4 Rotor AWD FD RX7 | @RobDahm 1240HP+ Quad Rotor Build #techtalk This is a big one full of tech and some interesting A-B part testing insights.
Running an R32 GTR transfer box off the back of a Holinger RD6, Winters Quick Change rear differential, Haltech R5 NEXUS ECU/PDM, Garrett 94mm OR 106mm turbo, Clearview oil filtration system along with Ti Automotive a dual brushless pump setup among a long list of other parts, we caught up with Rob Dahm at SEMA to discuss his ever evolving and now essentially complete FD RX7 quad rotor build.
The Haltech R5 doesn't just handle engine management; the built-in PDM also controls many of the electrical components leaving the car without fuses or relays. A standalone Ecumaster PMU splits this duty in 2 adding redundancy plus more inputs and outputs. A FuelTech FTSpark Capacitive Discharge Ignition (CDI) also helps in the ignition department. Interestingly this build draws 80amps at ignition, and as you can see (and hear) Rob has made sure that isn't an issue with this setup.
Traction control is also handled by the Haltech R5 via a Nissan ATTESA-based control system and some 'fettling' by Rob which allows him to demand a dynamic or set torque ratio between the front and rear of the car allowing for versatility when launching and cornering across many surface conditions. We also touch on some Nikasil-style coating that is used to make sure aluminium and steel alloys play together nicely. Interestingly the engine is clearanced specifically for Valvoline 20-50 oil which shows the level of detail this build has reached.
The long list of topics continues with Precision Engineering eccentric shafts, rotary irons, apex seals, 16 point total TPMS (tyre pressure monitoring system) and the gremlins auxiliary systems can cause a rotary engine.
Last time we spoke to Rob he mentioned his interest in more A-B testing, and he has followed through on this and discussed some poor injector placement and cooling issues that upon investigation and data collection he has resolved often by taking it upon himself to learn the skills to do the job himself. Machine work, wiring and tuning are just a few skills he has picked up as a direct result of this build.
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TIME STAMPS:
0:00 - FD RX7 AWD Tube Frame 4 Rotor
0:24 - Even More Hands On Since Last Chat
1:38 - Style Props
1:48 - Put Your Mind To It, Dive In
2:01 - Theory Vs Reality: Intercooler Example
3:15 - Injector Data & Placement (For 16 Injectors)
3:58 - 4 Rotor Engine Development
5:05 - Machining Demands
6:29 - Billet Rotary Irons
7:42 - Clarification on Coatings & Metal Combinations
8:16 - X-Raying For Metal Composition & Data
8:59 - Cooling - Cast Vs Aluminium Testing
10:20 - No OEM 4 Rotor Parts
10:37 - Eccentric Shaft Support & Improvements
12:20 - 8,000rpm and 1240hp, Things Bend/Flex
12:46 - Rotary Reliability Testing: Ridigity
13:38 - 39psi Vs Ken Block Dowel Example
14:40 - Torsional Forces At Launch
15:04 - Porting: 4 Rotor Setup
16:06 - Peripheral & Semi-Peripheral Port Explanation
16:50 - Apex Seals Vs Porting
17:42 - Apex Seal Purpose & Options
18:38 - Apex Seal Scanning & Heat Treating
19:40 - Best Apex Seal.....For What?
20:40 - Stock Seals & More Torque Than An LS V8
21:38 - Electronics: Haltech R5 Nexus
23:12 - R32 GTR ATTESA Based Traction Control System
24:00 - Torque Split Explanation
24:20 - Launching Strategy
25:41 - Haltech R5 Thoughts and Logging
27:26 - PDM - Power Distribution Module
28:16 - Ignition System
28:53 - Spreading Electrical Load
29:34 - Rotary Problems Come From Auxiliary Problems
30:10 - Rotary Engine Reputation
31:59 - Thanks Rob
31:32 - Do What Rob Did And Work On Your Own Project, Big Or Small, It Doesn't Matter
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Want to learn how to wire your own project like Rob here has? Come along to the next free lesson.
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