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No, Adaptronic is MAP based, but maybe you should try to reason that through first. On our engines it’s vented into the intake after the MAF, but before the throttle body. So in essence it’s vented to atmospheric pressure, but inside the intake tract. It already went past the MAF and partially through the engine. So why put dirty air; possibly a combination of air, fuel, oil, and exhaust/partially burnt gasses, back into a race engine?
The only way I can see it causing a MAF issue would be if the engine had reverse blowby; sucking air in. That assumes you aren’t tuning for the engine and have it compensated for in the tune, but I suppose that also assumes it’s consistent and not always varying due to certain conditions. Regardless, it would have to be a big number to affect AFR under high engine load conditions, which means you have bigger issues like a failing engine. It might be a factor at idle/low flow conditions, but unless it threatens to create a condition that harms the engine in some way, then why care?
For the record I never saw one drop of oil in the intake of my engines since I bought an RX8 in April/2005. Which I’ve stated on the forum numerous times that such a condition indicates engine health. So on one hand I don’t really consider that to be a factor. Even if I was intending to be MAF tuned I would still do the same thing on a non-emissions race engine.
I'm not entirely sure what's going on here - you're using the aluminum tube with the filter on it as a replacement for the factory oil fill tube which also serves to vent the sump to the atmosphere?
Yes, exactly. I considered a catch can, but as per the previous reply I’m not expecting it to be an issue. What most people call the UIM on the Renesis engine is actually two pieces; the actual UIM is on top, underneath is another bolt-on section that is a combination oil filler pipe/PCV and the vacuum tank with intake control valve solenoids.
So being part of the intake/emissions system, I got rid of that lower section entirely, cut off the vacuum tank/intake solenoid section and remotely relocated it to the RH shock tower for easier access, yet still support the UIM/TB properly. The TB is quite heavy and can’t just be hanging out there bouncing around on the far end of a plastic manifold. There’s a chance a catch can may be required, but I’m opting to try without first for simplicity and min weight.
Worst case I have to run a hose into a catch can with filter instead. No biggie to add that later if needed. Again, removing unnecessary complication and weight, also allows more air circulation/open area between the engine and intake. I might add some lightweight insulation heat shielding to the UIM to keep engine heat from radiating into it.
Yes, exactly. I considered a catch can, but as per the previous reply I’m not expecting it to be an issue. What most people call the UIM on the Renesis engine is actually two pieces; the actual UIM is on top, underneath is another bolt-on section that is a combination oil filler pipe/PCV and the vacuum tank with intake control valve solenoids.
So being part of the intake/emissions system, I got rid of that lower section entirely, cut off the vacuum tank/intake solenoid section and remotely relocated it to the RH shock tower for easier access, yet still support the UIM/TB properly. The TB is quite heavy and can’t just be hanging out there bouncing around on the far end of a plastic manifold. There’s a chance a catch can may be required, but I’m opting to try without first for simplicity and min weight.
Worst case I have to run a hose into a catch can with filter instead. No biggie to add that later if needed. Again, removing unnecessary complication and weight, also allows more air circulation/open area between the engine and intake. I might add some lightweight insulation heat shielding to the UIM to keep engine heat from radiating into it.
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Looks good.
One thing though, and this is just a question, what rule in section 15.10 allows the substitution of the oil filler pipe? Obviously you could have accomplished this while retaining the stock filler pipe and I don't think it's a performance advantage, but I don't see a rule that explicitly allows it.
Well it’s called an “oil filler pipe”; which it has to be given a name for general purposes, but it also has the intake valve control electro-mechanical system and listed as part of the intake system as well as the part of the PCV emissions system; hose connection between it and the accordion tube.
So if you go back to some past rulings; such as the clarification of the plastic “radiator” shroud for the CAI, it is specifically listed as being part of the manufacturers intake manifold parts description/listing; both in the service manual and also the parts documentation/listing. It is not listed as being part of the engine oiling system or any other system.
15.10.C also states “If an induction system item is allowed to be removed and its original mounting bracket can be removed by simply unbolting it, the bracket may be removed as well.”. Which said part also serves as a mounting bracket for heavy TB end of the manifold system.
Well it’s called an “oil filler pipe”; which it has to be given a name for general purposes, but it also has the intake valve control electro-mechanical system and listed as part of the intake system as well as the part of the PCV emissions system; hose connection between it and the accordion tube.
So if you go back to some past rulings; such as the clarification of the plastic “radiator” shroud for the CAI, it is specifically listed as being part of the manufacturers intake manifold parts description/listing; both in the service manual and also the parts documentation/listing. It is not listed as being part of the engine oiling system or any other system.
