Just curious, a good reason of why I wanted a RX8 was because it WAS naturally aspirated. I own a Mr2 Turbo, and to tell you the truth. They are a pain in the ass. To deal with, to worry about, and etc. I liked the rotary because (i'm pretty mechanically inclined) they are generally very simple.

The Mr2 however, is emo as hell.

How much is to be expected from a generally bolt on RX8 make roughly? I've done a search and couldn't find anything relevant to my question. just TURBO TURBO SUPERCHARGE SUPER CHARGE on this forum.

: ) thanks

not alot mate, 220whp max? if you tune it maybe 230

If you break 200whp you're doing great

i believe TEAMRX8 has the highest NA hp which is around 220
but i think most of his modification is custom

I believe some people have gotten close to 230 (with pretty much open exhaust). Many people get to around 210-220 with a cat delete and tuning... I would say 200 is the genuinely street legal cap.

That seems about right. Thanks a bunch. The 8 still has awhile left on its warrenty, i didn't really want to bastardize it any by adding mods to it quite yet when I have a Mr2 sitting around.

Thanks for the input!

suspension, open exhaust and throotle response is the most you can do i think?

We've dyno'd at 215rwhp and that's through some power-sapping high angle CV joints and a 20 year old van gearbox...

highest i have seen without addition ecu tuning is about 204 in a daily driver.
olddragger

We've dyno'd at 215rwhp and that's through some power-sapping high angle CV joints and a 20 year old van gearbox...

Uh what?

suspension, open exhaust and throotle response is the most you can do i think?

lol there we go with the throttle response again!

Uh what?

It's not in an '8 :)

The Evolve engine was rated at 280 hp back in 1997. I think with a stand alone engine management system 6 throttle body butterflies and some streetporting at last a really innovate header would yield 300+ hp!

/Lasse

The Evolve engine was rated at 280 hp back in 1997. I think with a stand alone engine management system 6 throttle body butterflies and some streetporting at last a really innovate header would yield 300+ hp!

/Lasse

I'm pretty sure I read somewhere that the theoretical absolute max. for the motor was around 260hp at the flywheel .....

I'm pretty sure I read somewhere that the theoretical absolute max. for the motor was around 260hp at the flywheel .....

Sounds about right; I think that was my math on someone's tuning thread....

Assume a VE of 100%; then figure it out.

VE of 1; RPM at 9000; displacement at 80 cubic inches; BSFC at .60

you can play with the BSFC if you want; but since we are all guessing anyway the point is how much air can this motor move in a perfect world at redline?

Someone on rx8 posted a dyno of 235 or 240whp a while back, can't remember who.

Someone on rx8 posted a dyno of 235 or 240whp a while back, can't remember who.

220 is highest seen on this site ....

Sounds like they had the dyno operator calibrate the machine to be overly optimistic. If you want to fudge a dyno result, you may as well just photoshop it instead of playing stupid games.

Mine is....heh

220 is highest seen on this site ....

For now! :lol: :lol:

yeah 220 230 it about it for N/A

imo 230 is a bit optimistic, look more for ~210 range. Team's 219/220 was on a Mustang which is pretty unbelievable!

these people who hit these numbers... what are they doing? going as far as porting and all that expensive stuff right?

Someone on rx8 posted a dyno of 235 or 240whp a while back, can't remember who.

That was a peripheral port intake motor by Mazdatrix I believe

I think with some porting, tuning, and aggressive mods one could reach 230-rwhp but it wouldn't be too streetable.

Most people opt to go turbo/nitrous/super because it's cheaper per horsepower than going NA


Sounds about right; I think that was my math on someone's tuning thread....

Assume a VE of 100%; then figure it out.

VE of 1; RPM at 9000; displacement at 80 cubic inches; BSFC at .60

you can play with the BSFC if you want; but since we are all guessing anyway the point is how much air can this motor move in a perfect world at redline?

Ok, I'll do it

I kept the Brake Specific Fuel Consumption at .60

I increased redline to 9400rpms

Gave the motor a VE of 98%

Operating at sea level (14.7) and 85 degrees

Mass Flow Rate (MFR) is 31.09 LBS/Minuet of airflow

ROUGH estimate of crank horsepower would be around 310.9 (MFR X 10)

More likely would be around 281-bhp

I would post the math but I'm tried as it is


Also, I guess I should have prefaced this with that horsepower numbers are all relative, anyways, especially wheel-horsepower due to so many variables. I would be more interested in track times, personally.

