getting my LT10S RX7 dyno tuned next week. suggestions needed!
OK, SOOO Last year I bought an 87 TII drag car from a salvage yard. It was parted out and not running. It has been quite the project so far… I have the car set up with stock primaries, 720cc secondaries, a large hybrid turbo, stock ignition, and a front mount. I got the car running and driving on a microtech LT10s. It pulls ok, hesitates around 3k, and doesn’t like seeing boost. This is my first time working on a rotary and I’m pretty proud to have gotten this far, but I know I can’t tune this ecu by myself on the street.
I’m taking the car to flatout motorsports, a nearby shop that specializes in Miatas. My appointment is in a week. They have a dynapac 3000 that we will be using to hopefully get this thing running smoothly and making decent power. The dyno operator said he has never even heard of a microtech ecu... but he is willing to give tuning it a try. I’d like you microtech experts out there to look at my setup/maps and tell me if there is anything I should look for, pay attention to, change ahead of time, or any advice for me or the guy that is going to tune it. Thanks!!! Under options, should dwell be at 3.25, and should decel be set to off? I noticed the car doesn't decelerate very smoothly. idle Screen 1: 30" 1.24 25" 1.33 20" 1.57 15" 1.86 10" 2.48 05" 3.48 00" 4.33 Aux 02psi 4.76 Aux 04 - 20 psi 4.95 Load 30" .. 1.52 25" .. 1.48 20" .. 1.57 15" .. 1.86 10" .. 2.43 05" .. 3.29 00" .. 4.33 02psi .. 5.57 04psi .. 6.38 06psi .. 7.14 08psi .. 7.86 10psi .. 8.48 14psi .. 8.71 16psi .. 9 18psi .. 9.48 20psi .. 10.00 RPMwot 500 .. +00% 1000 .. +00% 1500 .. +00% 2000 .. +00% 2500 .. +00% 3000 .. +00% 3500 - 9000 .. +00% RPMcrs 0500 .. +00% 1000 .. +00% 1500 .. -00% 2000 - +00% 2500 -9000 .. +00% Pump Pump1 Amt 10 Pump1 Pulse +02 Pump 1 Trig + 14 Pump Stop 00" Pump 2 start 2000 Pump2 AMT +30% Pump 2 TIME +10 Pump 2 TRIG + 16 Pump 2 STOP 00" Pump 1 Adv 05+ Pump 2 Adv 05+ Pump Dwell 5.00 Pump Timers NO Pump 1 Sync NO Pump Spare +8 Pump Cold 00 Water 124 C .. +16% 99 C .. +11% 82 C .. +11% 68 C .. +15 % 60 C .. +20% 46 C .. +25% 38 C .. +29% 31 C .. +35 % 24 C .. +41% 18 C .. +46% 11 C .. +52% 05 C .. +58% -01 C .. +63% -09 C .. +68% -17 C .. +70% -25 C .. +00% air_t -25 C .. +00% -17 C .. +08% -09 C .. +06% -01 C .. +05% 05 C .. +05% 11 C .. +03% 18 C .. +02% 24 C .. +00% 31 C .. +00% 38 C .. +00% 46 C .. +00% 60 C .. +00% 68 C .. +00% 82 C .. +00% 99 C .. +00% 124 C .. +00% Crank -25 C .. 72% -17 C .. 72% -09 C .. 72% -01 C .. 53% 05 C .. 47% 11 C .. 44% 18 C .. 41% 24 C .. 38% 31 C .. 37% 38 C .. 34% 46 C .. 31% 60 C .. 28% 68 C .. 25% 82 C .. 22% 99 C .. 20% 124 C .. 19% t*rpm idle .. 00 1000 .. +10 1500 .. +15 2000 .. +20 2500 .. +23 3000 .. +24 3500 .. +25 4000 - 9000 .. +25 t*map idle .. 00 25"Hg .. +05 20"Hg .. +04 15"Hg .. +03 10"Hg .. +02 05"Hg .. +00 00"Hg .. +00 02psi .. -00 04psi .. -03 06psi .. -05 08psi .. -09 10psi .. -11 14psi .. -15 16psi .. -20 18psi .. -20 20psi .. -20 t air 0 C - 124C .. +00% t gap 0500 .. 15 1000 .. 15 1500 .. 15 2000 .. 14 2500 .. 12 3000 .. 10 3500 .. 10 4000 .. 9000 10 t*inj 0500 .. 120 1000 .. 150 1500 .. 150 2000 .. 150 2500 .. 150 3000 .. 180 3500 .. 180 4000 .. 180 4500 .. 210 5000 .. 210 5500 .. 210 6000 .. 240 6500 .. 240 7000 .. 270 8000 .. 270 9000 .. 270 t*wat -25 C - 124 C .. +00 Screen 29: RPM ON OFF MAP ON OFFF FAN ON OFF AUXFAN ADD .10 FANAIR .10 AUXAIRMIN 10.00 AIRMAX 10.52 AIRWAT .48 AIRafs .10 AUXRPM SET 0880 Pwm LOW .76 PwmHI 7.62 RPMlim OFF AIRadd .19 Enrich 0 Timing 0 Option Opt MIXtrim - 5% Opt TPScal +28% Opt TIMtrm - 00 Opt Static - 00 Opt TIM MAX 30 Opt RPM Wot 00" Opt rpmCRS 17" Opt Af_StE +10 Opt IGNlim OFF Opt REVCut 7500 Opt BOOSTCut 20psi Opt REVstg 3000 Opt MAPstg 02" Opt %stage 70% Decel OFF Dwell 3.25 Maps = Normal Config +04 Cyl/R Firing SEQUENTIAL LOAD = MAP Sensor DWELL = Time base Input Trig +POS Spark Trig MAZ+ Timing check OFF Rpm_ON 3500 Log Map_ON OFF Log Sample +00 Log Spare +00 Log SHIFT 7500 Dash WATER 99 C Dash Air_T OFF Dash BOOST OFF Dash |
