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-   -   20B's performance margin diminished due to AI (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/20bs-performance-margin-diminished-due-ai-729139/)

zinx 02-13-08 06:20 PM


Originally Posted by MAXX65 (Post 7863765)
So what’s the catch?

There are a couple little ones but overall AI is worth their weight in gold.

If the system fails and you're at full noise, it can be bad news. Most newer systems have good failsafes built in, but its still another point of failure and it adds complexity to your system.

Another one, i've heard of a guy that was using 100% Meth (like myself and many others) and hit his rev limiter which was a fuel cut type, but that didn't cut fuel to the meth system, it leaned out and grenaded the motor. I don't know if thats true because it seems like the mixture would be too lean to even ignite, but never the less, i always use an ignition cut rev limiter now.

ErnieT 02-13-08 06:36 PM


Originally Posted by zinx (Post 7863877)
The more power you make, the quicker the pulls are over. Its safer really. ;)


j/k j/k I understand. I'm trying to get away from doing anything on the street but its hard when someone needs to get beat.

Got any more info on those one piece axles from DSS? He was telling me they were developing them when i stripped a spline of his stage 5's.

They should be ready here in the next couple weeks and will be the standard from now on for our cars, but the price will jump from $550-$1000. But it will worth its weight in gold.

zinx 02-13-08 06:42 PM


Originally Posted by ErnieT (Post 7863985)
They should be ready here in the next couple weeks and will be the standard from now on for our cars, but the price will jump from $550-$1000. But it will worth its weight in gold.

Not too bad really. Plus i can sell off my current DSS axles and not be too far back.

Gorilla RE 02-14-08 01:29 AM


Originally Posted by howard coleman (Post 7849338)
hey, it's minus 10 degrees today so i thought i'd throw up something to chew/war on...

maybe some of you haven't visited the Auxiliary Injection Section. since we all run turbos here in the FD section we all run into hp limits in the form of KNOCK.

if we have modded our FDs some of us add racegas at $10+ per gallon, hit the dyno and crank up the boost. whoopie! 550 rwhp. neat. the only problem is back in the real after/dyno world we pull up to the pump and fill our tanks w 93 octane gas.

horsepower looks a bit different on pump. one bar, 400 or so hp.

that's old school.

enter AI.

the equation looks alot different with the help of a little alcohol.

hp on the street is no longer KNOCK LIMITED

crank on the boost til your turbo is maxxed out on the street. if your tuned right you will be looking at less than 10 on your PFC knock log!!!!

this changes everything including your choice of turbos but that's for another thread.

getting back to this thread...

so you can make 550-600 rwhp on the street w 93 pump and your motor will show better metrics (lower knock etc) than 93 at one bar w no AI.

many of the guys doing the 20B route did it for more hp. 400 on the street left something to be desired. add 50% more rotors and you add approx 50% more power. 600 or so rwhp.

the difference between a 400 rwhp FD and a 600 rwhp FD is not easily imagined. in order to appreciate the additional hp you literally have to be holding on to the wheel of a 600/FD.

w 600 rwhp you can make the car go sideways at over 100 mph in 4th gear. easily.

at a certain point you have to ask yourself.... do i really need rwhp i can't use?

20Bs have made 1200-1500 rwhp on methanol. 13Bs make 1000 rwhp on methanol.

my point is you can NOW (w AI) relatively easily make 600 rw w a 2 rotor w AI.
so exactly where are you going to be able to USE the additional hp above 600 that the 20B provides?

of course for the 10 people on this board that want to really run in the 9s i fully understand. but if you are one of the 100 or so that have done the 20B swap for a dual purpose FD...

ok, if you did it for the unique-ness i am with you 100%. if you did it for the performance advantage, uh, there's no advantage in useable performance V an AI 2 rotor.

further, while it sounds pretty easy to do a 3 rotor conversion it is not. you run into clearance issues w the steering rack and end up with a bumpsteer nightmare.

bump steer is death. stock car/circletrack/shorttrack guys set bump steer w a feeler gauge! that'show important it is. the last 20BFD i did a bumpsteer curve on had a half inch of bump steer at 2 inches of bump.

yes you can set the engine back and do a few things... you can fix just about anything, but you better not move the rack. to those who have, show me your plotted bump steer.