Also, I guess I should have prefaced this with that horsepower numbers are all relative, anyways, especially wheel-horsepower due to so many variables. I would be more interested in track times, personally.

I would agree as real world performance value is really the big picture we are interested in, though since I am pushing an N/A setup and my nitrous is 6 months (or longer) out...this topic is of interest to me.

At least with regards to the accessport, there hasn't been any attempts to mess with timing. I'm looking to get some dyno time as soon as the weather here in Phoenix cools down.

I would really like to see 220whp N/A with intake, full exhaust, and ignition coil upgrades. I have smaller stuff like the agency power pulley and lightweight:lol2: alternator and water pump pulleys as well.

Anyway, it's all talk at this point but once I have some hard numbers I'll be eager to share them.

I've only gotten them up to 225, +/- 3.
That is with the MS/AEM intake, custom header, exhaust and the AccessPORT.

There might be some that are higher, but that is my best "consistent" number (meaning, it hit more than once on the same motor at different dynos and on different days).

I've only gotten them up to 225, +/- 3.
That is with the MS/AEM intake, custom header, exhaust and the AccessPORT.
.

did you get a look at the header - what was the design ?

did you get a look at the header - what was the design ?

Of course I did.
Long. Very, very long.

like all the way back to the muffler long ...... How many pipes ?

Three pipes, collector ended where the back of the CAT would be.

hmmmm - that's what Hymee did to good effect a couple of years ago ....

So.. without getting shot down for not doing a good search,--- How many and how much more power gain in doing porting-- opening up the std ports, and adding a bridge port??.
Some one in the rx7 forum (a few years ago) removed a Lot of metal (meat) off the sides of the rotor--so that the ports were opening sooner, and closeing later, has this been tryed on the rx8??
Didn't Scoot get something like 700 + ps out of a combo port (both side and P.Ports) on a Batman?? has anyone try that??

Three pipes, collector ended where the back of the CAT would be.


Were these (are) on the Market? , or were these pipes Custom made??

The water jackets on a Renesis are too close to the ports for any serious porting. You can smooth and alter the path slightly, but that's about it.

my car is making 330rwhp with 433 tq. I recently installed a VTEC with ETCS y0

:lol:

Team's Rx-8 has AC delete. So its not surprise that he has the highest hp around :)

[QUOTE=rx8 man;2591478]So.. without getting shot down for not doing a good search,--- How many and how much more power gain in doing porting-- opening up the std ports, and adding a bridge port??.
Some one in the rx7 forum (a few years ago) removed a Lot of metal (meat) off the sides of the rotor--so that the ports were opening sooner, and closeing later, has this been tryed on the rx8??
Didn't Scoot get something like 700 + ps out of a combo port (both side and P.Ports) on a Batman?? has anyone try that??[/QUOTE

Just been looking on rx7 forum, found the posts by the guy, most of the pics are gone, bar a few.

I would agree as real world performance value is really the big picture we are interested in, though since I am pushing an N/A setup and my nitrous is 6 months (or longer) out...this topic is of interest to me.

At least with regards to the accessport, there hasn't been any attempts to mess with timing. I'm looking to get some dyno time as soon as the weather here in Phoenix cools down.

I would really like to see 220whp N/A with intake, full exhaust, and ignition coil upgrades. I have smaller stuff like the agency power pulley and lightweight:lol2: alternator and water pump pulleys as well.

Anyway, it's all talk at this point but once I have some hard numbers I'll be eager to share them.

I think you could get there, Todd, it will just require a lot of time and money. You may be able to go higher (as shown by my math) if you do porting and can increase the effective volumetric efficiency.

Either way, I want to be at the dyno next time! No more secret dyno meets!

One of the guys on rx7 club, who beveled his rotors got back to me, here are the pics he sent to me.
Could this type of thing work on the rx8 13b?

Thanks for the info and pics justin :)

I think you could get there, Todd, it will just require a lot of time and money. You may be able to go higher (as shown by my math) if you do porting and can increase the effective volumetric efficiency.

Either way, I want to be at the dyno next time! No more secret dyno meets!

Honestly I'd try to see what I could get without the porting. The idea is to find the max horsepower of my motor through typical means. I might look into porting down the road when I have another vehicle to daily drive.

I imagine my best would be with an intake/headers/exhaust combo with a lightweight flywheel setup. Add some tuning and an ignition upgrade to that mix and that would be about it.

For max power, one of the incremental steps is a good premix.

