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Put together my 991.1 together over the last year or two. Goal here was to make the ultimate naturally aspirated carrera. Drivable on the street and long road trips while being able to embarrass GT3s on the track.
Started off as a 2015 991.1 GTS PDK.
Engine:
Deman Motorsports 4.5L conversion. Dyno run incoming soon! Should be around 540hp at the wheels.
Suspension:
DSC v3 controller
Full tractive DDA suspension
TPC racing sway bars, links, front axle width kit
Exterior:
DB Carbon GT mirrors
DB carbon wing triangles
OEM 911 R rear grille
Safety:
Custom installed AL Priority laser jammers by Musicar Northwest
Hardwired Uniden R7
Interior:
991.2 steering wheel + DB carbon trim
JoyeAuto carplay retrofit
Custom Stage 3 audio system (Morel speakers + Mosconi amp) by Musicar Northwest
Car is a beast to drive. Faster than my friend's 991.1 GT3RS and the ride quality is lovely while on the street but the suspension is insanely grippy while driving hard. Sounds like a cup car with valves open at WOT too
Very cool! Love the rear grill cover! I was thinking of sending mine (2013 S) out to RR Racing for the supercharger.
Originally Posted by thesaintusa
Either a Deman 4.5 conversion or the RR supercharger would both be on my list of things to do with a 991.1.
Enjoy and keep posting your thoughts/review.
I did a ton of research before going with Deman for the 4.5 and also considered just going for a 991.2 GT3 as an alternative too. Obviously the 991.2 GT3 would hold value much better but ultimately I was never a fan of the wing and would want to do exhaust, suspension, etc. anyways. I'm VERY happy with the final product and I've had plenty of seat time in .1 and .2 GT3(rs)'. It's refined-- it doesn't feel like a "modded car".
The biggest issue for me with the RR racing route is heat. These are naturally aspirated cars and even though it's a closed deck design you're generating way more heat with a supercharger. They have an ingenious design to deal with not putting tons of stress on the belt, etc. but the heat is still an issue. And even though you don't run a ton of boost you're still probably going to run high rpms at the track so that means extended use at heat and max boost. They, for example, recommend an extra oil cooler system for track use. It's also going to be a much harder sell to sell a car w/ a supercharger vs. a deman build from what I've seen (they obviously won't get what they put in but do sell for a noticeable premium).
The other engine builders one could consider would be Jake Raby, BGB motorsports, and Deman Motorsports. Jake Raby was booked out over a year and frankly I couldn't get any kind of dyno charts or info about his builds nor was there a decent number of these conversions I could find info on.
BGB motorsports seems to have done a fair number of conversions. Their conversion is 4.2L and they've done a fair number now. That said, after talking to BGB and rick the deman package just appears to have gone through quite a few more iterations and is a very polished product at this point. I've only heard of one failure on the 4.5L owner's thread (bores scored from tracking it right after breakin) and every other engine has been super reliable. I had to send mine back once but ultimately it turned out my old injectors were slightly clogged (causing a bad spray pattern). Just get new ones it's MUCH cheaper than getting your engine disassembled again to debug. It's been absolutely flawless otherwise and the huge number of positive posts in the 4.5L owner's thread is testament to that. There's more 911's getting the conversion done too now not just GT4s.
The Deman 4.5 package means bore + nikasil plating (this is huge b/c once your engine is broken in your risk of bore scoring is minimal going forward compared to the stock engine) + custom stroker kit + custom cams. They use Mahle pistons (just like OEM) and carillo connecting rods. When I was there they mentioned they may use Carillo pistons in the future too. Very top of the line stuff. The design is also meant for longevity too. I have no doubts the engine will last as long as OEM. The amount of R&D is honestly very impressive and reassuring. I would purchase a used deman car without the slightest hesitation.
One thing to note is he does request you use octane booster especially if you use crappy west coast 91 fuel. This isn't a big deal at all actually, it's only a tiny bit every fillup and it's easy to keep a few bottles in the frunk and you're set for tons of fillups. I've done road trips with it no problem. This also gives you a nice margin of safety in hot weather.
I haven't had many issues with CELs. Only in very cold weather if you haven't driven the car in a while and the battery is low. But I've gotten stuff like that on any Porsche lol. A quick code clear and you're all set.
Emissions testing works as normal. You just need to set it to a CARB approved tune in california or the stock tune (obviously do not drive it hard like this) and set the emissions monitors. This has always been annoying on 911's so I just have the dealership set them for me (they do some funky drive cycle and PIWIS magic). In CA they sometimes do a visual check but I've never been failed for catted headers. Not much reason to go straight piped nowadays anyways for street use.
PDK happily handles the extra torque. It's naturally aspirated so the torque comes on through the power band so it's not like you slapped on a huge turbo or anything.
As for performance? I mean, the low end torque makes a stock GT3 feel slower (and it's faster in a straight line than a stock .1 GT3RS for sure. On a track depends on suspension setup, etc.). It's pretty insane how hard you can pull even in 3rd gear at 2k RPMs.
As for the rest of the car... the next best upgrade you can do to a 991.1 is IMO the DSC v3 + Tractive suspension. Expensive, yes. But it completely transforms the car and I don't say that lightly. It stays extremely grippy even when the road surface gets uneven. And if the car gets slightly upset from a bump at high Gs it quickly stabilizes without even traction control needing to kick in. Riding around town is also super comfortable thanks to the huge dampening range. IMO this is one of the biggest ways to close (and reverse) the "feel" gap between a carrera and a GT3/GT3RS. The TPC front axle width kit also helps by increasing the front track width a little bit but does so safely without just putting spacers in there. The TPC sway bars also help greatly by helping control body roll. I leave it slightly soft and that's actually perfect because the car feels very predictable but much more responsive than stock (without fear of sudden oversteer, etc.).
I never thought about the Deman Motorsports kit other than for a GT3…but whoa! Great idea and I am sure it’s beastly. Very jealous about that 911R grill you purchased and would love to see more pics of everything.
11-18-2022, 04:56 PM
Dream 991.1 Build Complete!
