Nice man! I can't wait to check it out. I'm still sorting my overboosting issue, but I'm hoping to have it taken care of this week and I'll be dialing the boost in at a "conservative" 11 PSI. With the changes to the boost controller the car is pretty savage now, and boost spools up very fast, but its not stopping at my target pressure.

 

Nah its cool, you know me... I don't care about the S/C vs. T/C war... I guess I just get frustrated with seeing someone asking the question every 4-5 hrs on here.

 

Dude check my sig out thats pretty much how I feel about this forum,,,

 

LOL couldn't agree with you more. Just having fun in this retarded thread. I really don't care about the whole sc vs tc. They are both fun. boost+rx8=sex

 

I think a track comparison between an SC 8 and a TC 8 would be cool, but....

With the large amount of variable aftermarket parts, tuning, setups, etc, it would hardly be "fair". Of course that is a loose term, fair is fair, but the looser would always encounter some sour grapes situation. "Oh I lost because my boost controller wasn't setup right", or "I lost because I was running a conservative tune".

I'm not saying it shouldn't be done, just pointing out the obvious.

I will agree turbos are more brutal and come on harder, since they build boost quicker. Some don't like it, some do. I personally like the feeling of a turbo kicking me back into the seat. Superchargers like the Pettit kit make smaller displacement engines feel like larger displacement motors because they build boost in a more linear manner (RPM/Boost)

 

I've shared a similar experience as well. I will say, for a given boost level, turbo set-ups typically make more power than s/c set-ups. But should I ever go down this road, peak numbers will not be my priority. Instead my emphasis will be on driveability.

I've always found it easier to drive a car with a linear powerband at the limit, than a car with a powerband that comes on in a rapid surge. If a turbo car can be tuned to deliver power in a true linear manner, then I would definitely consider it.

 

Saying turbo cars cant/dont have a linear powerband just isnt true.

 

yeah just don't get the esmeril kit if you want a linear power band instead of an on/off switch for power

 

That looks pretty damn Linear to me.

 

air is air-its all in the tune and set up.
OD

 

not to rain on your parade... but that graph is plotted against MPH, not RPM. not saying it ruins the impression, but it certianly could alter it some.

But more to Symbiotic(and others) point, anyone who doesnt understand that a TC can deliver power in a linear fashion does not understand electronic boost controllers. Course most people like the kick in the seat feel vs the linear feel, I prefer linear


EDIT: OD just hit it on the head... it IS all in tuning and setup. fuel/spark/, boost control/WG setup etc

 

While I understand why this could be very true, one thing you can almost never tune out completely is turbo lag (w/o adding an expensive anti-lag system).

With a minimum weight requirement of 2,700lbs (2 rotor 13B w/ FI) in Street Mod, I'd want a FI that would be able to produce at least 400-420whp with as little lag as possible. I'm not aware of any s/c system that's currently able to make this kind of power, which is why I want to wait for the 16X renesis to come out before making this decision (minimum weight would rise to 2,760lbs).

 

Clearly you have no understanding what turbo lag is.

 

The problem with turbo lag is that the higher your target power number the more lag is going to accompany it. For a drag car or a dyno queen it doesn't matter as much but getting a 1.3L motor (even a rotary) to churn out 400+ whp without any lag is tricky. The Renesis is even more difficult because of the side ports and higher compression. There is no kit that is regularly putting out those numbers on an otherwise stock Renesis with or without lag. The only company that even advertises 400+ whp bolt-on is Esmeril and as far as I'm aware only Chris from Esmeril has taken the kit above 400 whp and kept the engine intact.

The 16X might help a lot for hitting those numbers because of the extra displacement, but depending on the rest of the engine design, maybe not. If Mazda releases another NA car the engine will be high compression, and I don't see them losing the side ports for economy and emissions reasons if nothing else. If you really want to hit 400+ hp rotary with no lag, I would recommend an NA 20B like a lot of the pro teams use.

 

i can think of a couple of turbo's off the top of my head that will support 400whp flow, AND make positive manifold pressure well under 3,000rpms... hell, even under 2500. these arent any big secret either, they've been all over the forum...