i am not anti 3 rotor. it can be done right. i am just saying that the real world margin of performance is now close to nil.

don't know about AI? we have lots of threads in the section. read up.

howard coleman

Hey Howard,
I'm in support of AI %110, but to me the biggest difference in the 20B vs. 13B(with AI) is the boost level and reliability. A 13B @ 23psi on AI has NO WHERE NEAR the reliability of a 20B @ 16psi NO AI.
-J

ErnieT 02-14-08 05:45 AM


Originally Posted by internal comsucktion engi (Post 7865569)
Hey Howard,
I'm in support of AI %110, but to me the biggest difference in the 20B vs. 13B(with AI) is the boost level and reliability. A 13B @ 23psi on AI has NO WHERE NEAR the reliability of a 20B @ 16psi NO AI.
-J

Not true! Especially at such a low boost level.

Howard Coleman 02-14-08 06:53 AM

"A 13B @ 23psi on AI has NO WHERE NEAR the reliability of a 20B @ 16psi NO AI."

i am going to respectfully disagree w the "NO WHERE NEAR " part of your statement. if you were talking heads up between the 13b and 20b BOTH W AI them i would of course agree that there would be somewhat of a reliability advantage. i am not contending the 13b/AI would be superior to the 20b/Pump w re to durability, only that it would be not materially different.

you have the 20b on pump. it would be making 600. the 13b on pump and methanol would be making 600.

if tuned correctly the 13b will run fine at that level with approx 25% of the pump removed and replaced w methanol. intake temperatures will be under 32 degrees F and knock will be less than 10 on a PFC.

gasoline autoignites at 660 F

methanol autoignites at 858F

that said, there is a point w the 13B where the crank starts to bend due to the torque produced and the lack of a center main bearing. this point isn't much further than 600 rwhp. the shaft bending is probably the engine's limiting point given proper fuel (AI) and tuning.

of course you can install a center bearing, lose the pump and make 1000 rwhp w a 13b. my friend runs in the middle 7s w his and has gotten over 20+ runs at that power level from one engine. generally he finds his 2 rotor in excellent condition when he takes it down after lots of runs...

talking real world, as long as you don't run over 600 i believe that reliability is probably similar to a 600 20b running on pump. all thanks to AI.

for those just learning about AI we do have a section with lots of basic info.

howard coleman

zinx 02-14-08 09:44 AM

intake temps under 32 degree F? What is ambient?

I don't run my car in these cold temps, but i remember looking back through logs and it would drop my air intakes 30-35 degree F once the meth kicked in, from 100-105 sitting in the line to 70 after the burnout.

silverTRD 02-14-08 11:11 AM

^thats amazing in itself^

zinx 02-14-08 11:36 AM


Originally Posted by silverTRD (Post 7866584)
^thats amazing in itself^


Yeah, meth is some cool stuff. My intake manifold was cold to the touch after a dyno pull.

ArmenMAxx 02-14-08 03:24 PM

Is it necessary to TUNE for water injection? Im thinking of tunning 16psi then just add small amount of waterinjection as a safeguard..

Good or bad idea?

slo 02-14-08 03:45 PM

I'm finding the same thing, with no inter cooler, it drops the intake temps to about ambient or slightly below.

At some point there is a limit where the charge can't get any cooler from meth, and the liquid meth is going to start cooling the manifolds and will be going into the engine as droplets instead of vapor. At that point your injecting too much meth as an AI system.



Originally Posted by zinx (Post 7866173)
intake temps under 32 degree F? What is ambient?

I don't run my car in these cold temps, but i remember looking back through logs and it would drop my air intakes 30-35 degree F once the meth kicked in, from 100-105 sitting in the line to 70 after the burnout.


ArmenMAxx 02-14-08 07:40 PM


Originally Posted by gmonsen (Post 7868440)
ArmenMAxx... What you're planning to do sounds just right. If you are using a standalone WI unit that let's you set to boost, you probably might want to try turning it on around 12 psi or so. Then, whether through different injectors or under PWM control, you want to be sure the amount of water you are adding is right. As you probably know, you want to avoid washing the chambers with too much. With WI even a little goes a long way to cool things down. The AI section probably has threads on choosing injectors and other settings.

