101 reasons you should dyno your stock car.

[hattech-v]

but make sure u buy 1 unit only... more than that i think is taxable..

 

[shiroitenshi]

Hmm.. an interesting note when I'm reading about required injector sizes..

according to the mat sallehs.. injector requirements are based on target horsepower at wheel.

So assuming my car makes 187hp on engine, I'd be needing 280cc injectors running at 80% duty cycle at 3 bar fuel press.

I'm sure if anyone of you who measured the injector duty cycle with a 'duty cycle' multimeter on the B-series (B16/B18) you noticed that it does indeed reach 100%. I didn't have one with those features, but hondata says it's 100%, so I guess that's open to debate.

Coincidentally, my car runs on 3.5bar at WOT, which means the 240cc injectors at 85% duty cycle puts out 272.45033896106645cc/m.. which puts the value at somewhere around 180hp flywheel power on this chart..

http://grabka.org/articles/injectorsize.php
(this I just randomly plucked off google, there are other that have very similar values)

Then again.. If hondata is right, then at peak, I'm running 100% duty cycle off the injectors, and I should get that number at flywheel, which I do, if that dastek dyno numbers means anything.. hahaha.

Hehehe.. interesting how the injector sizes and duty cycle corresponds to flywheel horsepower output.

Anyone care to test out this theory of mine on their ride? It's going to be an experience, I bet.. either my theory is gonna sink or swim depends on it as well.. :P

Chris, since you have logs of all your car tuning stuff.. mind pmming some? Let me pore over the data and see what's what..

Like your 205hp setup for example.. probably making something like 230-240 at the wheel, could be lower since your friction loss is probably lower due to the lightened cranks, no a/c and stuff.

so I need stuff like

a) injector size, which is probably 310cc (your RC eng injectors?)
b) fuel pressure, which is probably 3.5 bar at WOT, like mine.
c) max duty cycle, which is also likely 100%?

so, using those estimations...
at 85% duty cycle, your injectors put out
329.21082624462196cc/m, so if you extend that up too 100% duty cycle, it could possibly be near the 340cc/m mark, which coincidentally lines up with the 220flywheel horsepower mark.. I do note that although you're probably using the stock regulator, you're probably running an upgraded fuel pump (I think) which bumps up the pressure a little, so the actual fuel flow could 'theoretically be higher'.

Another sample is the 200whp (228 on engine) that is running 4.5bar fuel pres at WOT, then also has the injectors past the 100% duty cycle, running on the pitiful 240cc injectors, which should be delivering fuel around 308.9296463598144cc/m at 85% duty cycle at that pressure, and at 100% duration, probably a bit higher due to the fact that the car is also using an uprated fuel pump.. (too lazy to calculate further)
and guess what? it falls into the near hp target range as well. (see chart in the link above)
Which is one of the reasons why I think that most people overestimate how much fuel the stock injector puts out or how much hp correlates with injector sizing, duty cycle, fuel pressures, etc.

Interesting how all this data correlates with horsepower numbers..
Should have more sample to accurately prove how all these maths prove in terms of peak hp output.

hehehe.. more maths anyone?

Then again.. this stuff I made up could be total bullocks, so let's see if these stuff holds true.. more data, people! :P

I'm hoping to come close to at least guessing engine hp number (with an error margin of 10hp or less) by looking at injector size, duty cycle, and fuel pressure.

Amazing how my curiosity of why americans plonk in big cc injectors in an NA setup takes me.. :P

 

[J101]

- im not sure if hondata s300 has the setup for injector lagtime, with this you can alter the volts for your aftermarket injectors appropriately so it doesnt show 100%all the time.

- yes indeed they said 100% duty cycle for 240cc, but that is for the b16a and b18c basemaps. stock basemaps and not rojaks with 2L blocks and other aftermarket combination. they assume you can pull new settings from the basemaps.

- if you have notice emanage has a percentage difference(compensation) if you put a bigger size injectors.

the americans has been using hondata and power-fc on their hondas. its not taboo for them to use 440cc on a b16a since they can control the injectors and its a 1 time purchase. then again, more fuel is always better than less fuel, if you can control it.

commonly the 240cc also can be use on a mildy(basic) 2L setup and commonly phrase "sureeeeeeee cannnnnnnn oneeeeeeee"...yeah if the a/f ratio is nice on the dyno.

the bang for the buck malaysia-boleh will always be pushing the FPR(4-5 bar), running on some supra/rx7 fuel pump and maxing the stock injectors. its all matter of time when the injector starts to jam and mrs detonation is knocking on your door...ha ha ha

 

[chris2000]

Then again.. If hondata is right, then at peak, I'm running 100% duty cycle off the injectors, and I should get that number at flywheel, which I do, if that dastek dyno numbers means anything.. hahaha.

Hehehe.. interesting how the injector sizes and duty cycle corresponds to flywheel horsepower output.

Anyone care to test out this theory of mine on their ride? It's going to be an experience, I bet.. either my theory is gonna sink or swim depends on it as well.. :P

The mat selleh standards are normally, " car can only run safe with 80-85% injector duty cycle". If it reaches or exceeds, they will always change injectors. There is another 15-20% injector duty, but they stay:mouth_closed: away from them as an insurance when they need it.

In my older days with Putra Turbo, i used to use stock injectors with stock fuel pumps and with FSE regulator. Old style, just bump up pressure to get require fuelling. Then i noticed though FSE is reputable brand, the fuel pressure does fluactuates a bit from tuning and after a couple of weeks, the pressure is not the same as what is set and need re-setting. How i found out? Coz my exhaust Temp was a little higher and i check fuel pressure to see it lowered. Used this setup for a few months till my injector/regulator jammed!! :confused_smile:

From then on, i swapped back for OEM regulators, chaged to RX-7 fuel pump and bigger injectors from VR4 RS (450cc) and was boosting 1.2bar through a TD05 to get over 230whp. The car is still running strong since 2000 mods and only did require a maintainenace overhaul in Feb 2007.

