Is a larger Intercooler really needed?
 

My car is a 1981 930 euro model that is stock with the exception of the Fabspeed dual outlet muffler and Garrett GT35R Turbo that I just purchased from Chris at Turbokraft. Can't wait to have the new turbo installed!!

I'm already thinking about the next performance enhancement to my car and was thinking about either headers or a longneck intercooler. In my case, I have no plans or intentions of increasing the stock boost of .8 bar. Additionally, this car isn't used on the track and is a weekend cruiser only with short bursts of boost but not sustained high RPM/boost driving. I'm sure a more advanced intercooler will be beneficial, but is it really necessary in my case especially with a $2K price? Additionally, since I live in Texas the AC system is a Rennaire unit, but I drive the car in the mornings during the summer due to the heat. Provided below is a pic of my car and the color is factory paint to sample. Thanks for your input! http://forums.pelicanparts.com/uploa...1400791799.jpg

no benefit

Fabspeed claims a 40 whp increase with the use of theirs. Colder, denser air = mo' powa!

Let's see what others have to say about their experiences.

I have a GT35r and am in the process of installing a long neck garrettson intercooler. Ill let you know how it feels after. The car came with the GT35r and the oem intercooler and I wasnt comfortable with running the stock intercooler with that setup. Currently running .8 bar, but I do plan on turning that up to 1 bar with water methanol injection and the big IC. The car did run fine though and I have a dyno sheet from the previous owner making 348whp.

Nice 81! You have the muffler and GT35r turbo and are thinking of headers. I would think a bigger intercooler would be the next upgrade. You should notice a difference as your engine bay heats up in the Texas sun. I never had a chance to see the difference from stock to my Ruf as I did other mods at the same time. I'm sure someone on here has dynoed back to back. If you can afford it I dont think you would be disapointed.

Buy my used B&B from the classifieds. Less than half price of a new one.

Anytime you can keep the charged air , cooler... the better. The stock I/C sucks!!! You dont nessasarily need to go full bay, but get rid of that hunk of junk stock crap and get yourself a good used aftermarket one....

Well, considering how a larger aftermarket intercooler has a bigger cooling surface compared to the factory-installed intercooler, I think there is a significant difference.

Bottom line is larger cooling surface= greater efficiency

Along with what everyone has said about cooler denser air coming out of a bigger intercooler any after market intercooler with a thicker, wider, or longer core than the little stock one is going to be able to flow more air through it at wide open throttle while the turbo spools up. That's measured in cubic feet per minute or CFM.

With your stated use, and stock boost, I d say headers way before bigger IC.
CIS can't recognize the cooler air, doesn't add more fuel and it can't add timing... so I'm not sure where the power gains are. If you were blasting around the track and heat soaking your stock one, then yes a bigger one would differentiate itself and would be safer for you engine too. I just bought one and it's simply an insurance policy for track days for me. Any other benefit I'll believe when I see/feel it.

I'd optimize your exhaust with headers and dyno or wideband 02 to make sure you're fueling isn't too rich or lean anywhere including (especially) under boost.. You'll feel that every time.

Given where you live and the mods you are chasing you will need both.
Bolting a GT35 onto stock heat exchangers is really going to strangle that turbo.
Intercoolers are free horsepower, however that extra power does not materialize until the engine overtaxes the capabilities of the stock unit. That will occur when you get into heavy traffic and heat soak, or on a hot summer day, or when pulling boost for extended periods. It is simply not possible to accurately measure the effect of an intercooler on a dyno, the car must be running down the road with all the aerodynomics in play. Shrouding is essential.
If I were in your shoes I would add a larger intercooler now before summer and add headers this fall. Once the cold winter air hits you'll be looking for new rear tires next. :)

Your car looks beautiful. The color looks like the venetian blue that was only offered in '87 and '88 I think.

LOL
Yes the Sock IC' Suck and they Suck Air Well
and
For cars with no IC,
Stock IC compared to no IC
The Stock IC is a Perfect Upgrade in that scenario,

Added cooling benefits
plus
Small size so engine is clear to work on easily, which none of the Aftermarket have this design which is a flaw.

I would like to see a Cutaway of one of these $$$$ IC's

Stock was Designed by German engineers and scientists at the forefront of the days Technology

I bet they spent much more time designing their intercoolers than current aftermarket garage shop welders that sell them for thousands which still defeats me as to how they can ask that for a couple of sheets of stainless steel with a couple of pipes welded on.
Unles theres more to them than meets the eye?

Im sure Chris will show some facts, but i hope he or someone can show a cutaway and SHOW why they are better (Besides the larger surface Area) that part doesnt take rocket science

If they are as basic as i am led to believe i am buying a radiator core from a Holden Barina $129 on Ebay, and making one myself which will be just as efficent. if not more.

The B&B IC made a huge difference on my '83 930 in Houston.

They are fairly basic, but a radiator is going to be super restrictive.

It (a radiator) will definitely cool the air charge though, since the velocity will be severely slowed and many, many paths of small tubes to dissipate heat, but expect a huge delta of inlet to outlet airflow.

Go for it!

Good cores are not inexpensive. Our stock replacement intercooler uses the same design core as OEM Porsche did only taller. By the time you fixture and pay a few skilled US expert welders finish it up there is a fair investment involved. The DIY guy can do a one off for less as your time and skills are free, and you're not making 100 or 1000 of them which now involves overhead, insurance, sales people ...

^this^

!!!

you can find used ones all day, reasonably

you won't be disappointed

hmmmm

Say... wanna buy my short neck Garretson? I'm considering a full bay longneck 8-)

Get to the back of the line! SmileWavy

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/804437-b-b-930-intercooler.html

OMG Robby.
This is not new tech or info. Use the search or even google and you'll see that that post is ridiculous. There have been many comparisons on this subject. It's not even a question these days about the stock Intercooler. And harder to work on? O brother.
Dude do me a favor, when you weld up some stainless pipes onto an aluminum radiator of whatever type or whatever configuration you choose please don't take pictures of it and share. Not till you paint it some strange color anyway.

LOL.... I wasnt going to even argue with him.... He knows SO much.... :D