Gordon

Exactly what i had in mind Gordon. I was planning on injecting VERY little water after 10psi. Im not planning on making a shit load of power with an aggresive tune with the AI yet, just have it as a safe guard for 16psi w/BNRs and flunctuating air-temp levels. Its either too cold and there is possibility of running lean or air temp is too high which makes it vulnerable to detonation. i dont want to worry about that anymore.

The trick now i guess is to find the correct AI unit and someone who knows how to tune/work/install it.

t-von 02-14-08 08:34 PM


Originally Posted by howard coleman (Post 7850997)

it is also possible to totally screw up the front geometry.

hc

Every true but it depends on how you build it. ;) When mine is done, it will have and even lower center of gravity than the stock set-up.

t-von 02-14-08 08:54 PM


Originally Posted by 1.3Ldreamcar (Post 7855927)
From an engineering standpoint a 20B that is streetable, smogable, and quiet wouldn't make 375..hp

Please elaborate on your assumption as to why it could not.



in fact I would have doubts that it could even make the 255 that the 13BREW was so widley acclaimed for making. Not to mention the marketability of "twin turbo". and lets not forget the weight distribution of the engine bay with a 13BREW as compared with the much longer 20B.

I'm sorry you don't know what your talking about.

t-von 02-14-08 09:05 PM

Let me clear up some more missconceptions. Doubters want to bring up emissions and such. Just because a 20b has 50% more displacement doesn't mean it can't make more power while still being emissions compliant. If that where the case a 4 cyl piston engine would have lower emissions than a v8. In todays time that isn't the case. It's all in how you engineer your emissions components to accomidate the increased displacement. Last I checked a BMW 325i and 545i equally pass the same emissions testing. Lastly a NA 20b would weight less than a 13b with turbo's.

t-von 02-14-08 09:26 PM


Originally Posted by howard coleman (Post 7865858)
"A 13B @ 23psi on AI has NO WHERE NEAR the reliability of a 20B @ 16psi NO AI."

i am going to respectfully disagree w the "NO WHERE NEAR " part of your statement. if you were talking heads up between the 13b and 20b BOTH W AI them i would of course agree that there would be somewhat of a reliability advantage. i am not contending the 13b/AI would be superior to the 20b/Pump w re to durability, only that it would be not materially different.

you have the 20b on pump. it would be making 600. the 13b on pump and methanol would be making 600.

if tuned correctly the 13b will run fine at that level with approx 25% of the pump removed and replaced w methanol. intake temperatures will be under 32 degrees F and knock will be less than 10 on a PFC.

gasoline autoignites at 660 F

methanol autoignites at 858F

that said, there is a point w the 13B where the crank starts to bend due to the torque produced and the lack of a center main bearing. this point isn't much further than 600 rwhp. the shaft bending is probably the engine's limiting point given proper fuel (AI) and tuning.

of course you can install a center bearing, lose the pump and make 1000 rwhp w a 13b. my friend runs in the middle 7s w his and has gotten over 20+ runs at that power level from one engine. generally he finds his 2 rotor in excellent condition when he takes it down after lots of runs...

talking real world, as long as you don't run over 600 i believe that reliability is probably similar to a 600 20b running on pump. all thanks to AI.

for those just learning about AI we do have a section with lots of basic info.

howard coleman


Very good points Howard.

2007 ZX-10R 02-16-08 11:22 AM


Originally Posted by howard coleman (Post 7865858)
"A 13B @ 23psi on AI has NO WHERE NEAR the reliability of a 20B @ 16psi NO AI."

i am going to respectfully disagree w the "NO WHERE NEAR " part of your statement. if you were talking heads up between the 13b and 20b BOTH W AI them i would of course agree that there would be somewhat of a reliability advantage. i am not contending the 13b/AI would be superior to the 20b/Pump w re to durability, only that it would be not materially different.

you have the 20b on pump. it would be making 600. the 13b on pump and methanol would be making 600.

the issue that hasn't been raised here is, what is the total out-of-pocket cost for either upgrade? sure, bolting on an alky system may be relatively cheap, but how about the host of other mods needed to support 600 freaking horsepower? how much money has Brian Cain gone through playing with alky systems? the stock drivetrain would break in half

600 hp is expensive business, either route

ErnieT 02-16-08 03:28 PM

With 600hp your drivetrain is fine, especially on the street. When your torque goes over the 500lb mark is when you need to start to worry, lol... The Torque is what breaks things and if your not launching the car from a dead stop at 9000rpms and droppin the hammer, your fine with even more power.

