I got to thinking today when i was talking to one of my honda guru friends about my future ve setup. i explained to him that i was going to get the fac. ecu reprog. for the vvl setup through JWT, and use msd rpm act. switches for the cams. nothing special, right? he then asked me if the rpm activated switches alter the seperate fuel/ignition maps for the different cam profiles. I assume that the rpm activated switches somehow play into the ecu so the ecu knows when to switch to the more aggresive fuel/ignition maps, right?? HOW DOES IT DO THIS? he said that a lot of people he knew who put vtec motors in cars that didnt originally have vtec motors (no ecu vtec wires) and only used the apex v-afc had "half of vtec" he then stated that the vtec afc only activates the cams or something. this doesnt make sense to me. doesnt the air flow converter means that it alters something with air/fuel/ignition/timing??? i dont know.

someone please clear this up for me!

vafc, doesnt just activate vtec... it has programmable fuel maps corresponding to camshaft lobes... it will activate vtec, and change the fuel for the change of cam, whether it is going from big to small or small to big... you can set the changeover in acceleration as well as deceleration.

Now the Rpm pills do one thing: they activate the soleniod that in trubn operates the switching of camshaft lobes... if VVL is anything like vtec, it uses oil pressure to do the changing... (change oil every 2500 for better performance)


For both, correct me if I am wrong, the computer knows when its on the large cam, so it will adjust fuel mapping accordingly.

Originally posted by JDM_2ner
I he then asked me if the rpm activated switches alter the seperate fuel/ignition maps for the different cam profiles. I assume that the rpm activated switches somehow play into the ecu so the ecu knows when to switch to the more aggresive fuel/ignition maps, right??
I don't think JWT's ECU changes the fuel and timing maps when the cams switch to the more aggressive lobes. This is the reason I think it's so important to have the ECU tuned on a dyno and why I think there is plenty more HP to be had from these motors. I plan to give the Techtom program another try next spring in hopes of addressing this issue.

Remember Honda's do not have a Mass Airflow Meter. As a result they need to be tuned for each adittional mod to get the best effect. Nissan uses the MAF and in the case of a VE the MAF simple reconginizes that more air is going in a varies the the amount of fuel accordingly. As far as the ignition timing is concerned. If you get the JWT ECU he has already done the timing to correspond with the cams switching over at approximatly 5000rpm. He seems to like 5000rpm for some reason. So if you switch the intake at 4300 and the exhaust at 5000 then once you hit 5000 you are running the ecu and cams just as JWT intended. Anything other then that may not have the most optimized ignition mapping. It won't be a big deal. That is why you do dyno tuning to sort these things out. In the end the best switch point may be 5000rpm. It may not. That is why I chose the MSD.

Originally posted by Shoes59
I don't think JWT's ECU changes the fuel and timing maps when the cams switch to the more aggressive lobes.

Why would you say that? He tuned the car on the dyno and the road with the cams switch over and optimized both those parameters to HIS liking. I took my car to the dyno and just as Andreas thought JWT had run it a little rich. He says JWT likes to run things a little rich. Used the FPR to lean it out a little and I was right in the right spot around 13:1. I don't think that there is anything to be gained above 5000rpm with timing. I advanced mine and quickly lost power everywhere. A clear indication that timing is pretty good in all spots. I also thought I heard a ping down low. You have been driving around with the FPR set above factory specs. I don't understand how you can judge a ecu program when you purposely have been running it out of spec and on the rich side. It will prove nothing for you to go to this other tuner and show an increase in power if you never optimized the current setup.

the timing in the jwt program is set to the max i know that for sure. the fuel map is slightly conservative, but only slightly. and you should make sure whatever shop you go to actually has an accurate a/f reader. the ones you just stick in the tailpipe are not so good. if anything they are good as a relative reference. overall it is a decent drivably fun program.

it is true about the nissan having a maf so the computer doesnt chane maps but fuel is based on airflow measured no problem there.

[QUOTE]Originally posted by 98sr20ve
Why would you say that? I took my car to the dyno and just as Andreas thought JWT had run it a little rich. Used the FPR to lean it out a little and I was right in the right spot around 13:1.

I'm talking about remapping the ECU not just fiddling with fuel pressure and ignition timing. You seem to be forgetting the JWT ECU I have is not the same as yours. I was struggling with the surging condition and Clark made mapping changes he thought were necessary to make *my* car run right. Clark said there were subtle differences between the 94 ECU and other years. Kinda the bastard ECU if you will. My point is, there really isn't a plug and play ECU available for the VE or even a DE for that matter that will fully optomise the motors potential. JWT's is pretty good but I'm convinced there is more performance to be had through dyno tuning the ECU specific to the motor. That said, I'm not about to drive to California to have JWT tune my car. The only viable option for me is to give Yoshio another shot using the Techtom software.

OK so your ecu is different, I did not know that. You still haven't done the dyno tuning that would probably help the car. You are also running the FPR on the rich side. Unless you spend some time on the dyno tuning things a little it will never be a fair comparision between the Techtom and the JWT. I understand your reluctance to spend money on the JWT when your ultimate plan is to try the other. However, You also don't know how good your car might run by just putting it into the factory specifications. 15 degree's advance and 36 on the FPR would be a start. I would also clear the ecu and check your TPS at idle and WOT just to be sure.

Originally posted by bigtom
the timing in the jwt program is set to the max i know that for sure. the fuel map is slightly conservative, but only slightly. and you should make sure whatever shop you go to actually has an accurate a/f reader. the ones you just stick in the tailpipe are not so good. if anything they are good as a relative reference. overall it is a decent drivably fun program.


Funny story, Bigtom told me that 15 degree is the max with my car and the 93 octane I get here. He was 100% correct. Less then 93 I would back it down some form 15 degree's. I really didn't worry about the a/f reader as much as the power output. Leaned it out until the a/f was close. It also happened to make the most power that that point. We just set it back a little from that point. The shop I went to was very impressive. They had a KA24DE that made 280 hp NA on the engine dyno. They clearly knew what they were doing.

Originally posted by 98sr20ve
Unless you spend some time on the dyno tuning things a little it will never be a fair comparision between the Techtom and the JWT.
But I could care less about comparisons between the Wolf & Techtom units. All I know is the only way to fully optomise the engine is to dyno tune the ECU, not just the motor itself. The only feasible way for me to do that is to give Techtom another try. If it fails then I'll spend some time on the dyno with the Wolf unit to tune just the engine.