SonnyakaPig

They must do it as part of the aftermarket tune if they want to increase power. There are only two factors in a tune that make power: 1) adjusting AFR and 2) increasing spark advance (timing).

I got this information from Kenne Bell who consistently reiterates that point on their website.

SonnyakaPig

Cool.

118E63

Umm,lets not get carried away with "nothing is touching his supra" as youve mentioned it twice already..if that comment is based on the supra racing a car then it may very well be true..but you maybe forgetting about quite a few bikes that would have NO problem having their way with a 1200hp supra...I agree they are stupid fast but hardly the end all when it comes to straight line speed in a street legal package

_AMG_

I have seen Kawasaki ZX14's and Hayabusa's get spanked by 900hp supras. There is no way a bike will keep up with a 1200hp supra.

118E63

Hmmm....let me put it this way: a 900rwhp Supra has no chance against a 550rwhp turbo Busa let alone a 650rwhp turbo Busa.....lets not forget who&what just set the outright stand mile speed redord..that would be a street legal turbo Busa that ran 278mph..any Supras close to that?

And a Gen2 Busa w full exhaust,PC3USB but otherwise bone stock(including stock gearing)ran 200mph at maxton w a 200lb rider on board...there are PLENTY of MODDED ones running in the 220-265mph zone on a regular basis&have no issues being driven on the streets in traffic

I have NO interest in getting into a forum debate as to which is the speed king of the streets;I merely pointing out that when you say "Nothing will beat a 1200hp Supra" there are plenty of bikes that can do it w/out issue

No problem though,most "car only" guys really have no clue as to what hi hp turbo bikes can do

sflgator

Not entirely true...I don't believe RENNtech touches the AFR; my car was still running too rich at 10.2 AFR even after my RENNtech ecu flash tune (which I've heard is the same as stock). Then, Jeremy at OE Tuning leaned it out a bit and I'm now running at ~ 12.7 AFR...and yes, he was able to extract more power!

SonnyakaPig

Respectfully, what other ways can you increase power from a tune without adjusting AFR and timing?

sflgator

IDK. Just saying that I've been told just like you that RENNtech didn't alter the AFR from stock. They did of course change plenty of other maps and my RENNtech ecu flash tune did make plenty of extra HP/TQ just as advertised. However, Jeremy at OE Tuning was able to extract even more power; he also changed many different maps as well as making it so the engine runs leaner at 12.7 AFR instead of 10.2 AFR.

SonnyakaPig

I understand what you are saying completely. I have been told that another tuning company doesn't advance timing in their 91 octane tunes, and if that is so, and Kenne Bell is correct that only two factors are responsible for increasing power in a tune (AFR and timing), then that particular 91 octane tune must have leaner AFR's than stock.

I think this is getting into trade secrets.

MB_Forever

Good post....

Regarding stock AFR, I'm not sure about the 10.2 figure. I think my car was in the 12s as well

LZH

did you really just compare a car to a motorcycle ???? LOL, retarded...


And for you guys comparing tunes/tuners who runs them, who goes to the track, results etc...Take a second and think about the fact that the membership here and elsewhere of people who post on the internet about their cars makes up about 1% of the total AMG owners (if that). My point is, you guys are debating about a VERY small percentage/segment of the population. I've run into people many times who have highly modded AMG's and they have never heard about MBWorld.

bhamg

That 10.x figure is just not consistent with anything I've read or seen, or in my own experience with the C63...not doubting it so much as just puzzled.

*edit* Mine was getting up towards 13 stock.

SonnyakaPig

Thanks. I think that was directed at me. If not, I'm a little embarassed for the presumption.

118E63

Luke,please explain why its retarded? Propain stated that nothing could touch a 1200rwhp Supra..

My reply would inded be "retarded" if Propain posted that *no car* could touch a turbo Supra on the street&then out of nowhere I jumped in screaming "hello hello, a bike can do it"...but thats not the case

Reading comprehension is your friend,after seeing the flame wars youve been invloved in on this forum over the years youd figure you would have learned by now....

dodger63

Good thing we aren't talking about other people other then the ones on this forum!! Let us talk our nonsense thanks..

sflgator

Yeah, I couldn't believe it either and I thought it was very odd that my car would be running so rich especially after my RENNtech ecu flash tune. Maybe it's just my car? Well, in any event, now I'm running 12.7 AFR.

MB_Forever

Yes it was.... I'm sorry I forgot to quote your post. I found the post very interesting I haven't dynoed my car for about a year I think so I can't remember what the AFRs were but I'm pretty sure they were in the 12s except for a brief second near very high rpms. Next time I dyno, I'll pay more attention to AFRs and will break down in as much detailed way as possible

sflgator

But, ultimately, don't you want the AFR to be in the 12's all throughout the rpm band? Prior to Jeremy's OE tune (with my RENNtech tune), from 4,600rpm-redline, I was running no leaner than 11.8 AFR (and 10.7 AFR in upper rpm near redline). Now with Jeremy's OE tune, from 4,000rpm - redline, I'm running no richer than 12.7 AFR.

RStevens63

If you were on a dyno with that air fuel it's because you had insufficient airflow the ECU sensed detonation and began to pull timing and dump fuel. Thats why tuning on a dyno without air makes no sense to me. You are tweaking based on bad info. That's why I want to see track times from these "dyno tunes" you may be locked in on the dyno you were on but that's not the street or track (real world).

Also if someone can't change A/F they have no business tuning, thats a very scary thought who adds timing without adding fuel unless the factory tune is pig rich? Obviously Renntech has the ability to alter A/F, at this point everyone does, no magic there. There are other things like torque management that can affect horsepower production in addition to other changes that some tuners may or may not know about.

Bench racing is fun but real racing is more fun. When's the shootout?

LZH

LOL - I'm fully aware that he said "nothing"...so if you wanna split hairs, cool, but I'm pretty sure he was referring to other cars and not bikes. This is a car forum is it not? And it kind of goes without saying....any "retard" knows that a high hp bike has the win the power to weight ratio department But thanks for pointing out the obvious

RStevens63

That completely depends on the application at hand. 12s are safe for naturally aspirated motors but you don't have to be there across the board. Then consider more timing = more fuel, less timing= less fuel. Timing advance is ultimately a measure of the inefficiency of the engine itself the more you need to run the less efficient the powerplant.

Lots of speculation and guessing going on, I'm ready for results

SonnyakaPig

I read on the KB site that for part-throttle cruising you want 14.7 for feul economy and for peak hp/racing 13.5 would be optimal, but leaning out that much requires higher octane. For 93 octane at redline, 12.7 sounds right where I would like to be.

RStevens63

The only way to get accurate air fuels is to use a dual band AF meter and run it on the street or track at speed. Dyno AF sensors are typically post converters which makes them even more inaccurate.

Excellent points in this thread I am very much looking forward to your next rental results!

RStevens63

That's a very generic statement by KB. They build good superchargers but they aren't world renowned for their tuning by any means. chamber efficiency plays a role, 2 valve or 4 valve or even 3 valve, spark plug placement and count, etc just too many variables to throw one number out there like that.

SonnyakaPig

Good information about what could have caused the 10.2 reading.