Falken

What makes a power curve aggressive? Sorry I'm a newbie.

I'm curious as to how the MM turbo behave after 8,000rpm. The only thing I'm worried about is if it takes a tremendous dive like the Mazsport turbo, because I definitely don't stop at 8,000rpm.

MazdaManiac

iTrader: (3)

The motor begins to stop breathing after 8000 RPM. It has nothing to do with the compressor.

mysql

Look at the stock dyno. The engine loses power after 8k. That's just the power curve the engine has. Even if you stuff it with air, you still have the same engine. That's why every turbo kit graphed has similar lines.

I can't speak for the Pettit graph - the chart used in the dyno comparison was taken from a small print out that someone scotch taped to a car window, then someone took a photo of the printout with a camera and posted it online. So for all I know it was hand drawn and pulled out of thin air..

Falken

Sorry I don't know what you mean by stop breathing.

rotorocks

Oh, the die hard supercharger fans
Unfortunately, this is beginning to turn into a circus

Falken

It's an honest question, no need to be forum-ish. I am not a supercharger fan or a turbocharger fan because I don't know enough about either to "decide" which is better.

Hows abouts answering my question? :p /endthreadhijack

eastcoastrotary

i agree with rotorocks that of the turbo dynos, the MM Upgrade is the "purtiest" (still awaiting definition ), except for its drop-off in torque (loss of 50 lb*ft) starting around 6,000rpm. Could that be corrected by modifying engine timing or do you think it's inherent to turbo used?

mysql

Watch the drop in torque in the SFR, PTP, Mazsport, and MM turbos. They are all at the same exact angle. Really, the only differences is where the powerband starts, and that just shows you how quickly the TC kicks in.

Falken

It looks to me like they all do that to some extent, except the superchargers, but those never really produce that much extra torque in the first place.

EDIT: Damn, mysql beat me to it.

rotorocks

OK
Think of it this way: Past 8K the demand for air begins to exceed the supply. And the supply is limited by the volume that can be efficiently flown through the ports (in and out) at the given pressure. At some point the motor simply becomes inefficient.

Ti Carbon

Because more moving parts is less to worry about? Yes it has more moving parts but i was meaning its fiting. Im sure u do make more TQ but now its back to psi and cfm. And like he asked on page 1 hes looking for smooth Hp and Tq. I don't think liquid intercoolers are much better then air to air.. what ever works best for your mods and what ur looking to get out of it is best. Im not pro SC or turbo. what ever is best for what ur looking for..go 4it. Ive owned 2 other tubo cars an luv'd them. Theres always going to be a turbo or sc battle. It does take power to make power with SC, but it seems that sc car run longer with out having to replace or fix the SC then turbo's. An that goes for all FI cars.(just not VW g60)

eastcoastrotary

rotorocks,
i read that whole discussion on the thread you pointed out to me and i must say i was surprised! esmeril did seem reluctant to directly address the issues you pointed out; i hope that chris does and proves his kit to be good.

in the meantime, how do we get around the issue of the slow turbo? do you know if a particular turbo model exists which can reach 300rwhp while being light enough and small enough to maintain lightning spool times? do any of the existing kits use a similar turbo? what about buying an existing kit and upgrading the turbo, as has already happened with Greddy?

regarding the mazsport kit, their dyno seems to have the worst lag of all. i know that the different mount of the type II would use less piping distances and then theoretically have faster spool times. would it be noticeably different on a dyno chart?

also regarding engine response: how does a high-flow cat decrease spool time? what about the FEED 4.77 final gear ratio? they were both mentioned in the thread rotorocks referred to previously (https://www.rx8club.com/series-i-major-horsepower-upgrades-93/esmeril-turbo-kit-dyno-review-146281/page3/) as being detrimental to turbo response.

so many questions! this makes me feel the need to contact a turbo manufacturer to ask his/her opinion about picking a turbo unit and starting from there! it would be oh so much easier if a kit exists that can do this though i guess we'll see....

rotorocks

Chrises kit is good.
Very clean, and estetically well put together. It just not a fast spooling kit.
If you like driving agressively all the time, keeping your revs at 5K and above, you are gonna get a kick out of it. But if you are in the streets of a city, and want to suddenly switch lanes before the space is closed, don't expect it to give you that well needed push..

