The Interceptor-X for N/A Cars
It's most likely that once Scott posts the correct dyno graph, and we see his AFR, that there might be room to push the mixture leaner to about .92 - .93 lambda. Most likely Scott tuned swoope's car conservatively since it was not his. But I'll hold off any speculation until we see this graph.
Originally Posted by rotarygod
...I assume the engine isn't tuned on the ragged edge so you absolutely need to run higher octane. .... I have never been one to claim that higher octane would give you more power. People assume it does which is why I stated high octane might give you more power. Again it depends on how the car is tuned. ....
One thing I'd be interested to see is someone do a staightup comparison between the two units from a power curve perspective. Dyno charts showing 'under the curve' power not just peak HP would help to show whether the I-X has a tuning edge here. Peps are asking for full torque & A/F charts but they've not been produced yet, which would help even more.
As for my CZ Gold and tuning on the bleeding edge, well, I figure why not get all the power I can (for track use and esp. at constant higher RPMs), and if a couple bucks extra for higher octane fuel will do it...or a can or two of octane booster does the trick... so be it... if it actually works. That's what I'm emperically working to discover. The fuel maps in the CZ certainly help a lot for mid and high end grunt, and I'll be working the ignition maps next Spring to find any power left on the (bleeding) table, if it's there.
I'm still a bit confused whether you think more absolute power can be obtained with low or high octane fuel, emission/cost issues aside, and given 'proper' tuning. Do you believe 87 w/good tuning is equal to 93+ w/good tuning, or are you saying 87 works 'ok' and is the best value, and that whatever little extra isn't worth it (to you)? I guess I'm asking - have you done both so as to compare and dynoed them? Charts would be a great help if you had them. Thanks.
Last edited by Spin9k; Dec 15, 2005 at 12:52 PM.
Let me say that this low octane/low advance high octane/high advance debate has been going on between rotary engine builders and tuners for ever. I personally have known people using additives to lower the rating below 87. What I have not told you guys is that this was the second dyno session. Wed. afternoon was the 93 octane high timing tests. I advanced the timing up to 38 degrees at one point from 7-9k rpm and the motor hated it! It was not pinging but lost alot of power, I went in two degree increments up and down from 30 degrees, adjusted the split between 5 and 15 degrees. I also have the ability to vary the amount of fuel per pair of injectors and therfore can select and change the volume and how fuel enters the intake runners/ports. I still beat the Factory computer up top and through the midrange on 93 but was less than happy with the difference. So thursday we empied the tank and filled it with 87 and returned to the dyno. In the past when trying to build the worlds strongest stock 13B in the SCCA ITS class I found 87 made the more power than 93 and after last night I found the new motor likes it as well. Sure there is a 25 cent savings per gallon but that really has nothing to do with it, the engines produce less heat because of the lower timing, and therefor run better longer. The bottom line is this, I found better results using 87 octane. I have owned and been involved with high performance rotary powered cars since the late 80's. Maybe someone out there who has no history with how they work will come up with a whole new approach and look like a Rotary God with kerosine? What I have brought to the table is a plug and play increase in performance. The Interceptor-X is not a SuperAFC or a SuperAFC with a laptop interface. It is a full standalone in a plug and play configuration that will allow users to tune, yes really tune the ECU to their specific car,fuel and collection of components. Back to the shop,Scott
the results were exactly what I was expecting. All of us old CZ followers are familar. Now Scott has done a great job. The graph shows a good tune(as far as you can tell) that will be consistant(unlike the CZ). Also to all the under the curve power is where the action is and he has good gains there. A car with this powerband will pull the stock car on the track/strip or street. Good usable power. Now with a mild street port with the right header, high flow cat and cat back and the car tuned with scott's thingy you will see 225-235 horses on the concrete. The beat goes on and I am broke!
rotor on Scott---congrats
olddragger
rotor on Scott---congrats
olddragger
Oh by the way the rotor does like the slower burning fuel. Everyone does know( I KNOW some do)the rotor has a MUCH longer combusion/flame time than the recip---right?
olddragger
olddragger
really, i wouldn't have cared if there were no gains. right now the mods for the 8 are pretty standardized. if you have a turbo, it's more than likely the greddy and most NA mods are pretty similar in terms of power gains. so now we can expect to all see similar gains. i think the interceptor is just a stepping stone to larger projects for many of us, whether it be FI, porting, nitrous, mystery juice..whatever. once the aftermarket really opens up, the interceptor will prove invaluable as it can be adapted to work with anything as well as it works NA or with a bolt on turbo.
PnP gains are great, but like the canzoomer ended up being, that's not really what this is intended for.
PnP gains are great, but like the canzoomer ended up being, that's not really what this is intended for.
another idea Scott and guys. Everyone may really want to consider having sometype of additional ventilation in the ecu box. You may be surprised how hot it can get in there and those with the turbo's --well need I say more. For longitivity purposes please look at that. Temps outside are cool now but this summer is another matter. The factory ecu(within the ecu box) in the summer in ga on a n/a car will get so hot that you can hardly touch it without burning yourself.
OD
OD
Registered User
Joined: Jun 2002
Posts: 3,086
Likes: 1
From: Misinformation Director - Evolv Chicago
Did you mean the faster burning fuel? 87 is the faster burning fuel, which Scott just intimated was the better option in his findings...
Wow, 1000 posts and it only took me 3 1/2 years.
Wow, 1000 posts and it only took me 3 1/2 years.
very quick note.
the thing drives amazing overall, notably between 3.5k and 6k.
and the traction control was on a long time on the 1-2 which was shifter early.
beers
cool that this is my 1k post
the thing drives amazing overall, notably between 3.5k and 6k.
and the traction control was on a long time on the 1-2 which was shifter early.
beers
cool that this is my 1k post
AFR chart
Sorry for the delay with this chart. Somthing in the "save" process (somtimes happens with the dynojet)has distorted the data if I choose engine R.P.M. This pull was performed in fifth gear and full throttle was applied at ~2800rpm as indicated on the factory Tach. I have added the rpm as close as I can. There is no doubt with more time I could have made the AFR visually smoother, but the engine was not responding to the same AFR/timing across the RPM range. I feel confident there is more power still in the tune, not alot but a couple here and a couple there. Swoope was kind enough to help out and I have already done enough testing with the car. BTW A big Thanks to "Swoop" for stepping up and saying "if it will help the RX-8 community use my car" no strings attatched. If he had not stepped up the testing and results would not have happend this quickly,Scott
Last edited by MazsportScott; Dec 15, 2005 at 08:48 PM.
Originally Posted by dmp
Where do you see a 5-10% increase in power? After an email discussion with a close friend, he showed me how it's about 4rwhp, average over the entire rpm range, and averages about 11whp over the last 1/3 of the rpm range.
Originally Posted by brillo
thanks for the chart, why the dip in the afr around 4500? other than that, its flat as a board.
I think owning one is a must for N/A modified 8's, with a future path with a turbo. Why operate the stock OEM PCM if everything else is modifed? I'm sold, just have to get past the holidays.


