There is one problem with E85, its got a lower energy content than regular gas and therefore must have a richer a/f mix to run the same. This means you will also get much worse fuel efficiency. I guess for someone running 500hp wouldn't be too concerned about fuel economy and E85 has major benefits over standard E10 or straight gas. For an NA rotary, even E10 (10% ethanol content) has an effect on how the engine runs, in a negative way. I know my 79 doesnt particularly like E10 and i will get about 20-30km less out of a full tank. Yes even that small amount of ethanol makes a difference.

 

You need to run 30% more then gasoline to make the same power but it burns cooler and has a higher octane rating so you can run more timing and a lot more boost. It's the poor mans race fuel.

thewird

 

From this thread https://www.rx7club.com/time-slips-dyno-128/pump-gas-502-rwhp-1000747/
Interesting! Right turbo, right setup I guess.

 

If you want to run 18 psi on 91, all the power to you.

thewird

 

I'm not sure it's a matter of "want to" as much as it is "can".

If everyone could run 18psi on 91 octane and make 500+hp reliably why wouldn't they? But they can't so we start seeing 94octane, race gas, water injection, meth injection etc etc etc.

I like the idea that 500+ hp is possible with gas I can get at any retailer, and without the added hassle of water or meth injection.

 

Like I said, its possible if your determined but I wouldn't use reliable in the same sentence. At the very least, I'd want to be using low compression rotors. The more efficient you make your setup, the less stressed it will need to be to achieve your goal so I'd look at the best porting option to do this which would be semi-pport. It runs and flows better then a bridgeport. You can setup up any motor to make some high numbers for X number of pulls and then blow up or lose compression from warped seals. I always think reliable, runs for years hp.

Refusing to use AI is silly in my opinion. It doesn't use that much and its free (water). The added security that comes from it and the fact that it keeps your rotors free of carbon, its stupid not to run it on any car even if you don't need it for the hp.

thewird

 

Not reliable? Setup for x number of pulls?

The engine in that car has seen plenty of pretty intense track time, multiple dyno runs (owner owns a dyno), and a ton of street miles I don't think it's reliability should ever be put into question lol.

From an engine standpoint I love the fact it's a bridgeported REW with all Mazda parts, no bullshit, that makes 500+ reliably on 91 pump gas with NO AI.

The fact of the matter is there are scrap yards full of rotors and housings donated by people trying to do what that car has done, it's impressive, there's got to be some secrets there in the tune and the components.

Do you have any plans on getting your car back on the dyno to get an "actual" max hp number?

 

It's not my car. The owner isn't even interested in dyno numbers, the only reason we even went to a dyno was because it was a new setup and it would be quicker to tune that way as you can't exactly drive it on the street. The only use the car is going to get is on the track.

Are you seriously questioning my dyno calculations using real conversions methods on one of the lowest reading dyno's out there when your posting an inflated Dynojet graph?

thewird

 

Sorry my mistake I was just about to edit my post.

Yes. At least the dynojet is a full run and not some "fuzzy" math calculations lol. "So I created a new dyno plot using the torque values estimated where they should be" Your words. Are you accusing the owner of that car and the dyno of "inflating" the numbers?

 

4+ years of track events on the same motor at 470 rwhp+ not reliable? The only incident I had was due to a boost line to the FPR rubbing through and I chipped a seal, no warparge at all in the seals.
And its not really about boost levels, its about power levels when it comes to fuel. If this car can sit on the dyno for 15 pulls plus over 15 minutes loaded against the eddy brake at full throttle for tuning, its not going to blow up anywhere else. What has more airflow across the cooling devices, the 3/4 hp dyno fans or being driven at speed? I didn't purchase a dyno just to take up space, I run all my cars on it hard on it, to make sure the tune is trackworthy. The temps on track are far lower than on the dyno.
Anytime you add another system, then depend on it, you are making the machine more prone to failure. If people tuned for their power level, on straight gas, then added water as insurance, sure its a safeguard, but depending on it for your power and building it into the primary tuning , is not the way to do it. I have already watched a brand name AI with failsafes go haywire on the dyno, I wouldn't trust that junk as far as I could throw it. Then there is the question of is the flowrate consistent during acceleration, what happens at lower tank levels with slosh, how much does battery voltage affect the AI etc etc. Just more to go wrong.
As for clean rotors, just run a good quality premix , even with the OMP running, they still stay clean.
As for they Dynojet, its the only "non adjustable" dyno on the market..

 

Its the correct way to convert it. The torque on the dyno is correct, just the RPM isn't, by correcting the RPM, the horsepower is now correct based on torque values. If you think thats fuzzy or fake, I don't know what to tell you.

The dyno operator actually gave me the dynojet dyno graph which was a 469 rwhp and after correcting for RPM, it would be ~550 rwhp but I used the original dyno dynamics one.

Anyway... the only reason I started this thread was because I thought members would be interested in what Jimmy is doing to represent the rotary at the track. Not really to start a discussion about dyno numbers >_>

thewird

 

He can't give you a dynojet graph unless he is using a dynojet period. I have had comparisons with other supposed low reading dyno's be plus 50, minus 50 and then within 1.. The only thing that is consistent to a dynojet, is another dynojet.
If the can't get a correct rpm of the dyno, I wouldn't put a lot of trust in the torque either.

