YoshiFD3S

iTrader: (19)

Gentlemen,


Long story short, due to an unfortunate incident this weekend with some bad/old gas, my motor is blown and has me left with many questions as to which direction to take at this point. I really do love rotary engines, and although I have dreams of a 600rwhp 2JZ-powered FD, the costs involved really aren't realistic for me right now. I am going on deployment in early 2011, and I would like to have my car running and shipped to me in San Diego by the summer so that I can at least enjoy it for a few months before I'm gone.

My goal is to make a reliable 450rwhp @ 18-20psi. I run a 62-1 turbo, along with all of the other standard air/fuel/ignition/PFC modifications that should support that goal.

So among my many questions is this: Should I go with ANOTHER low-mileage motor, or with a mildly street-ported motor with stronger seals, etc.

Would a STOCK motor running Aux Injection even be capable of handling my ~450rwhp goal, or do I NEED a built motor? In April of '09, I made 337rwhp @ 15psi on a Mustang dyno, running 93 gas on my now-blown "low-mileage JDM motor", producing one of the smoothest hp/tq/AFR/boost dyno graphs I've ever seen:



At this point I have decided to go with a water/methanol injection kit to help me obtain my HP goal SAFELY and as reliably as a rotary can really be...AI seems to be the past, present, and future to obtaining that 400+hp so many of us strive for, reliably.

While surfing some of the Howard Coleman AI-specific threads, I came across this Youtube video feature the AEM water/meth kit.

http://www.youtube.com/watch?v=W144mgUDySI

For a cost-friendly ~$350, it would seem the kit is fairly user-friendly, in regards to installation and would appear to only require some dyno time..

Does anyone have any experience with this particular kit, and can provide me with some feedback? Right now it is my #1 choice for my application.

So again, my goal is to make ~450rwhp @whatever boost levels the motor will safely handle while running a water/meth injection kit.

I greatly appreciate all suggestions, criticism and recommendations. I will of course continue to do my own research.



Thanks gents,

Yoshi

The Shaolin

iTrader: (5)

It sounds like you've already made up your mind. Why did the last engine blow?

Instead of buying a JDM engine this time around, send your blown one out to of the builders and have them assemble something for you. It may cost a little more to do things right, but it will be worth it in the long run.

Give the rotary a one more legitimate shot before switching to pistons

XLR8

iTrader: (52)

I agree. Jspec engines provide no guarantee's... With a proper rebuild, at least you know your bases will be covered. A good SP will also help your spool time, & achieve your power goals at lower boost. If your having the engine built, I would also have it ported.

Your power goals are very similar to mine. Though I will be using a 35R, these goals should be attainable with a 62-1 & a ported engine. Ironically, I too am going with the AEM water injection kit. Though I have no personal experience, I have heard good things, and like the additional features.

The two things I would strongly recommend is building a quality fuel system, & bumping your ignition output with a Twinpower. As we all know, rotaries don't like lean or break-up. I will be going with 850 primaries, 1600 secondaries, & twin supra pumps. Though this may be overkill, it is always a good thing and I know fuel will never be an issue.

With the ignition, you will begin to experience breakup with your desired power on the stock system. An HKS Twinpower will take care of this. It's been highly used by FD guys with great success.

On a side note, watch out for bad gas. I keep a case of octane booster in my garage for every fill-up. Some call me crazy, but it can help keep things at norm if you run into an occasional limp tank. My FD isn't driven everyday, so it may not be practical for you, but I would recommend it. I always worry about getting bad gas, and will be even more paranoid once I get my single build complete.

Take care OP

JDK

iTrader: (8)

Seek out a good tuner after all your mods are complete, your AFR's were a little lean.....13.5 is crazy

HardHitter

iTrader: (4)

As stated above Howard is very knowledgeable, I am in a middle of doing the motor pull and he is helping me whenever I come up with any problems. Great guy!

If you read some of his other threads, you need to see that rotaries are very sensitive to HEAT. Doing everything and anything to reduce the heat is what I am doing. I am ceramic coating EVERYTHING I can in the engine bay, having a turbo blanket, and to help even more, I have a trunk mount Aquamist water/meth injection kit, but I will just be running 100% water. Not only does it keep your intake temps down, but it also helps clean your engine. I have a 500R turbo and although I've been told it's capable of producing air flow for 550rwhp, I am only going to want a conservative 400rwhp on pump so it is RELIABLE.

Also, like stated above, eliminating heat and TUNE is what's going to keep your car safe. 13.5 Air/Fuel Ratio at WOT is pushing too lean in my opinion. Who did the tuning for your car?

I rather go overkill with keeping the car and engine safe, then be sorry later down the line.