My hi flow cat is gone as of yesterday.
I was taking off the dump pipe, to make some anti rattle adjustments, and accidentaly droppd it from about 3 feet hight onto a conctete floor. Ding!!! ...there goes the cat.
I hammered the remains out, and now it is just a straigh pipe again.
I saw no notisable increase in spool up time on the turbo I currently have. I hope that sort of answers the question.

To be honest, I never looked at Mazsport dyno until just now, so I guess I effed up on that one

FEED 4.77 ect, blah blah... Just like he's pointing to the dyno with "look, no lag" while it realtively clearly shows no indication of full boost produced for almost 700 revs range, or him telling me that 3' longer charge pipe can be the reason... He is really grasping at straws.
That turbo has a heavy wheel and shaft, and is not sized to spool as fast as he claims.

300 WHP is not that difficult to achieve anymore, and there are plenty of turbos that will get you to that mark while giving you an excellent low end.

Take a look at Turbonetics T3/T04E - T04B series turbochargers. They have a few differently trimmed units that can flow plenty of air, and yet give you an excellent spool up.

avanti_racing08

hey guys new to the forum, and just read threw this entire thread. I just picked up a RX-8 and new to the hole rotory thing. I have been a fan of SC my self more then Turbos but i will be doing alot of rallys and a lil over 300rwhp will be more then enough for me to do those. My question is there any one on here with a SC installed? and how do they like it?

Falken

Don't do anything if your still "new to the whole rotary thing"

avanti_racing08

I wasnt going to throw one on tommarow lol. but does any one on here have the SC system.

paulmasoner

iTrader: (1)

https://www.rx8club.com/series-i-major-horsepower-upgrades-93/pettit-super-charger-owners-127674/


86 pages of design and engineering gone wrong, and end users attempts at fixing it.

all in all not a bad product once you get it all going properly

eastcoastrotary

is it feasible to do something like buying a large quantity of parts from a kit (like Esmeril, for example) and omit the turbocharger itself with the intention of replacing it with a better unit capable of spooling faster? would the internals of the setup still operate properly (besides having to make a new map for the ECU) if the new turbo had similar physical dimensions?

Falken

From what I hear, correctly sizing turbo is a touchy practice that it's easy to screw up and do damage with. I don't see why it's not possible but I wouldn't do it without some expert help.

I'm looking into an expensive but perhaps perfect solution to the turbo spooling problem but no one should expect any word on it for a while.

eastcoastrotary

Care to elaborate?

Falken

I have two ideas both of which are in different stages of patent so I can't talk about it yet. Ask me in a few months.

Look into the new MM/BHR kit. It isn't even out yet but considering the reputation of both developers it's a safe bet this will be a great turbo kit.

rotorocks

There is no problem with spooling a turbo, as long as it is a correctly sized one.
Properly sized or not with incorrect tune you will pop a motor. And expecting OEM like reliability from an after market turbocharged vehicle is foolish. Want a turbo? Accept the risk, or stay away.

eastcoastrotary

Yeah I did look at the MM/BHR kit and it seems like a wonderful option. I'm curious to see how much its numbers/powerband deviate from the MM upgrade to the Greddy kit. I imagine they will slightly, but I haven't cross-checked the parts to list to see what's different.

One thing did confuse me though: the use of Access Port vs. Interceptor-X. I've searched the threads but don't really understand the fundamental differences between the systems. From what I've gathered (which is probably wrong: please correct me!), the Access Port is a means of remapping/modifying/extracting data/etc. the existing ECU device via a laptop and external software, whereas the Interceptor-X is a complete replacement for the ECU computer with its own control software. Is that correct? I also couldn't find any distinct advantages and disadvantages of either (besides the price). Any feedback would be awesome since it affects engine control for the turbo.

Falken

There is a problem with quickly spooling a turbo that delivers high power all the way to redline, that's why we have TT, that's what my little machine seeks to address.

But more on that later.

I can't imagine that MM and CRH have not dynoed their kit yet. I suspect they will release a curve when they release their kit, although I wouldn't mind seeing it earlier.

mysql

uhh.... anyone who has a greddy kit + MM's GT3071R upgrade kit has essentially put together the same kit piecemeal.

It works great. Quick spooling, doesn't have random peaky points or random boost spikes like the greddy did for many of us. There's really no issue that I can think of, and it can provide more power than you're going to want to use.