 

Any time the dyno does not record a full pull, and you then pull out a calculator to whip some numbers up I consider it "fuzzy" if you don't then I don't know what to tell YOU.

I asked a question about what was possible. You told me the "short answer was no" I showed you an example that proved you wrong, you then got defensive and had to place all these caveats on the scenario, It's not reliable, there's a better way to do it etc etc. When you should have just said "Oh well I'm not capable of doing that, I've never seen it, I'm not sure how'd you do it, but good on that guy for pushing the limits successfully".

 

You know, years ago I posted a friends pump gas 619 rwhp T51 SPL pull and everyone just **** all over it instead of asking how it was done.

 

I knew there was a reason I avoided this forum for so long! Just a wasteland of old information, misinformation, and stubborn ego's.

 

Same, nothing has changed here...

 

Time to disappear again me thinks.

Alright rx7club, as you were.

 

Your completely right but I've seen the dynojet difference first hand. Had a car make 330 rwhp and within an hour drive 2 blocks down the road to a dynojet and make 374 rwhp with nothing done to the car.

All I can say to that is LOL. I have no interest in being defensive at all. I was posting assuming you were genuinely asking and was suggesting a better way to go about it where you would have to push the motor less. I just do that naturally since local members are always asking me for advice on their setups.

I'm sure Maxthe7man has a nice car and its fast but at the end of the day, its just another bridge with a big turbo making big top-end power. Its been done over 10 years ago, its nothing new. Neither is Jimmy's car, its just another bridge with a medium turbo for midrange, again nothing new or special. This is a whole lot more interesting on a 35R and half-bridge @ 16 PSi...

http://i254.photobucket.com/albums/h...hp13b-re-w.jpg

I don't understand where all this back and forth is coming from. Who is questioning who on what? I will never tune someone else's car at more then ~16 PSi on straight pump even if they ask me to. Before I got my water injection a few years ago, I used to run my own car at 18 PSi on the track but the water allows you run it so much harder with a huge margin of reliability. I just don't trust other owners to pay attention to their gauges to push them to those edges. So again I repeat, if you want to run 18 psi on 91, all the power to you and I hope it works out for you.

I do this as a hobby and have zero commercial interest. It makes me happy when owners are happy and I go out of my way to make a car run right and is setup properly, which they never are when dropped off for tuning. I've never cared about the numbers, only that the car is tuned correctly and runs right so this whole argument is pretty funny to me tbh.

thewird

 

How can I say this? There is never really an "edge" if you know where the edge is and when people start saying psi limits it means nothing .. Again psi has really nothing to do with the fuel limitations, its combustion pressure which equates to power output, if you want to define a limit, talk in mass flow rates.
Last time I checked this forum wasn't exactly knee deep in 500rwhp straight pump gas cars, it is knee deep in AI cars though. Yeah my pump gas setup was done 10 years ago, not on this continent though.. Also comparing your dyno sheet, looks like the T51R is a pretty good midrange performer with top end to boot.
I think what TD07 and ninesixtytwo was getting at, is you can't post a dyno sheet with a whole bunch of caveats on it and then go hand calcing ****, it just has no credibility, especially when the rpm is not even registering right, then go questioning other dyno's with half represented information. You'd be better off to go back and ask for them to synch the rpm properly, as you don't even have an accurate graph to reference your own tuning off of. I wouldnt even charge for the dyno time if my dyno pulled something like that. Its easy to say well what if this and what if that, and if this happened and I did that, guessing doesn't help anyone.
There are plenty of instances of power going both ways between dyno's, on the double rollers, even the strapping method and drive direction will affect the power.

 

PSi is the easiest way to put a limit on it that people will understand and 16 PSi is where I prefer to run cars running on straight pump. I've occasionally tuned a few cars further that I see have been modded well for cooling and a reliable fuel system but generally I won't go higher then 16. I prefer EGT's over a dyno's torque curve personally but that is just me. Both are obviously preferred. I expect every tuner to have their own way to go about it.

Maybe your right, there are too many caveats. I guess I'm just being stubborn because I know they are there but I still think its accurate. I did ask the shop owner if he could correct for the RPM after the fact but he said no. I didn't really care during tuning since I was just looking at the torque curve and my own logs for data. I'll probably be renting out my own little space and getting a dyno within the next year as I'm getting ridiculously backlogged lately. So when I have my own dyno, I'll be able to control the environment better so there won't be anymore caveats ^_^. Planning to get a Dynapack, I tuned on one and its my all time favorite dyno. Extremely consistent and wheel slip/RPM is a non-issue.

thewird

 

 

 

Thanks for the contribution! And proving his point!

 

I saw this
http://www.efi101.com/forum/viewtopi...5451d1f30631c9

 

Thanks! Its not the model I was looking at but if the price is right, I'll jump the gun. I've sent him a PM.

thewird