Tweet
MORE PARTS:
The clutch and flywheel… Not full RSR lightweight… but lightened…
The clutch and flywheel… Not full RSR lightweight… but lightened…
-
-
I wonder why more in the US don't use Capricorn pistons, after all they make pistons for F1 and I think they had a complete replica 4 cam Porsche engine available.Comment
-
Perhaps folks just like to use “more local” suppliers… easier than dealing with customs, international shipping, etc. I guess?Originally posted by flatsixer View PostComment
-
ARNOLD IS ALIVE!!!
The 1st day best run was without the stock type air filter assembly and limited to 7,500, and indicated:
303 HP @ 7,500 RPM (it was still making power when the run was stopped)
315 Nm / 232 Ft Lbs @ 6,500 RPM
The 2nd day best run was with stock type air filter assembly and run to 8,000, and indicated:
293 HP @ 7,900 RPM
319 Nm / 235 Ft Lbs @ 5,300 RPM
The motor got nicknamed Arnold… Long story and goes back to my movie days when I worked on Terminator 2, and my latest race helmet…
As for Arnold the 3 liter motor...
We had achieved our goals…
1) 300+ HP – can make that without a stock style air cleaner
2) 310 Nm / 230 Ft Lbs – either with or without stock type air filter assembly
Interestingly, with the stock type air filter assembly, “Arnold” made more peak torque at a lower RPM and the curve is smoother…
The guys at APP are certain, that they can fine tune it to get more power, and a smoother curve, but we'll wait until we get the final exhaust installed …
And if we really want to be crazy – we could always get Eisenbrandt to make a custom specific space cam for our MFI pump and engine… (https://www.eisenbrandt.eu/kennfelder.php) We’ll see…
Last edited by dwa911; 07-26-2022, 12:32 PM.Comment
-
Sounds so sweet!
Is that a digitally converted MFI pump?Comment
-
Thanks! Love that sound too!Originally posted by flatsixer View Post
Eisenbrandt uses it to dial in the MFI pump on an engine dyno specific to the motor, and create a 3D map to make a space cam specific for an application...
It is about 10k euros when you factor in the engine needs to be on an engine dyno (not rolling road), the technician needs to be there (flights, hotel, etc), the charge for mapping it, and then the charge to create the space cam... If I were racing, then I would definitely do it, as it would probably create a competitive advantage... Or if we built an engine that Porsche hadn't built with MFI, E.g. 2.8SS, or larger than 3.2... perhaps I would do it if we couldn't get it to dial in...
We discussed it a bit, but in the end, Arnold has dialled in nicely...Comment
-
GEARS:
Now we could think about gear ratios…
Without replaying all the effort, time, back and forth, and the immense help from the likes of Bill V, Matt M, Richard T, etc…
We ended up with a slight modification of the SCRS gear ratios – kind of in the middle of the standard and optional SCRS ratios…
SCRS STD
11/35 15/30 21/29 25/27 27/24
3.182 2.000 1.381 1.080 0.889
Schtroumpf
11/35 17/35 21/31 23/27 27/25
3.182 2.059 1.476 1.174 0.926
SCRS OPT
11/35 16/35 20/32 23/29 26/26
3.182 2.188 1.600 1.261 1.000
This set of ratios drops each upshift into the peak torque range roughly between 5,000 – 6,500 RPM… We made a slight concession to 5th gear to keep revs at 4,000 RPM at 80 MPH / 130 KMH… It will be a bit on the short side for extended driving to circuits on the motorways, which may mean not using motorways for extended periods!
Hoping we got it right… If not, we’ll change them…
Comment
-
and for others; here is a link to a gearing calculator with everything you need to play around
https://www.blocklayer.com/rpm-gear.aspx
Comment
-
BACK AT BASE:
Arnold was now back at Differs waiting to get paired up with the gearbox and installed in Schtroumpf.
Comment
-
INSTALLED:
A few days later installed together and ready to test…
Comment
-
First, how Arnold will look with a stock style air filter housing and the ducktail…
Last edited by dwa911; 07-28-2022, 01:58 AM.Comment
-
Then, without… Easier to test & tune...
Comment
-
-
Surprise – Drive By:
And before I knew it – I received this from the guys at Differs…
Comment
-
EXHAUST-ING:
The plan from the beginning was for Schtroumpf to be a road car that would be driven to and on circuit… We were trying to install non-parasitic AC (Classic Retrofit electric AC), and retain heat and defrost functionality…
The AC seems to have gone in without a hitch…
The heat functionality has given us a few more issues… We purchased the large ID Eisenmann heat exchangers and RSR sport muffler… The heat exchangers showed up and looked very nice…
Comment
Comment