J-Rat

iTrader: (2)

I get 411 pound feet of torque.. Minus 17% loss equals 341 at the wheels, and I used your calculator.



Still somewhat a large gap between HP and Torque, but you said yourself, the timing was very conservative.

Thank you for clearing up the Octane number. Unfortunately our max octane here is 91, unless I go eight blocks away and get 100 octane (also at a pump). That kind of muddies the term "pump gas" in my opinion.

Please trust that I am NOT trying to pull you into any form of flame war, I am just trying to show the numbers in terms that are more prevalent to people in the US.


Have a SAFE and happy NEW YEARS!!!!!!

J-Rat

iTrader: (2)

Yeah, and those pesky steetports running alchy dont make much HP either...

MY theory is he is trying to put 24 pounds into a 5 pound bag (stock intercooler). Its my firm belief that he was WAY out of the efficiency range of the turbo because he had to overspin it to make the requisite power. He feels otherwise, and thats fine, but I would NEVER personally try 400+ hp on a stock IC...

Just my .02

RotaryEvolution

iTrader: (30)

i was thinking the same thing, the IC is going to be a major restriction but the IAT threw me since they appear reasonable and wouldn't be a major cause for concern unless the sensor being sprayed with alcohol is being misleading as to the true IAT the engine is seeing. over 400HP on the stock IC is an accomplishment if you ask me but i would have focused on seeing where the turbo itself was happy first before trying to push the whole setup for higher numbers.

when i did my dyno runs i found the turbo i am running is only efficient to a fraction of what i had hoped, pushing it further is just asking for trouble so start with a minimal boost level and begin staging it and seeing where your numbers peak out rather than trying to prove any naysayers wrong that high boost on pump is perfectly safe which it obviously is not but is also reliant on the setup on the engine and cooling.

i was much happier saying my engine put out X amount of power at 12PSI than pushing it up to 20PSI and saying it put out Xamount of power +2 additional HP because the turbo is being overworked and stressing the limits of the tune and setup.

the SMIC is probably the main reason for the late spooling of the turbo, i myself got tired of trying to push the limits of inadequate setups just to prove something to myself or other people. is it really worth pulling out a motor and having to rebuild it just to say i may this amount of HP on the SMIC? maybe once or even twice but after that it begins to be a real headache having your car in the shop more than your customers cars.

Boostn7

YES, you hit it dead on.....something wrong with his setup !!!

Your Ms observation is not enough to explain the severe knock he experienced.
That fact that he's re-tunning it over and over should have raised a flag showing that his auxiliary system not being consistent w/ its methanol delivery.

With severe knock there might be more damage inside.....only BDC will know.

JD

RotaryEvolution

iTrader: (30)

could be, i broke 2 irons and just replaced the rear irons solely and the engine runs perfectly fine still.

it could likely be an issue with the AI inconsistency, i have no issues with my Devil's kit being inconsistent so i didn't even think of that being a possible cause but i also only run 50% distilled water and 50% pure methanol so the dillution factor of actual fuel delivery is much less of an issue with my setup, going 100% methanol and relying on it to be always accurate can be a deadly combination unless it uses actual fuel injectors and reliable staging system.

Boostn7

?????? Yeh, must be the C16 race gas, alchy or 23psi!!!!!

TII intercoolers actually flow well but regarless, he was getting 24psi at the intake and with methanol injection taking care of inlet temps he's only issue is overspinning the turbo but still within acceptable efficiency.

I'm sure you use your alchy system to raise the knock level but some choose to use it as a fuel to run much higher boost thru a auxiliary system.

JD

AlexG13B

iTrader: (7)

karack are you removing fuel from your map?

RotaryEvolution

iTrader: (30)

yep, otherwise it would run a bit rich and lose overall power.


i don't see why the water guys have such a field day with trying to kick the alcohol guys when there is an issue. if i have another detonation issue at higher boost levels are the water guys going to come in here and gloat too?

J-Rat

iTrader: (2)

Yeah, thats why I can make 407 wheel with 13 PSI....

My 490 pull was DEFINATELY on race gas. Why? Because I dont XXX around above 20 PSI without race gas Alchohol, Water, or otherwise... I dont like building motors, and I am DAMN sure not going to risk my motor to prove which injectant can get closer to the edge before allowing knock.. It isnt like race gas makes MORE power, in fact in lowers power (but you already knew that)...

Indeed, as far as my alchy system, you are correct. Its there to raise the knock threshold and cool the intake charge. Tucson summers are HELL on rotaries...

rotarygod

iTrader: (1)

Actually he also mentions that he may have been too agressive on his timing so it seems like he knows that it may have been his fault. Go read your own quote again.

That's not it at all. He has fully admitted that he's well outside the efficiency range of his turbo and intercooler setup. He was mostly concerned with how far he could push it on this setup before he blew it up. I guess he found out! It was bound to happen someday. It has nothing to do with an auxiliary system. That can work fine. I'm sick of seeing people blow up their cars with conventional fuel systems and low boost levels. There's NO excuse for that!

