Stock IC vs built motor

[obrut]

Hi gang,

I’ve recently picked up a 79 930. Motor was rebuilt about 20000km ago with headers, K27 turbo, SC cams, dual out muffler - pretty standard old school 930 mods. However, the original intercooler was retained.

What effect do you think this would have on hp?

I’ve had hotted up 930’s previously but this car is a little hard to “seat of the pants” compare as it has also had a G50 swap.

[Matt at Pelican Parts]

Hi obrut,

With the list of modifications you've listed, just with headers and camshafts alone the engine is definitely going to flow much better. The stock intercooler should be able to handle the PSI but will be more restrictive for the modifications.

have you considered the RarlyL8 intercooler? It's one inch taller for more flow
https://www.pelicanparts.com/More_Info/RL930INTC.htm?pn=RL-930-INTC&bt=Y&fs=0&SVSVSI=812

or better yet there is a FabSpeed intercooler which is marketed for the K27 turbo
https://www.pelicanparts.com/More_Info/PELFSPOR911TICK27.htm?pn=PEL-FS-POR-911T-ICK27&bt=Y&fs=0&SVSVSI=812

[TurboKraft]

If you prefer a 3rd option, one that doesn't involve either the inefficient factory boost recirculation plenum or ugly red silicone hoses:

Longneck Intercooler
In stock
$2300 aluminum / $2500 satin black

[porsche 930twin]

My opinion is go with the Turbokraft option .. Chris knows his stuff flew over from Melbourne Australia to see Chris regarding my flat fan twin turbo build and gave me all the time in the world.. steered me in the right direction and offered parts that still work well several years on.. believe me the cheapest option will often bite you in the ass .. do it once do it right ... please share some pictures of your build... Cheers Paul

[5.7 GT1]

If I were looking to purchase an intercooler my first choice would be one of Chris's. No one has more experience with 930 aftermarket performance in today's world IMO.

[obrut]

Thanks for the replies, but my question has been missed in all the sales talk.

Will a motor like mine (making a bit more power than stock) be limited in power by a stock IC under regular street driving conditions?

[Alan L]

I am no guru, but for the conditions you state, I would not think a minor power loss would be of concern. Assuming there is one, and probably will be.
However - I look at it this way - engine preservation. The cooler you can run the charge air the better for your engine. As a consequence, intended or unintended, you get a performance gain. So it is a win/win. If the later IC is a better design (bound to be - no point otherwise), then you gain, as does your engine. Your wording suggests you are interested in more performance than trundling down to the supermarket.
I fitted a 964 IC - which Chris kindly suggested and supplied all fittings etc.
Alan

[mikedsilva]

Originally Posted by obrut

Thanks for the replies, but my question has been missed in all the sales talk.

Will a motor like mine (making a bit more power than stock) be limited in power by a stock IC under regular street driving conditions?

I wanna know where you keep finding these motors and cars???

[Ollies930]

As long as you do not try to turn up the boost past .8-.9 you will have no problems. Think of it this way, the original turbo was less efficient than the K27 at higher flow rates, consequently the charge air temp is probably lower than it was stock. The dual outlet muffler hopefully has less back pressure than the stocker and will simply allow more air flow and quicker response (at same psi will not change air temps a whole lot, depending on efficiency curve of K27 turbo). Same goes for SC cams, they will simply allow better cylinder filing and a bit better response, while at the same time reducing dynamic compression ratio. Overall you are not making massive sweeping changes to your engine compared to stock. As long as your A/F ratios are safe, you will be fine. If you decided on adding a better intercooler to this engine, the greatest difference realised is not in keeping the stock boost pressure, but in the fact that you can turn the boost up more.

[gassian]

I agree about the stock boost level and stock IC.
But getting rid of the recirc valve plus clutter in engine bay, i would say going with Chris TK IC is way to go

[Bucketlist]

^^^^^
And while your at it, why keep the stock air cleaner box. If you don't need to stay original go for the cone filter, that really opens up some space.

[tasturbo86]

No doubt the stock IC will limit HP when you start pushing it, but I doubt if you could tell any difference just tooling around on the street.
Mine is stock and I still have my license.

[Kraftday]

Originally Posted by obrut

Hi gang,

I’ve recently picked up a 79 930. Motor was rebuilt about 20000km ago with headers, K27 turbo, SC cams, dual out muffler - pretty standard old school 930 mods. However, the original intercooler was retained.

What effect do you think this would have on hp?

I’ve had hotted up 930’s previously but this car is a little hard to “seat of the pants” compare as it has also had a G50 swap.

The effect on power output = absolutely less power
Progressively variable I would estimate your down upto 50hp. Saftey and wear wise, you need a larger intercooler and oil cooler without a doubt. Just compare your question with Porsche's engineered components of the 965.

[TurboKraft]

Originally Posted by obrut

Thanks for the replies, but my question has been missed in all the sales talk.

Will a motor like mine (making a bit more power than stock) be limited in power by a stock IC under regular street driving conditions?

Simple answer: Yes.
It is quite limited with regards to total airflow through it (backpressure) and ability to dissipate BTUs. What's the exact limit? Hard to say -- it's usually one of the first items replaced, and here's why:

Typical 3.3L Turbo with a Euro muffler (no cat) and a K27 at stock boost.
Added a better intercooler: 24hp peak gain at the wheels and no losses anywhere 1500-redline, plus torque came in earlier. Those are gains from efficiency.

[obrut]

Originally Posted by TurboKraft

Simple answer: Yes.
It is quite limited with regards to total airflow through it (backpressure) and ability to dissipate BTUs. What's the exact limit? Hard to say -- it's usually one of the first items replaced, and here's why:

Typical 3.3L Turbo with a Euro muffler (no cat) and a K27 at stock boost.
Added a better intercooler: 24hp peak gain at the wheels and no losses anywhere 1500-redline, plus torque came in earlier. Those are gains from efficiency.

Thanks Chris, that was the info I was looking for. 👍

[obrut]

Here is the car in question. Full 80’s style…

[Manda Racing]

You don’t want to make too much power— you’ll just start breaking stuff.

[Alan L]

Originally Posted by obrut

Here is the car in question. Full 80’s style…

Wow - to quote an earlier poster - how do you find these things?
Alan