930 Intercooler Project

[Jim2]

Last year I posted an EFI conversion on my 930 and left off needing to add an intercooler. Over the winter I built the intercooler which is incorporated into a custom fiberglass tail. This ended up being a monumental amount of work (because I'm stubborn) included fiberglass and autobody work which is out of my scope, but I endeavored to teach myself with some pointers from an autobody friend.

The project is done with the exception of some very minor items. I spent the last few evenings (2:30AM), yesterday and today cleaning up wiring and plumbing so everything is finalized. The intercooler design is far from ordinary but it's based on some pressure and temperature tests I did with the original concept stemming from the early turbo RSRs. After three drives I'm seeing encouraging results.

Along with the intercooler I also added a larger throttle body and 72lb injectors. The 42lb injectors I originally used were maxed out at 6500rpm at 10 psi boost. Just finished driving it to revise the computer map and I notice my bottom boost threshold has changed from 10psi to 12. Perhaps the wastegate is too small now to hold it at 10psi?

Well, all I can say is, this thing has unreal power. It just keeps getting better.







EDIT - Here is a picture of the one of the factory race cars which inspired me to research this intercooler format.




EDIT - Pressure drop across the intercooler is about 1.75 psi. Temperatures are generally ambient plus 10F but at the very end of the straight on our track here I'm seeing ambient plus 40F. When I come into the pits, or after driving on the street the inlet ducting and intake manifolds are cold to the touch. There appears to be virtually no heat soak.


Here is a link to my thread with the efi conversion along with pictures of the intercooler construction.
930 EFI Conversion in process

Time for a beer or three.

[SCHNELE]

Amazing endeavor Jim, that I/C is massive. I don't see any sensors do you know what your temp and pressure values are?

[WydRyd]

Looks very similar to a Kremer/DP tail.

I admire your willingness to try something totally new

Well done!

[oms930]

Very good thinking! To echo the comments above, great to see out of the box thinking in finding solutions...

[Noah Holcomb]

That tail looks great on a slant nose car.

[turbobrat930]

I personally dont like the way the tail looks, but, its not mine and it was not ment to please me. I will give you HUGE props for thinking outside of the box, and fabbing it on your own. Very cool!!!! It'a allot harder to fab something up from scratch and actually have it perform...so GOOD JOB!!!!!

[Jim2]

Thanks for the comments guys. The temp probes etc are hidden in non visible areas of the plumbing.

Schnele, so far I've seen ambient plus 10* while on it, and ambient plus 20* at idle. I'll be on the track on wed so I'll get more thorough results then. I added a copule pressure taps so I can test pressure drop across the core and the TB. I'll start testing soon.

Merv and Olli, if you look close at 935 Kremer, DPs, and RSR turbos you'll see the rear of the IC core is not exposed on the rear, but ducted to the ground below the rear bumper where the pressure is lowest as the car is in motion. Mine is only a half assed attempt at the same.

Noah, I've bastardizd the hell out of this thing and I'm not exactly liking the looks but I've tried to respect appearance issues. Glad to hear you like it. Some appearance issues were, 964 tail lights for weight, rear reflector holes for airflow around the turbo when coming off the track, glass rear bumper for weight (still needs to be color matched), then, of course the intercooler. I located a used glass 930 replica tail in order to retain the stock appearance... somewhat. I wanted to leave the intercooler silver and spraypaint the porsche "turbo" scrip onto the cooling fins, but as I laid this out it look too boy racer, so flat black prevailed.

[NathanUK]

Looks great to me, very different.

[Craig 930 RS]

Block out the grill so you have meaningful air going through the intercooler via the engine fan.
Other than that, what a beast -

[Jim2]

Hey Craig, the air actually flows the other direction when the car is in forward motion, though no airflow when stopped, this is a trade off. While in motion it relies on positive pressure above the wing versus negative pressure behind the car which moves air rearwards through IC core. My objective with this format eliminates hot intercooler discharge air from going into the engine cooling fan, secondly, the cooling fan moves something in exscess of 10,000 CFM at full song and this open deck lid eliminates ALL engine cooling fan starvation from shrouding or I/C restrictivness. So far inlet charge temps have been far lower than what I saw with my half bay Garretson which was shrouded within 6" of the right side of the deck lid.