15.10.C also states “If an induction system item is allowed to be removed and its original mounting bracket can be removed by simply unbolting it, the bracket may be removed as well.”. Which said part also serves as a mounting bracket for heavy TB end of the manifold system.
You may be right that the oil filler pipe is considered part of the intake manifold allowance but I'm not sure it would hold up in a protest. I don't know why anyone would protest such a thing, but stranger things have happened.
Well I have to get it completed and compete well enough first. I don’t see how it can be claimed not to be part of the intake manifold system on a Renesis engine. Which 15.10.C states as being “unrestricted”.
I also forgot to include 15.10.F in the previous reply, “Emission control devices may be modified or removed. This permits the oil filler cap to be modified or substituted but does not allow valve covers or cam covers to be altered to install a breather or for any other purpose”. There obviously aren’t any valve or cam covers on a rotary engine, but I was very careful not to modify the engine mounting flange; which might be considered equivalent to that, in any way.
Obviously not hiding anything, also not trying to torture the rules or do anything different intention-wise than what the factory did in a different fashion. As for weight, it overall weighs more if you factory in the aluminum UIM end and the IGN-1A coils/mounting plate. Pretty sure I can still use the OE piece and have the same coil mount if it was disallowed. The only thing that’d change is I’d need to make a bracket to support the TB end and then the intake solenoids are a pita to access in the OE position.
However if a protest is filed then I suppose we’ll find out how it pans out after a ruling and appeal if judged against. It’s not something I’m particularly worried about. The engine mount deal was a much bigger issue that has no position to stand on in a protest scenario.
Though still a little time left before the cap, it wont be much longer. Seems a few of us arent making it to Lincoln this year, but still at 18 entrants (16 when the miata's realize they are in the wrong class).
After 8 years of Nationals in DSP I'm going to really miss it. Definitely one of the classes I want to watch on my off days. This might be the year an RX-8 takes it.
Went with a few compromises, but the spiral is in. Went the easy route with torca clamps and simple slip transitions, also in part because I did not have much room for extra length and to get everything together in a timely fashion. I didn't want this hanging out there while I'm still waiting on the LCA bushings on backorder with MM. I haven't decided if I'm sticking with the "compromise" 285's on 10s, or slapping down the $$$ on 315's on 11's. Hoping I hear the bushings are on their way so I can mess with the 315s by the Peru Tour.
The Spiral Baffles are well made. Opted to weld them vs. use their existing bolt hardware, also in part to save space as the transition slips would need more pipe length to allow the bolt, I probably left only an inch or two of reasonable length I could add while keeping this easy. (And yes, the bullet muffler is crazy tiny, could not have done much at all) Added the merge collector shot and muffler out back for posterity.
Jim's shop is in a High School in a quiet neighborhood. I opted to not do some real rips to prove it, but a no load quick rev to 4k certainly came across as reigned in. I'll know more on the 21st with some launches at Chicagoland Speedway (complete with walls on each side for an echo chamber).
Looking at the 285 vs 315 tire decision, after Bristol I am fairly convinced there isn't a huge deal to be gained. I wish the other car had been running data so we could have had a better comparison than just overall times to go on. With both courses having a decent bit of elevation change it would be cool to see the differences in acceleration rates on some of the lower speed corner exits. While David edged me out, I would say it had nothing to do with tire size or available grip, my driving was garbage and hitting cones is bad.
Also, his car is running 315s with non-hacked bodywork. They said that the biggest limit was the inner rear (other than limiting steering and compromising alignment). I'd be curious to try the wider setup, but without solid data it still doesn't seem to be worth the investment for a what-if.
For me I would skip the 295 and go straight to 315s because as long as you are going big, go big. 285's have the extra low to their credit. I would still possibly want to look into putting the 285's on 10.5s if I'm staying with them.
For me I would skip the 295 and go straight to 315s because as long as you are going big, go big. 285's have the extra low to their credit. I would still possibly want to look into putting the 285's on 10.5s if I'm staying with them.
Right now Gigglehertz is running 295 with no steering limitations and slightly pulled fenders.
The 295 is not a good tire. It's the same width as a 285 but taller and squishier. Avoid.
The 315 is just a better tire than the 285. It's easier to drive, it's less edgy, it wears better and yes it develops more grip.
I will point out that there was at least one RX-8 last year that had the pinch welds behind the front wheels hammered flat. If I were still in DSP I'd be checking the cars to make sure nobody was doing that. The 315s can fit without any pinch weld trickery.
On my car it was a matter of aggressively rolling the fenders front and rear, adding steering limiters to the front, and maxing out the front caster. I had to trim the rear bumper attachment point and the front corner lamp attachment point. That's really it.
I flattened my pinch welds because SM allows it, and it means more steering lock. But it's really not necessary.
07-01-2019, 08:19 AM
