Just a Random Thought: Turbo without a whale tail

82SC · 12-07-2002, 03:02 AM

is there a way to use an OEM 930 or 993 turbo engine but install a modified intercooler so one can use a regular decklid??

I know they use the whale tail to accomodate the intercooler, but I've always like the really clean lines of a non-tailed 911

just wondering if anyone has modified the intercooler or used an aftermarket one that fits...

MJ

beepbeep · 12-07-2002, 03:34 AM

Quote:

I know they use the whale tail to accomodate the intercooler

Wrong, they use it to lower rear-wheel lift @ high speeds.

82SC · 12-07-2002, 06:04 AM

but is that its main purpose?
I thought it was to accomodate the IC...obviously reducing lift is also it's function.

beepbeep · 12-07-2002, 06:17 AM

Early 75'-77' 930 don't have intercooler at all, but do have whale-tail.

masraum · 12-07-2002, 06:24 AM

On the cars that came with intercoolers I think the tail's primary purpose is to allow room for the intercooler, the reduction of lift is secondary, but probably not by much.

beepbeep · 12-07-2002, 06:53 AM

Quote:

reduction of lift is secondary, but probably not by much.

look at the diagrams i posted and decide yourself if it's much or not...

Doug E · 12-07-2002, 07:05 AM

Interesting graphs.

Guess for everyday driving it doesn't make much of a difference but on the track at higher speeds I'd want to make sure I had a tail behind me.

masraum · 12-07-2002, 07:32 AM

I've seen the graphs, read what I said again.
Reduction of lift is secondary (to making room for an intercooler) but probably not by much.

In other words when they added an intercooler, making room for it was more important that reducing lift, but reducing lift was almost/very close to being as important to making room for the intercooler.

I did not say.

Reduction of lift is not much.

I have read the books, and know the benefits of lift reduction front and rear and the fact that a car with a front spoiler will actually increase rear lift and vica versa. If lift reduction was the primary reason, then all 911's would probably have tails since the top speeds aren't that much different through many of the years.

Just wanted to clear up any misunderstanding.

Emission · Emission's Garage

I think Masraum is trying to say that the difference in top end between a Carrera and 930 could be less than 15 mph (145 vs. 160).

If high speed stability was the #1 issue, all cars would have tails (note a non-tailed car has quite a bit of lift at 145!).

Porsche found, as an added benefit of intercooler packaging, the tail proved much improved lift reduction. However, the rear tail now required a larger front spoiler.

You can locate the intercooler anywhere you want on the car that allows cooling. Remember, when you go on boost, you are pressurizing all of the air in that system. If your 'path' is more than a few feet long, you will have serious lag (you don't want the intercooler in the front grill).

dean · 12-07-2002, 09:39 AM

Sure you can run with out a tail. You could use an air/water intercooler, very costly. You could put the intercooler in the wheelwell. You could take the intercooler off and run lower boost. You could put a 3.6 N/A in. The only good choice would be the air to water intercooler. And it would be hard to get the exchanger under the decklid.

Jack Olsen · 12-07-2002, 09:41 AM

I've seen custom intercooler setups made to fit under a ducktail, and I've thought about using the additional space afforded by the rear flares for one. There's also the water-to-air-type option, which can be put in the rear seat area.

Any way you slice it, unfortunately, it gets pretty darned expensive.

twin plugged targa · twin plugged targa's Garage

interesting topic!- Jack, your old car had more tails than a school of fish!!

How many did you end up with? 4?
Correct me if I am wrong but did'nt the first non IC turbos have a tail more similar to the carrera tail and it was when they put the IC in that they produced the tea tray spoiler!
Infact I think they called it the Turbo Carrera?
As for relocating the IC what about ducting from under the car? (out of sight)
Just a thought!
rgds Ben

krk · 12-07-2002, 01:00 PM

Quote:

Originally posted by twin plugged targa
interesting topic!- Jack, your old car had more tails than a school of fish!! How many did you end up with? 4?
Correct me if I am wrong but did'nt the first non IC turbos have a tail more similar to the carrera tail and it was when they put the IC in that they produced the tea tray spoiler!
Infact I think they called it the Turbo Carrera?

In '76, the script under the tail does indeed say turboCarrera, and your description of the shape is I think correct. In stock form, there is airconditioning gear in the tail. The air pulled into the engine compartment flows through it. (air conditioning and no cupholders)

Hm. Anyone seen an intercooler solution for an early car that maintains the early tail?

hth.

krk.

masraum · 12-07-2002, 02:23 PM

It seems I have seen here or read about a very small intercooler that fit in and older non "turbo/tea tray" style tail, but the IC was very small if I am remembering correctly.

82SC · 03:12 PM

i was justing thinking with all of these 3.6L conversions...I think soon when the 993TT's get older and older there may be a small rise in transplants of a 993tt motor...and how cool it would be to hve a REAL sleeper...early car with coilovers and a tt in the back...

and if you could keep the stock decklid or a ducktail no one would be wiser...

I'd be interested in seeing a setup that JO mentioned about fitting under the ducktail

also I know next to nothing about turbos...

what is the differnce between the OEM and the water/air one that the above posts mention?

and what exactly does the intercooler do? does it cool the air that is forced into the CC?? I know the general principle that you use the exhaust gas to spinng a turbine which forces the air into the CC...

and with these air/water IC's do you then need a water pump to circulate the water? and does that end up needing a radiator??

Also I was imagining keeping the IC in the stock position...but instead making slanted at the edge that juts out...I know you'd lose a little surface area...but would the loss
be detrimental to the IC's function? (so it's side profile is not rectangular but is a trapezoid)

MJ

tsuter · 12-07-2002, 03:13 PM

When I put a Turbocharger on my 78 911SC I elected not to put in an intercooler because of space, cost and efficiency. Running compressed air through a big box is not efficient.
I solved the potential detonation by adding a microfueler aka Callaway Microfueler. This allows you to richen up the mixture when you are on the boost. It is essentially a supplemental fuel system that is switched by pressure in the turbo discharge pipe. I run about 9-11 lbs with it and have no problems and no need for the intercooler.

nhurto · 12-07-2002, 03:24 PM

Any idea what effect the c2/c4 style flip-up wings have on lift? I've heard conflicting opinions as to whether or not they reduce lift or merely direct more air over the engine for better cooling.