Waking up after 12 years in the barn – needs more racing DNA

[Benutzername]

Unfortunately, you can’t control the weather, so I had to wait quite a while for a few sunny days—and, of course, for April 1st. That’s when the vehicle’s seasonal registration finally begins. 

Since I had no experience whatsoever with this type of plastic manifold and didn’t want to damage it under any circumstances, I ran a few small tests before taking it out on public roads.To do this, I attached a miniature Type K sensor to one of the mounting screws, where I would expect the highest temperature. The intake manifold itself is thermally decoupled by the 6mm Pertinax plate, but the screws are not. 

So I decided to put the material through a quick stress test. I let the engine run hot while the car was stationary, with the hood closed and no wind coming from the front. The temperatures reached a maximum of 63°C. PA12CF starts to flow under pressure between 90 and 110°C. So it’s not a problem!

Incidentally, the first engine start went surprisingly poorly. The plastic intake manifold has a similar shape, but its cross-sections are slightly smaller. However, further tests showed that the material itself seems to have a relatively significant impact. Anyway—it took a bit of fine-tuning, and then we hit the road. There, too, the new version behaved completely differently, but significantly better! 

 

Overall, at full load, more fuel is required at the same lambda value, and there is a clearly noticeable increase in torque and power. Starting at 4500 rpm, torque increases noticeably and appears to continue growing at a relatively constant rate. The fuel map actually provides a relatively clear indication of how well the engine is performing. The peak at 6000 rpm is less pronounced than in the previous version. This severe resonance (6300 1/min at that time) no longer occurs with this version, contributing to significantly improved handling and acceleration. 

Another factor is the incredibly good cold air supply. The filter at the front of the vehicle does a brilliant job. The intake manifold stays extremely cool. 

The fun ends at 8000 rpm – unfortunately, the hardware won’t allow any more. I reckon it’ll stay that way, because anything else would swallow up vast amounts of money again. 

Next time, I'll be back with a few videos!

Edited April 12 by Benutzername

[mk2]

Yeah, at high RPM, you eventually run out of burn time! The cylinders are too big. I really like the 1.5L V8 race engines that scream all the way to 15,000 rpm! Tiny efficient small cylinders allow much more gas pumping than big slow engines. Do you monitor EGT at high RPMs?

[Benutzername]

4 minutes ago, mk2 said:

Yeah, at high RPM, you eventually run out of burn time! The cylinders are too big. I really like the 1.5L V8 race engines that scream all the way to 15,000 rpm! Tiny efficient small cylinders allow much more gas pumping than big slow engines. Do you monitor EGT at high RPMs?

It is just hardware related - the crank drive is completely in standard condition. Although there are just 268° cams in, the engine want even more revs and hits the limiter very hard, but I am worried about the con rods. 

Yes, EGTs are recorded all the time.