Racing Beat dyno'ed 4 h.p. with a 75:1 ratio.......

Quote - While undertaking development work on the RX-8 Renesis engine for SCCA T2/T3 use, we decided to introduce extra oil into the fuel to monitor the effect. To our surprise, this additional oil increased power! Further dyno testing found that by adding 10 oz. of Royal Purple 2-Stroke Oil to 6 gallons of fuel, we gained an average of 1.7 HP from 2000-9000 RPM, along with an increase in peak power of 4 HP. We validated this increase by changing back to a “non-oiled” fuel - and the power returned to the previous level. Later, we tried the same test with another brand of synthetic oil with nearly the same results.

For racing applications, the addition of a high quality synthetic oil increases power and most certainly decreases wear. The only negatives are the cost of the oil and an increase in the tendency to foul the spark plugs.

S

Cheers Stealth TL, I use to pre-mix with the 20b, but that was a case of having to, from what you have posted in the above text, you have made me thinkiabout looking into pre-mixing again. :)

to me.. having a powerfull NA rotary is more bling than a turbo'd RX8..

Turbo charged cars come with their own issues that alot of N/A people dont come across.

Boost creep
Turbo lag
Always being weary of the A/F ratio
Turbo Cool down after every drive
More things that can go wrong
Heat Soak

Just my opinion of course.

There's more turbo lag on a NA rx-8 than a turbo one.

edit: on a properly sized turbo. :)

Power to weight ratio, man.

Just strip the RX8 of 800 lbs and you're g2g.

There's more turbo lag on a NA rx-8 than a turbo one.

edit: on a properly sized turbo. :)

By the very defination of turbo lag that's impossible :squint:

^^ lol, you know what he means :)

Speedsource dyno'd 260hp at the crank on their ST class Renesis race engines. I think that's probably the number we should be shooting at without serious internal design changes.

Although it would be interesting to have some of the RX7 folks take a look at our Renesis rotors and see what they think.

That is with the Bosch stand-alone engine management.

So does that mean you can get more with the AP?:)

That is with the Bosch stand-alone engine management.

Is that Stand alone any good?? How is easy was it to use, I wonder??

So does that mean you can get more with the AP?:)

No. Should be about equal, though the Bosch tuners usually give up a bit of low end performance by altering the intake valve timing and such.

It is important to note that there is a definite difference in what can be realized by "general" tuning based on basic data logging and the results of running a car on the dyno in a closed environment for hours.
When I work on purpose-built cars, it is not unusual to spend 4 or more hours and dozens of pulls just on the fuel curves alone.

By the very defination of turbo lag that's impossible :squint:

Of course. But the actual "lag" as described applies far more to a NA rx-8 than a FI one. With 9 psi of boost and as low as 2800 rpm, I already have MORE torque than a NA car at it's peak. And it just keeps going all the way to redline. Oh, and the 3071R can do 12 or even 14 PSI of boost at similarly low rpm ranges.

A NA setup really needs to hit 5k range to get going, and even then it's pretty uneventful.

No. Should be about equal, though the Bosch tuners usually give up a bit of low end performance by altering the intake valve timing and such.

It is important to note that there is a definite difference in what can be realized by "general" tuning based on basic data logging and the results of running a car on the dyno in a closed environment for hours.
When I work on purpose-built cars, it is not unusual to spend 4 or more hours and dozens of pulls just on the fuel curves alone.

Absolutely agree. I guess their car should be considered the highest we should ever expect to get to NA. EG: They represent the experimental limit.

Unless the ST class has some rules restriction that leaves something big on the table that we can do on the street.

ST rules prohibit them from altering anything from the throttle body to the exhaust ports, so the insides of the motor and the intake manifold are off-limits.

Speedsource dyno'd 260hp at the crank on their ST class Renesis race engines. I think that's probably the number we should be shooting at without serious internal design changes.

Although it would be interesting to have some of the RX7 folks take a look at our Renesis rotors and see what they think.

http://www.rx8club.com/showthread.php?t=153312

Stock motor with Racing Beat bolt ons at 224whp. What's the driveline loss? 15%? 17%?

224wph x 1.15 = 257hp at the flywheel

224whp x 1.17 = 262hp at the flywheel

:eyetwitch :eyetwitch :eyetwitch

http://www.rx8club.com/showthread.php?t=153312

Stock motor with Racing Beat bolt ons at 224whp. What's the driveline loss? 15%? 17%?

