An End-of-build Retrospective on my Rx7 Evo GT by gmonsen

By diyauto
( 3 )

6 minute(s) of a 280 minute read

5-9-2013

Didn't see your questions on the last page regarding the secondaries. They are very well-sealed and there should be no leakage. We are controlling it with a carburetor vacuum actuator that runs off manifold pressure. 


 

Also, take another look at the runners themselves. Here they are immediately after being painted, so wrinkling has just begun. But the paint will help you see the design better. Take a look at the area where the bikinis are again and the size of the runner legs...


I'm just going to pop the two final engine pictures back up again.

G



And I think this may become my sig...





5-10-2013





5-11-2013


Tuning? We don't need no stinking tuning. Seriously, it will run pretty well pretty quickly. Logan knows these pretty well and its easier to get these to run at 90% of what's possible pretty quickly when its all you've been doing. While we have the secondary butterflies to stage and the exhaust pipes opening and closing, everything else is essentially the same motor that Logan has been building and built for himself a few years ago. There's a good deal more tuning in turbo setups, because you have another dimension entirely for boost for example. Plus, timing is so much more critical. Anyway, short answer is there's something more than a base map and it won't be hard getting it set for driving and VIR. The trick stuff may or may not take some fiddling.






5-12-2013


With the motor itself getting done, I haven't posted anything much on the exhaust itself. Here are a couple of pictures that show the cutout that controls the second pipe. The butterfly is opened and closed by a cable which is actuated by a solenoid. The other pictures show the in bumper muffler box at the end of the two exhaust pipes. You can see how the box mounts to the frame cross rail. Little integrity of the original bumper is lost. I don't have a picture, but the entire box is covered in heat shielding before the cover is put on.


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Just some more shots of the engine. 

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Zoom zoom today for certain, David. And some good pictures of the car actually sitting on that R888 rubber!

A few people have commented on the mesh screens on the ITB air horns and how it would restrict air flow. We'll do a few runs with them on and with them off, so we'll see what if any actual losses there are with these. Any form of colder air is going to present about as much air to the throttle bodies as the screens do. Unless I lose more than 10-15 rwhp I am not going to change it. I really like having a minimalist engine bay. I wanted as simple an engine as I could make it and its hard to imagine anything simpler than what I have. However, if there is a real issue and I really lose a bunch of power with the screens on, I have a plan. I'll put in a NACA scoop on the hood in the valley on the driver's side. about a foot in from the leading edge of the hood when its closed. The duct will open into a plenum affixed to the underside of the hood that directs the air to the 3 air horns. There would be cold air and a slight ram effect. I've drawn all this out, but don't think we'll need it.




And, here's a really dirty picture of the front end with the smoked turn signals and side marker lights. We'll have it cleaned up by the end of the week.




Comments

Nice job!

Posted by Diggymart on 3/13/19 @ 9:54:43 PM