The fact that there is a bridgeport or 24 psi of boost is actually irrelevant. A boost number is just that, a number. Boost pressure is not directly reflective of airflow as different turbos flow different amounts of air at different pressures. He's running a turbo that is outside of it's efficiency range. If he was running a turbo inside it's efficiency range, he'd have made more power. Don't make the all too common mistake of focusing solely on boost pressure. We see too many stupid irrelevant questions such as "How much boost pressure can I run?". It doesn't tell you everything and with that little information nothing relevant. Even worse still is someone will answer it with a number! The car that RR is talking about that made 580 hp probably has a more properly sized turbo on it for it's power level (looks like it!) and the intercooler is definitely large enough. Those 2 things can make all the difference in the world with efficiency and risk of detonation. He has lots more room to go before hitting the edge and can probably get higher numbers as a result of the greater efficiency. No surpise here.

I for one am highly impressed with the numbers Brian put down with that turbo and intercooler. No one else could do that with the same equipment! You need to go laugh at the people who blow up their cars at 300 HP from nothing more than bad tuning. We see it all the time! There are far more of those here there are pioneers at pushing the edge. Cut Brian some slack. Unlike many rotary people, he shares what he does with others in the hope of bettering a community which sorely needs more people who know anything useful. He's within that 1% who isn't scared to share what he's done. He is very open and helpful. He's creative and he's willing to push the limits and even risk blowing it up all in the name of learning. Show me someone else on the forum that is willing to do what Brian does and then tell every detail about it. I'll wait.

Nice effort Brian! Get it rebuilt with a new turbo and intercooler and come back bigger and better than before and show everyone how far they can push things with everything designed around it.

There are advantages and disadvantages to both water and methanol injection. Neither is perfect and both are supplements. Of course you can make an engine run solely on methanol if you desired! I find it funny that someone would insult one over the other. You can easily find fault with each approach and positives to both. Which one is better? Who knows? They can both obviously work well and that is the whole point. Just slightly different approaches to it. It's not worth insulting one over the other. That's a futile excuse to justify the other one.

rotarygod

iTrader: (1)

Going back and reading his update again, he is fully aware that he made some timing errors in his excitement and doesn't seem to blame his issues on bad gas. He merely mentions it as a possibility but in no ways is blaming it. He also didn't blow the engine up internally. He was using S4 housings and cracked the rear one at the dowel. Surprised? We see this happen all the time at far less power levels than he was putting down. I don't see what was so surprising about any of this or how in any way it was related to his injection. He admits ping but again also admits a timing error on his part. At high power levels, it doesn't take a big mistake to cause a bad outcome. He's in good spirits about it and even mentioned that he was curious to see that that turbo could so and now he knows. Time to move on to the T70. It sounds like a normal learning curve to me.

J-Rat

iTrader: (2)

The fact is, Brian can have the motor out, fixed, and back to running in a day. That man is sitting on PILES of parts. He will be back up and running in NO time.

No_Rotor_RX7

as i said in BDC's thread on teamfc3s... he had done many many pulls on the street and it was setup to handle what he was throwing at it just fine. i am thinking that the dyno changed the load enough to where it threw off his tune. he said he noticed the afr's he tuned for were different.

this is why we only tune on mustang dyno's. dynojets are the lose

BNA_ELLIS

I remember you posted a few weeks ago he was havings stuttering issues under load. I suggested you run colder plugs to prevent pre ignition, did you change them before hitting the dyno?
It's debatable whether an egt reading 3 inches from the turbo will react quick enough to tell you trouble is coming.

Howard Coleman

iTrader: (6)

the forum does not tolerate bad language. read the rules.

i am not a baby sitter. if you use bad language and i have to delete it the next time you use bad language i will delete your entire post.

howard coleman

BDC

Nope I didn't change them given the power output being below what's established as "safe" for use with BUR9EQ's all around. I did consider it as one possibility, but honestly the car wasn't on the dyno very long at all for it to really get mean and nasty hot. Infact, the manifolds were still room temperature after the blow-up run. I suppose it's possible that a plug may've caused it as the misfire I felt up high was reminiscent of what too hot a plug does. I've seen and felt it a few times in the past.

Unsure what to comment on about the EGT, but I am going to move the probe over to the collection point on the exhaust manifold during the down time. I'm really, really curious to see what the bonafiable difference is. Perhaps I'll write a thread on it later on.

