicate post, please ignore.

Phil

I did this mod.
Defrost is ......well......gone! heat is OK......
I do believe, there is a way to override the NO DEFROst mode?

Rick Lee

Ok, one more question. I think I'm gonna do this, as warm weather is coming here and I'll probably be living in SoCal by the time cold weather returns to this area. Since you guys say the fan switch on the dash is useless after this mod, does that affect the a/c blower at all? Isn't the a/c blower operated by the same ****? Or does that **** control a different blower and keep my a/c fine? Thanks.

viperbob

A/C works fine. The rear engine blower just operates for heat...

JPS

How undoable is a heater bypass tube mod?

NP993

It's the reverse of the installation.

JPS

^^LOL... Well, is there electrical that was bypassed that needs to be unbypassed, etc., or is just sort of a bolt back in?

Thanks,

NP993

No, it's really very simple. Just remove the tube, put the stock stuff back on, plug in the electrics, done.