oops double post
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The map looks pretty bad and id also be weary of getting a tuner with no microtech experience to set it up and you also need to know what rotary experience he has.
Fuel cuts should NEVER be used on a rotary as they will lead to engine death.The map atm has cuts so could blow on the dyno if the tuner doesnt know. Do some research and read the manual as they are one of the simplest ecu's but with a boosted rotary one mistake could end in tears. Its not all bad do a search for maps here based on injector sizes you will find something much better which the tuner will only have to adjust slightly.You will need some knowledge to determine if it looks ok or if you are still unsure use the base map stickied at the top.the car will then be safe and very rich which the tuner can then work on safely. |
Thanks. I have read the manual and looked at the "base maps" and many other maps posted. There is a ton of misinformation, conflicting information, and incomplete maps on this forum. It makes it tough to tell what is right and what is wrong. That's why I figured I would post mine. I know it's not the best map, but at least it got the car running and driving. Now it's time to work out any problems.
Thanks for the tip on fuel cuts. So you're saying I should change the revcut setting to like 9,000rpms? or is there a way to turn it off? and if so, what is preventing the engine from over-revving? Are there any other settings that cause fuel cut? I set boostcut to a level I knew I wouldn't exceed. |
my rpm cuts are set to 15,000 rpm because no way in hell it can ever be reached:lol:
The driver then becomes the rev limiter. The problem with killing fuel is this is the worst thing you can do to a boosted rotary IT WILL LEAD TO ENGINE DEATH whereas it seems to work ok on piston engines. An overrev or overboost are lesser evils than a fuel cut. The reason i said to try the base map is that in the manual about step 3 and 4 is to set the rpm crs and rpm wot.Your map has nothing there:icon_tdow Also with the cut set at 7500 rpm puts even further doubts on your map. Your map is basically russian roulette so id find another. Do a search for maps by bumpstart,aaron cake,rx72c id trust any of their info. I personally use 1 of bumpstart which is for standard primarys and 1000cc secondarys. If you cant find one better suited to your injectors use that map with mixtrim set to -15.That will start the car and have it running OK,put a smile on your face and be ready for the dyno.It will also save you a lot of dyno time and money. |
Your fuel system will also be close to maxed out.
IMO buy some 1000cc Marren injectors for the secondaries and use the bumpstart map to suit. I have similar setup to you and have done prob 10,000 kms incl track days with no problems. This map is 95% of the way there and safe.It could be perfected with a wideband which is the next step im taking. Personally i think a boosted rotor with an inexperienced microtech operator MAY not make it off the dyno alive. |
I'm running low boost and I'm not concerned with making big numbers. The car is a low budget project for racing in local autocross and hillclimb races. I just want to get some seat time and see how I like the car. When I want more power I'll definitely get some 1000-1200cc secondaries and switch the 720s to primaries.