224wph x 1.15 = 257hp at the flywheel

224whp x 1.17 = 262hp at the flywheel

:eyetwitch :eyetwitch :eyetwitch

Nice. So 260 with bolt ons and tuning. Seems to be consistent with what I was saying.

Now if someone has some dyno information with a ported motor...Ray...;)

http://www.rx8club.com/showthread.php?t=153312

Stock motor with Racing Beat bolt ons at 224whp. What's the driveline loss? 15%? 17%?

224wph x 1.15 = 257hp at the flywheel

224whp x 1.17 = 262hp at the flywheel

:eyetwitch :eyetwitch :eyetwitch


sorry it was 208 RWHP on a Mustang dyno, 224 is a fantasy number

the 220 RWHP graph was the last of 10 similar back-back runs made that day on the Cobb Mustang dyno dialing in the fuel ratio, the best peak graph was several HP/TQ values higher that occurred with 14.x AFRs that were too high for my comfort. Your AC doesn't run at WOT, not having one is a greater effect on weight distribution than engine drag, but that this output was fully emissions legal is where my pride in the numbers is; no CELs or CEL-deletes and easily passed the tailpipe sniffer test

The Speedsource/GrandAm engines quoted are blueprinted with ceramic seals and MoTec ECUs, they are not emissions legal having cat and air injection deletes etc.

and a certain somebody needs to quit playing number games and say what dyno he's using, which is historically known to read much higher than a Mustang dyno. You can't accurately compare dynos, but there are some variations between them that help put the numbers into context. In the end, it's just a numbers game anyways .... emphasis on game

and finally, multi-tube Renesis header dreams are for 'tards, some people will never accept fact over fantasy :lol:

The Speedsource/GrandAm engines quoted are blueprinted with ceramic seals and MoTec ECUs, they are not emissions legal having cat and air injection deletes etc.


Bosch, not Motec.

and finally, multi-tube Renesis header dreams are for 'tards, some people will never accept fact over fantasy :lol:

Tell that to Roar, Pipelayer and Brass Mitchell.

and finally, multi-tube Renesis header dreams are for 'tards, some people will never accept fact over fantasy :lol:

And some people are too stubborn to accept any idea that contravenes their own...:lol:

And some people are too stubborn to accept any idea that contravenes their own...:lol:

you can afford to be cocky with results to back it up, I walked the walk, talking the talk is all anybody else has been capable of

you can afford to be cocky with results to back it up, I walked the walk, talking the talk is all anybody else has been capable of

:squint:
We've had our car running our header for 3 months, we're happy with it, thanks.

lets see the dyno that backs it up as being something more than special :dunno:

the whole issue is whether or not a tube header makes any real difference. I went against the grain to prove that on a zero-overlap timing engine that it not only doesn't make any difference, going to large sizes doesn't hurt lowend powerband either etc.

anybody can build a header, maximizing Renesis output is an entirely different matter

Yet there is quite substaintial theory already present by several, including myself, to show that resonance effects can still benefit the rotary, yet you simply ignore it and blow it off as 'well I've built this and works'.

Well, I've built a different one, and it works.

well getting back onto the actual thread topic, I proved my theory here on the forum with a dyno from an extremely reputable company to back it up, I did this entirely on my own interest without any commercial intent, I have no need to make marketing claims etc.

FWIW they all work

the question is by how much, when, and where

my claim is that you won't find anything that I already did with a much simpler, less expensive design

if you can prove otherwise, I'm listening ...

Bosch, not Motec.



Tell that to Roar, Pipelayer and Brass Mitchell.

The Speedsource ST class cars used MOTEC. Bosch is mandated in DP and GT

ST is mandated for Bosch or OEM as well.

Gave the motor a VE of 98%

.

mazda published the VE of the renesis engine in the SAE paper. at 8500rpms its more like 105%

they dont give a bsfc chart for anything other than 1500rpm unfortunately

my claim is that you won't find anything that I already did with a much simpler, less expensive design

if you can prove otherwise, I'm listening ...


Ok then, we're pretty free over winter as we've built all the new cars for next season already, if you don't mind me having the pipe lengths, bend radius, etc, of your header, we'll fab one up when we have chance and do a back to back dyno with our own.

:dunno:


edit: dyno graph deleted so bite me, it's irrelevant now anyways :smoker:

^^ Shrink that sh*t!

lol, caught me before the edit, attached the wrong file ...

Not much use to me for a back-to-back comparison though...;)