Doing a lapping session at the track tonight, should be fun with all the new bits.

Edit: Post track update - Unbelievable performance! Though three changes were made at once (intercooler, throttlebody, injectors) the collective difference is vastly improved performance compared to before. Far more top end power, and wicked throttle response, likely as a result of a cooler inlet charge temperature.

Couple road course laps, camera is a little shakey, breaks up a bit
http://www.youtube.com/watch?v=0NEH5di4Yds

[Craig 930 RS]

Very nice - sounds like you have done all pertinent research to make it truly work!
Way to go.

[Reaper930]

Okay so after 7 months to live with this setup - what can you tell us about how its holding up etc? All still rosy and good?

That's some great ingenuity and balls to do this setup...big thumbs up.

[slow&rusty]

Not sure how I missed this thread initially!

Gabe thanks for reviving it.

Jim - I really like the ingenuity of the placement and the design. And being that I designed my own top mount 3/4 bay intercooler (well I designed two different intercoolers, before I was happy with the final outcome), I cannot find any flaw with your design and placement for air flow.

I would have to say that it would be neat to see your car in the "flesh" to see the body work and tail modifications to make it all work or at least more high res pictures. Your pictures do not do justice, I am sure.

I am not sure I would taken the same route to do all the extensive body modifications, but probably because I am a ******* to mess with my cars lines, even though I am pretty good at working fiberglass.

One thing I wonder is why alot of people do not cut and rotate the Carrera intake to have the throttle body face the rear of the car instead of the stock placement where its facing up and forwards, just makes the intercooler piping \ plumbing a bit more tricky and longer. Just a thought.

Either way kudos for ingenuity and ballsy placement and a totally beautiful intercooler. I admit I love big big shiny intercoolers....there I said it...and yes I need help

Yasin

[Jim2]

Reaper, finished this back in 2007 been running good. The car got lots and lots of track time this last year even though I was going to retire it. I can't resist taking it out there! No changes since building it.

Yasin, I was going to rotate the barrell but I anticipated a sheet metal shroud segregating the intercooler from the cooling fan so I wanted the plumbing out of the way. Ended up not needing to change anything. The whole intercooler and surround can be removed in about 5 minutes. Three bolts, two hose clamps. Bolt the original tail onto the hinges and it's back to stock other than an intercooler. There were no permanent body mods, or holes drilled for that matter. I may change back to stock tail lights and center reflector though. I never really "got off" on the vent holes. I liked the light-weight 964 lights but they don't integrate appearance wise.

[RarlyL8]

I really like that Jim. You even get the great side effect of an easy access engine.

[juicersr]

Whoa, very cool setup! I always thought that the standard turbo tail was a compromise for the street for aesthetics and keeping water/ debris out of the engine, but really limited the amount of cooler air flow through the intercooler. I have toyed with the idea getting a basket case turbo lid and fabricating a rear 'flow through' vent for the turbo. It's based on a similar idea i had for the Carrera a while back, which i did just as a styling exercise to show off more details of the motor.




Had it mounted on the back for a while before switching to a ducktail. Never had any problems.

Would a small vent at the back of the turbo tail allow better air flow over the intercooler without compromising dirt/ debris entering engine too much? Dont really drive the turbo too much in rain anyway.

[Miguel Antonett]

Somehow I missed the initial post, but that arrangement is as practical as it gets allowing natural air flow through that massive interlooler. Not much benefit while standing still - but who cares?

+++ on the engine access........... Good thinking!

[juicersr]

Miguel, happy new years friend!

I was thinking that cutting a flow-through vent in the rear of a 930 lid similar to this Gemballa lid would be very effective for increasing flow accross the intercooler. Plus, if you had some cool shiny, blingy bits in the engine bay, would be nice to be able to show them off a little too.

[Miguel Antonett]

Happy New Years to you...

Agree. That's a cool and effective lid on a bad azz looking machine. Gemballa is a master of creativity and proportionality.

[Jim2]

All that Gemballa stuff just looks nutz. They take the prize at making aggresive looking cars.