 

.......

 

Andy and Erik seem to be doing OK with a single turbo in SSM.

Just put Andy's engine and trans in a SM RX-8.

This years winner:
Thanks, everyone, for the encouraging comments!

I just want to point out that you don't need huge power for a competitive SM car. I'm at 300 hp and 270 tq on the Dynapack dyno at Church Automotive, and the car weighed in between 2597 and 2606 on the scales at Nationals.

From STU, the basic package includes the flares, motor, tuning, stiffer springs, AST 5200s, composite hood and trunk, aluminum doors, a slew of small weight reduction efforts (like yanking out the back seat) and 285s. I still think the 245s on narrower wheels would be quicker on highly transitional courses.

Mike

 

clearly you have nothing of value to add to this thread.

 

I'm correcting ignorance. You're blowing smoke up my ***.

 

all snails are made from crushed up puppies

all blowers are made from used soda cans

unless your AFR is exactly 14.2 you'll blow your motor

all FI cars will blow up their engines at some point

one thing you can almost never tune out completely is turbo lag

These would be examples of me just saying things without giving any information to back them up... aka "blowing smoke up someone's ***".

 

Alright, in fairness, yes they can make positive pressure, but even some of the overly sized turbos can make positive pressure at low rpm, they just won't be in full boost for some time.

Also, a turbo may be capable of hitting 400 whp worth of flow, but hitting that target reliably on a Renesis motor isn't easy at all; lag aside. I mean, in all of the boosted cars on this forum we have had -1- dyno that is over 400 whp and the car was running E85 with a mod sheet longer than my arm.

Edit: Just to clarify, I'm not bashing you paul, or arguing with anyone... I just get nervous when people say 400+ whp on a Renesis because its a major task with this motor.

 

Good info Isley. While Andy's engine would be a legal swap, his trans would not be based on my understanding of the rule book. Since the RX-8 comes with a 6MT, wouldn't I need to use a trans with a similar number of forward gears in SM? Good info on Mike's car -- hadn't come across that before.

Blackenedwings kinda touched on what I was getting at a few posts up. I agree wholeheartedly that a NA 20B would be a good way to have a powerful lag-free rotary. However, I wasn't aware that 20B's were able to hit 400+whp w/o a peripheral port? I didn't think peripheral ports were legal in Street Mod...but instead allowed in the Prepared classes??? Either way, even if they were legal, I'd want my car to remain very streetable, and a peripheral port would be completely out of the question for my tastes/preferences of what I could drive on the street.

Also, in Street Mod a n/a 20B would carry a higher minimum weight, make it harder to meet sound at strict sites, and be a potentially heavier mass sitting near the nose of the car compared to a 2 rotor with FI. All minuses in the world of autocross imho...

One other thing I'll add, I've never once said in this thread that one form of FI was better than the other. I've only talked about my experiences/preferences. I've owned two turbo cars before and loved them. I can accept that others will have a different point of view, please respect the fact that I can have a different opinion for what I'd want to drive in an autocross setting.

mysql101, while I may be ignorant in the world of forced induction rotaries, I'm not behaving like a jackass who adds nothing to a thread other than insults. You're not correcting ignorance, b/c I've yet to see a single meaningful contribution from you. Either way, even if you did start adding sound information, why would anyone want to listen to someone who presents themselves in this manner??? If you chose to stay in this thread, please quit with the insults...mkay?

 

agreed

 

Exactly. Which is why I don't want to go down this path until I can either afford a proper Renesis built for forced induction (Pettit rebuild with larger intake and exhaust ports) and/or until the 16X Renesis is available (and the viability of this engine for FI is determined).

 

cool Be aware that with the current blower being used, you wont get near 400 wheel without some serious charge cooling(ie injection) hell, you'll be spraying something to do that with any of the TC 'm thinking of too, but not necessarily as a matter of necesity - now that i think of it, I can't remember if you said that was a target, or if it was just an arbitrary #

also, exhaust ports are whats limiting the motor in terms of flow capacity right now, and unfortunately they cant get any larger. you can reshape them to a degree and yes technically increase their size, but only on the miniscule of scales.