B

Wargasm

Who was the first one to single turbo an FD?
Who was the first guy that wanted to try a bridge port (yeah there's a nutty idea)?
What about the first person to put a 20B in an FD or FC chassis (not counting Mazda)?
How about grinding ridges into rotor housing water passages to help cooling?
Someone was the first one to do non-sequential on the FD...
etc
etc

I wasn't the first to do any of those - I came way after and I followed in the proven footsteps of other folks. Most of the people on this forum don't really innovate or try new things... they copy what works. Nothin wrong with that

The point that I'm trying to make is that we all owe people like BDC and Howard our thanks for spending their time, money, and blood trying to do something a little different and sharing their experiences with us (the good and the bad). Their successes become our new potential paths... their failures become things that we all learn from and help us avoid going down the wrong path wasting our time and money.

We also owe our thanks to others who have shared their experience and offered help, I'm not saying that BDC and Howard are the only people on the forum doing this.

Anyhow, for the new year, I think there should be a group hug on the forum and everyone should just focus on having fun with these RX-7s we love, no matter how we make 'em BRAP!

GoodfellaFD3S

iTrader: (213)

^^^I agree 100%. Too often all over this forum there is rampant in-fighting amongst rotary owners, when we all *should* be sharing our knowledge to make some serious XX horsepower to crush all the piston-powered cars out there

frode

Hey dude! My wrong!

At 7500 rpm (max HP) I have 580bhp and 557nm of torque!
At 6400 rpm (max tq) I have 540bhp and 600nm of torque!

600nm equals 443ft-lb -17% makes 367ft-lb at the wheels. Better now?

Timing was conservative yes. It was the first rotary we tuned.

frode

We cut the input shaft on a audi quattro straight off once using a tilton tripple-disc :-)

frode

On my car I run a 4ch Autronic CDI, 4 x Crane Cams LX92 and NGK B11EGV in all the holes. No break up and no hard starting in the morning. Street driving is no problem with this setup.

Boostn7

OK, what's the point ?? no one else could???

13 or 14 psi ...congrats on the numbers.

JD

J-Rat

iTrader: (2)

I am with you.. I am out of here..

Boostn7

That fact that BDC limits himself to 14psi on 93 octane but then depends on an auxiliary system to dump methanol to fuel an extra ~12psi of boost makes no sense in my mind but its his choice.
When he starts to claim it be the cure to broken motors and push the idea for others to do the same then I will continue to post on here so people don't repeat his mistakes.

Auxiliary systems(water or methanol) when used properly to raise the knock level will allow a bit more boost and horsepower but not depend on it like a secondary EFI like BDC has been doing.

JD

BDC

How do you know this, John? Got any personal experience with it? I do; about 5 months of it under my belt so far including all the ups and downs, and I am more confident today than I was two days ago on the dyno that using alcohol like a secondary fuel system, in that capacity, does more than just "raise knock level to allow a bit more boost" -- it's a completely different beast altogether. It is a paradigm shift; an utter change of ideology in how we modify the car and ultimately how much boost and power we can make reliably.

The reason why I've chosen to limit myself as a tuner to 1bar of boost or lower on pump gas isn't a testament to poor tuning, lack of overall experience, or anything like that but it's more about the unreliability of pump gas alone as a fuel. In my opinion, which is the concluding evolution of several years of doing this stuff both professionally and as a hobbyist, is that pump gas is highly unreliable in and of itself. It is my strong feeling and has been for quite some time, long before I ever drempt of doing AI stuff, that the bar is and has set way too high for what this community expects to produce power-wise out of their Rx7's on pump gas alone and what they're led to believe is reliable and safe. We can talk to each other about this until we're both blue in the face, but that's my stance on it and it will not change unless there's a dramatic change in the quality of fuels available at the pump. The advent of using alcohol in the manner than Howard and I are doing it based upon the Alkycontrol system design all the sudden opens up a whole new way of running boost on pump gas when a good portion of the fuel in the charge is replaced with alcohol as opposed to just a sprinkle added which is indicative of the rest of the AI world, generally speaking. That's why we have such rich ratios of gasoline to alcohol -- 70/30 in my case and nearly 60/40 in Howard's case -- we're both convinced that the alcohol has a cumulatively beneficial effect on both power output and reliability. See, everyone's putting the microscope on my setup, dissecting each and every word I say into pieces, trying to find the holes and point the finger, yet most everyone has either ignored or forgotten about Howard's setup: He's running two M10gph @ 100psi nozzles at a nearly 60/40 ratio and, last he ran, was in the 7000rpm range at 23psi of boost out of a pair of T3/T04E-46 turbos, with 15*L advance with zero knock on his PowerFC datalogs. That's over 80lbs/min of airflow. The heavy alcohol ratios are enabling this great divide between what you've noted as my 14psi and under on pump gas alone thing vs. trying to hit stratospheric and rather insane boost levels with alcohol. For all intents and purposes, practically speaking and notwithstanding the technical differences between AI and race fuel, it's like the huge shift in how hard and how long the car can be run between using something like 93 octane pump fuel and VP Racing's C16 117 leaded race fuel, for example.

I hope this helps clears it up, John. If it doesn't, please let me know and I'll try to explain further or go over any points I may've missed.

B