Good luck on your build!

thewird

iTrader: (8)

The 13.5 AFR is a spike from when the turbo is still spooling. However, once you reach stable "full" boost, your in the 11.5+ AFR zone at close to 16 PSi. Assuming those AFR readings are correct, you should find a new tuner for your new engine.

thewird

GoodfellaFD3S

iTrader: (213)

you aren't going to make 450 rwhp 'reliably' out of a boosted 1.3L rotary without:

(1) water/meth injection, or

(2) race gas.

Sorry to hear about the broken engine. IIRC, you and your brother tuned it, correct? Do you have an EGT gauge?

Edit: How old was the gas?

bc_fd3s

iTrader: (2)

I agree with thewird...

I don`t think the engine was your problem.

thewird

iTrader: (8)

On another note, thats a lot of power your looking for. But since your single, it is possible although I don't think a JDM engine will cut it. You'll need a street ported motor for sure and AI injection to run that high boost. What does the 62-1 turbo compare too?

thewird

Howard Coleman

iTrader: (6)

it is possible to have a 400-500+ hp rotary that is reliable.

the fundamental challenge is our motors are only 159 cubic inches or 2.6 liters. so even if you are making 337 rear wheel hp you are 387 at the flywheel which is 2.43 hp per cubic inch.

if you look at the AMG Mercedes SL65 ($304,000) twin turbo V-12... titanium everything in the motor... they could have cranked the boost to the moon but they stopped at 661 hp from 365cubic inches. that's 1.81 hp per cubic inch!

you are making 2.43 at 337 rwhp.

so even at 337, everything has to be right. if ONE system or tuning parameter is wrong your engine is toast.

i can't emphasize enough that our motors are in a high state of tune. lots of Combustion Chamber Pressure.

and it is easy to deal with if you have the right systems and tune. the motor won't blow if it is properly supported and tuned.

the path to success is threefold:

start w a properly built motor. most motors i disassemble, including "low" mileage JDM motors need to be rebuilt.

support it w the right subsystems

tune it using knock and pre-turbo egt

then go out and blow off everything on the road.

a properly fixtured FD will make 400 rwhp at 5500 and be a street rocket.

your turbo will make 63 pounds per minute at 19 psi and is not a bad turbo. max hp should be 470.

good luck,

howard

thewird

iTrader: (8)

Leave it to Howard to bring out the numbers ^_^

thewird

YoshiFD3S

iTrader: (19)

Wow, I'm speechless at the replies thus far!

Here's some new updates.

The gas in the car was from September. The car had not been driven since. I am home on Leave in Georgia till Wednesday, and I had been casually driving the car to burn up the old gas. When I got to E, I put in roughly 5 gallons of 93 premium, to eventually also be burned up, to make room for my eventual 90/91 octane tune, for when I finally ship the car to San Diego where I am stationed. I was running out of gas on a drive home from a friend's house, and I didn't want to have to burn up a FULL tank of premium, only ~12 hours away from my scheduled 90/91 octane tune. I just wanted enough gas to get home from where I was.

After refueling I went WOT in part of 3rd and 4th on the highway, and that's when it happened. I believe it may have been due to the colder-than-usual weather here in GA, that my car was running TOO lean. I suggest this theory because in April, during warmer weather, it was running great. This is my theory at least. I'm sure there was a little left over bad gas too....and that probably didn't help. Live and learn, right?

As far as supporting mods, I already have 850cc primaries, 1600cc secondaries, HKS Twin Power ignition, PFC with commander and datalogit, Aeromotive FPR, and I believe a Walboro 255lph fuel pump, Am I perhaps missing something?

I am definitely no wizz when it comes to AFR's, but some of your comments have me interested and concerned regarding my posted dyno graph.

The tuner was Roy, who I believe is Mr. Grimes son who owns my brother's shop's property at Grimes, the renowned motor-building/modifying shop.

I can only trust your opinions that the 13.5 is considerably lean, however, based on the dyno chart, it would at least APPEAR that it had no direct effect on HP/TQ..however, as far as Knock and EGT's...I do not know enough to argue the effects of such a lean AFR. However, I am confident that my Knock was well-within reason, based on the number of experienced people who have driven my car, or rode in it.

I currently do NOT have an EGT gauge, and will admit my ignorance as to what is considered a "good" or "safe" EGT. Perhaps someone could enlighten me with a quick reply, or link to a thread?

Currently, I am looking at purchasing this motor:

https://www.rx7club.com/3rd-generation-rx-7-1993-2002-parts-99/long-block-engine-transmission-mods-ready-drop-878129/

With the addition of the AEM Meth/Water injection kit, does this seem like the answer I am looking for, to obtain my power goals?

Thanks again to everyone for your interest, criticism, and support.

I am committed to staying rotary.