GoodfellaFD3S 02-16-08 05:59 PM


Originally Posted by ArmenMAxx (Post 7867558)
Is it necessary to TUNE for water injection? Im thinking of tunning 16psi then just add small amount of waterinjection as a safeguard..

Good or bad idea?

I've been running an Aquamist 1s system for years with the 0.9mm nozzle, I have it set to come on after 10 psi. Works like a charm, the car likes running at mid 11s AFR (at the richest) with the water injection on.....I'm injecting windshield wiper fluid from the factory w/w reservoir.

ArmenMAxx 02-16-08 08:30 PM


Originally Posted by GoodfellaFD3S (Post 7874933)
I've been running an Aquamist 1s system for years with the 0.9mm nozzle, I have it set to come on after 10 psi. Works like a charm, the car likes running at mid 11s AFR (at the richest) with the water injection on.....I'm injecting windshield wiper fluid from the factory w/w reservoir.


So if i was to use a smaller nozzle could i tune for low 11's afr? I want the car to still run "safley" if i dont use afi temporarily.

Is it ok to use windshield fluid?? lol

GoodfellaFD3S 02-16-08 08:47 PM

w/w fluid is ~80% water, ~20% meth, and a lil bit of coolant. I've been thinking of switching to a 50/50 mix though.....

The whole point of the water inj is to allow you to safely run higher AFRs, if it does fail you still should be safe at mid 11s with moderate timing and boost less than 17 or so.

MAXX65 03-04-08 02:34 PM

So this thread has convinced be to go AI as my next big performace upgrade.

So what kind of milage are people seeing from their tanks. I've been told by my friend that ownes a shop that most tanks are 2-3 gallons. I would be setting mine to be used under boost only, so I figure that it should last pretty long as a daily driver.

I have search the internet for refills to get idea of the cost, but I seem to only find the install kit.

does anyone have some $$$ numbers they can through at me of the usage cost?

Thanks

RedX7 03-04-08 03:26 PM


Originally Posted by MAXX65 (Post 7939342)
So this thread has convinced be to go AI as my next big performace upgrade.



Thanks

+1 My best friend has a 420whp S2000. I need something to get me over 450 safely.

BDC 03-17-08 01:59 AM

Heh, heh, heh. Even still, although they're well-meaning, people are skeptical about this.

Howard is spot-on. Alcohol is it. I hope more come to this same realization. Call me a zealot. Just don't go into it with the budget frame-of-mind in wanting to do it the Home Depot way because it won't jive. The thing that's honestly needed, alongside the use of a standalone, is a progressive system that can be adjusted according to load most importantly. It's the 3rd month into 2008 and this miracle of alcohol still has yet to be fully realized by the breadth of the community.

I really need to put my new clutch disc in so I can start loading out my car past 10psi of boost. I've got the 9yr old clutch disc slippy blues. Once it's done, I'm going to the moon with boost.. and yes, still with the stock top-mounted intercooler until it explodes.

B

galognu 03-17-08 07:02 AM


Originally Posted by BDC (Post 7986148)
Heh, heh, heh. Even still, although they're well-meaning, people are skeptical about this.

Howard is spot-on. Alcohol is it. I hope more come to this same realization. Call me a zealot. Just don't go into it with the budget frame-of-mind in wanting to do it the Home Depot way because it won't jive. The thing that's honestly needed, alongside the use of a standalone, is a progressive system that can be adjusted according to load most importantly. It's the 3rd month into 2008 and this miracle of alcohol still has yet to be fully realized by the breadth of the community.

I really need to put my new clutch disc in so I can start loading out my car past 10psi of boost. I've got the 9yr old clutch disc slippy blues. Once it's done, I'm going to the moon with boost.. and yes, still with the stock top-mounted intercooler until it explodes.

B


Brian,

What do you think is the best adjustable progressive system out there now?? Also, will any standalone do OK? PFC??

Thanks


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