I'm not the one who set the revcut to 7500. The ECU was used and came like that. I just didn't touch it; I haven't ever revved the car that high. I didn't change RPMwot or RPMcrs either. It says in the manual to set these points under load on a dyno... which is why I'm taking it to one:) I researched RPMlim vs. REVcut, as well as fuel vs. ignition limiting methods. I somewhat agree with your "fuel cut shouldnt be used" statements, but to say it should NEVER be used on a rotary is not true. I read of many instances of people who used the REVcut function regularly without any issues. Some even used it in place of a rev limiter. I agree with you that suddenly cutting fuel (and the lubricating, cooling premix in that fuel) at high RPMs is probably BAD for the motor and should be avoided at all costs. However, I think overboosting is far more detrimental. Overboosting creates a lean condition at the worst moment, when the engine is under extreme stress. The resulting knock can cause all sorts of destruction. The point of fuel cut in a factory ECU is to prevent this condition from ever happening, by taking the drastic step of shitting down the fuel system. Correct me if I'm wrong, but stock TIIs have a fuel cut, and for good reason. I'd like to add It says in the microtech manual that RPMlim should NEVER be used, because it does not cut fuel to the secondary injectors. The car keeps running, but on half the fuel, and the lean condition is quite dangerous. You will notice my RPMlim is off. What the microtech lacks is a true ignition cut. typically RPM limiters work by shutting off the ignition above a certain RPM, resulting in a rich condition and lots of backfiring, which I think is the least risky and damaging option. I'm going to set my REVcut to 9,500RMPS for now. I'm going to shift between 7-8k on the dyno and avoid the cut... But it is there in case I accidentally over-rev. I'd like to have a redline of around 8k, so I'm going to look into ways to cut the ignition. Supposedly you can send your microtech back to have an ignition control function added. There are also aftermarket products that work independently, like an MSD soft touch. http://www.summitracing.com/parts/ms...FYai4Aod2AIANQ Sorry, getting a bit off topic... I searched all the microtech posts by bumpstart and finally found his 550/1000cc map, as well as some good maps/info from rx72c. Thank you for that tip rx3sum. As soon as I have time I am going to try making changes to get somewhere closer to his map. I'll post back with results. Thank you for pointing out my low REVcut value. I would not have learned anything if you hadn't pointed it out. Any other tips will be appreciated... anyone? :) |
Im just starting out on the microtech journey like you and going through all the half and misinformations as you mentioned around the place. so after narrowing who definitely know what they are talking about a came up with the 3 authors mentioned.
I actually live in the same state as bumpstart and hes looked after my cars faultlessly so i follow exactly what he says.heres a quote of his been doing microtechs since before dot .. do not use the revlim ( soft cut 1/2 bank ) , revcut or boost cut ( full fuel cuts ) on rotors in a perfect world a full fuel cut would and should work ,, but in the microtech rotor world of leaking/ bigger injectors and flows and wet washed manifolds,. you are asking -nay- demanding -for shrapnel i have seen these repeatedly lean out rotors and kill them - in 15 years of using microtechs ,, you would think i would spot a pattern by now wouldnt you ?? some drag modified examples will have special flashed software and do an ignition cut but the vast majority will be fuel only ,, and you must use the screen 29 setup with timing retard as the two step if you wish to build in some safety for over rev and for over boost simply pull about 10 degrees out of the timing and add about 15% more fuel in the rev and boost map zones above your threshold this should safe the engine enough to cope with the spikes done right the engine will struggle to make more revs however the boost control is more fickle ,, done right boost will fall off,, but this will depend on the over fuel if not done right ( not enough over fuel ) you may get a little more overboost ( due to the retard ) ,, but the engine is ' soft tuned ' in this region for ig timing and should make flat power and not overload the engine ( but not load the engine and destroy it,, in effect a mild two step ) end bumpstart quote i always err on the side of caution as its way to easy to kill these engines with incorrect tuning. for what you are after put in the correct map from one of the big 3 lol and forget the dyno operator but obviously its your call. |
car made it off the dyno - and made 275.5whp at only 6000rpms. :P
It was boost creeping to 15psi above 6k, and the injector ms was nearing 14ms, so we backed off. Lots more work to come... |
Nice:nod: and thats some good power.Looks like more to come with a fuel system upgrade.
Time to go racing:icon_tup: Did you use your old map or bumps one?What areas did the tuner change? |
We started with bump's map. The car was pig rich when the secondary injectors staged, then became lean in the upper RPMs under boost. We lowered the injector staging to 2000rpms and 00" of vacuum, then set the load with all 4 injectors. It's running better now, but still needs lots of work and a retune. At least I can drive it now!
Might be able to make it to an autocross this year. |
You can bump up your dwell to 3.50 and will have no issues. I learned that from kilo racing! Anything above that will blow ignitors over time.
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