:]

thewird

iTrader: (8)

I wouldn't be worried about the 13.5 as much as I would be worried about the AFR during the full boost run. Wideband sensors for dyno's are usually put on the back where they pick up air and at low flow rates, they tend to read lean or not at all until your actually on it.

thewird

Blackadde///

iTrader: (27)

LSX.... if my rotary blows after this build... that's what I'm doing.
Obviously, I'm not a purest. Enjoy the car, or else what's the point having it?

GoodfellaFD3S

iTrader: (213)

How exactly is this post helping him? What's your point ?

Yoshi, my peak EGTs tend to be less than 1400 degrees F. my probe is located approx 3 inches post-turbine in the DP.

also, that puny walbro pump is not enough to support your power goals by itself. look into dual pumps, or an Apexi' BNR pump.

YoshiFD3S

iTrader: (19)

IIRC, their wideband sensor plugs into here on my DP:

Blackadde///

iTrader: (27)

Was I supposed to read the whole thing? whoops... i saw the word "reliable" somewhere.

j/k j/k We all know adding AI to our motors drastically improves their reliability.

But my point was ....that a lot, if not all, LSX fd owners love the reduced maintenance, reliability (not saying rotaries aren't reliable) and N/A power potential of lsx motors. I don't know how some of you stay with the rotary after 4+ rebuilds. We're all not as fortunate as some to be able to rebuild our own motors Rich.

YoshiFD3S

iTrader: (19)

With all due respect, MotoTek...nowhere in this thread am I even considering the idea of going LSX.....I don't doubt or argue the LSX's reliably, power, etc...but you're going off-topic.

All things considered, thank you for your input.

jamespond24

iTrader: (13)

I see LSX motor blow up too so what's your point? Just get the motor built with right seals and a good tune is all he need.

YoshiFD3S

iTrader: (19)

In a conversation with a friend who made ~715AWHP in an Evo and did his own AEM EMS tuning, he commented on my 13.5 AFR during initial spool up.

He suggested that tuners often Lean out a motor during initial boost, to help provide a quicker spool. He couldn't explain the science behind it, but considering his experience, it seems like a reasonable explanation.

If you look at the dyno, my AFR's steady out at roughly 11.5...My tuner has dyno-tuned cars making 1,500+hp....I trust his methods.

Enough on that.

Here's another question for you guys.

I just recently received a PM from a Member suggestiong that Atkins and OEM seals are not good. He recommended ALS or RA Super Seals.

Can I get some input on that?

Howard Coleman

iTrader: (6)

"suggesting that Atkins and OEM seals are not good."

that is ridiculous.

djseven

iTrader: (56)

I have torn down engines with every seal imaginable other than NRS ceramics, and the fact remains the RA and ALS seals are a whole lot more forgiving than OEM or Atkins. I would love to build all my customers engines with Atkins seals as they give me great prices(shout out to AtkinsRotary.com). However, how often does the average fd owner spend the time and money to do things 100% correctly? Not very often, and even if they do, on a heavily modified fd, one small thing can cause an engine failure. Just makes sense to use the RA or ALS seals in my opinion for the piece of mind. The RA seals are a little more aggressive on the housings, the ALS I am yet to see any torn down with 20k plus miles so I will hold judgement on that.

For a fd with DP and Catback and reliability mods, the Atkins and OEM seals are great. For the rest of the FD crowd which generally consists of guys in there early to mid 20s wanting lots of horsepower on a budget the ALS and RA seals are a great decision.

Monsterbox

iTrader: (6)

I too thought it was safe to run a higher afr at lower rpms...once the car is in full boost and power band then you need to lower it to below 11.5.

I'm still on twins...I run around 12-13afr below the transition...then once the second turbo kicks in it immediately drops to 11.2-5.

no_more_rice

Go with OEM 3 mm. you won't regret it. They withstand more abuse than 2 mm, based on first hand experience.

Howard Coleman

iTrader: (6)

the only subject that inspires more typing accompanied by less actual knowledge than apex seals is oil.

FYI, i ran Atkins apex seals in my personal 507 SAE hp motor for four years 14,000 miles and over 120 4th gear 2000-8000 dyno pulls.

last spring my curiosity got the better of me and even though it was still gaining compression i pulled the motor purely to analise it.

the seals were perfect, still straight, no flatted leading edge. the housings had absolutely no chatter marks or carbon on them.

my bottom line is if you build the motor right, run the correct systems and tune it right any of the apex seals will work just fine.

i have nothing against ALS, i have a set sitting on the table... i just take exception to anyone knocking Atkins or Mazda seals. my friend Jose LeDuc has often run mazda seals in his 1000 (that's not a typo) rwhp two rotor meth burning RX3. generally, when and if the motor needs to come apart it isn't the seals.

given my first hand experience over 4 year at the 500 hp level i would hardly say Atkins seals are just for someone w a catback and DP. i am running a bit more than that.

howard coleman