Since then my lesson learn if power go up I will need to the following:-
1. change fuel pump
2. the injectors if max out

All the above with STOCK regulators.

 

[chris2000]

Chris, since you have logs of all your car tuning stuff.. mind pmming some? Let me pore over the data and see what's what..

Like your 205hp setup for example.. probably making something like 230-240 at the wheel, could be lower since your friction loss is probably lower due to the lightened cranks, no a/c and stuff.

so I need stuff like

a) injector size, which is probably 310cc (your RC eng injectors?)
b) fuel pressure, which is probably 3.5 bar at WOT, like mine.
c) max duty cycle, which is also likely 100%?

I'm hoping to come close to at least guessing engine hp number (with an error margin of 10hp or less) by looking at injector size, duty cycle, and fuel pressure.

Amazing how my curiosity of why americans plonk in big cc injectors in an NA setup takes me.. :P

My 205whp B18C setup on fuelling:-
Stock ITR Fuel regulator
Sard 280L Fuel Pump
RC 270cc injectors
all run on a very rich endurance tuned J's Racing N1 ECU

A 200whp B16A setup i seen:-
Stock ITR fuel Regulator
Walboro 255L fuel pump
ITR 240cc injectors
all run on Hondata S300. Remember seeing at very high revs was injector 100% but can't remember at what point. The file is on another computer at my mech place.

A very old and lousy tune i did in 2006, the car made 186whp on B18c and we try running the RC310cc, the Hondata only showed about 72% duty at WOT at 8400rpm. Where else before injector change, we were 100% duty at WOT 7800rpm. :shocked:

 

[chris2000]

- im not sure if hondata s300 has the setup for injector lagtime, with this you can alter the volts for your aftermarket injectors appropriately so it doesnt show 100%all the time.

- yes indeed they said 100% duty cycle for 240cc, but that is for the b16a and b18c basemaps. stock basemaps and not rojaks with 2L blocks and other aftermarket combination. they assume you can pull new settings from the basemaps.

- if you have notice emanage has a percentage difference(compensation) if you put a bigger size injectors.

the americans has been using hondata and power-fc on their hondas. its not taboo for them to use 440cc on a b16a since they can control the injectors and its a 1 time purchase. then again, more fuel is always better than less fuel, if you can control it.

commonly the 240cc also can be use on a mildy(basic) 2L setup and commonly phrase "sureeeeeeee cannnnnnnn oneeeeeeee"...yeah if the a/f ratio is nice on the dyno.

the bang for the buck malaysia-boleh will always be pushing the FPR(4-5 bar), running on some supra/rx7 fuel pump and maxing the stock injectors. its all matter of time when the injector starts to jam and mrs detonation is knocking on your door...ha ha ha

S300 can set for injector size. You will have to key in 240cc for stock injectors and current injectors if stock then type 240cc if 440cc then key 440cc.

From here Hondata will take over and allow your car idle almost like stock 240cc. :shades_smile:

 

[shiroitenshi]

S300 can set for injector size. You will have to key in 240cc for stock injectors and current injectors if stock then type 240cc if 440cc then key 440cc.

From here Hondata will take over and allow your car idle almost like stock 240cc. :shades_smile:

Yeah.. actually they can compensate the injector duration when you enter the values.. played with the app for a while already. It's a no brainer to plug in the bigger injectors (with the resistor box if required) and then change the injector size, and you notice the fuel map is adjusted accordingly.. neat stuff.. :P

but Chris, your BFSC is sure very low if you can hit 200+ whp (220-230 on engine?) with 310 injectors at only 7x+% duty cycle.

 

[shiroitenshi]

- im not sure if hondata s300 has the setup for injector lagtime, with this you can alter the volts for your aftermarket injectors appropriately so it doesnt show 100%all the time.

- yes indeed they said 100% duty cycle for 240cc, but that is for the b16a and b18c basemaps. stock basemaps and not rojaks with 2L blocks and other aftermarket combination. they assume you can pull new settings from the basemaps.

- if you have notice emanage has a percentage difference(compensation) if you put a bigger size injectors.

the americans has been using hondata and power-fc on their hondas. its not taboo for them to use 440cc on a b16a since they can control the injectors and its a 1 time purchase. then again, more fuel is always better than less fuel, if you can control it.

commonly the 240cc also can be use on a mildy(basic) 2L setup and commonly phrase "sureeeeeeee cannnnnnnn oneeeeeeee"...yeah if the a/f ratio is nice on the dyno.

the bang for the buck malaysia-boleh will always be pushing the FPR(4-5 bar), running on some supra/rx7 fuel pump and maxing the stock injectors. its all matter of time when the injector starts to jam and mrs detonation is knocking on your door...ha ha ha

True, but one thing I noticed is that the injectors start to sputter if it's pushed beyond it's limit.. during a tune, observed that with too long an injector duration, the a/f ratio bounces all over the place.. it drop to lean at around 15-16+, then suddenly very rich at 10+ AFR.

During this time, the car jerks like mad.

Curiously enough this happens only during the vtec point.. I think it's something to do with the pre-vtec fuel enrichment on the ECU just before the vtec engages, which is just enough to send the injectors to the edge.

Hopefully with an injector change and a retune, can get that elusive 200whp at 8K on a 1.8+L engine, and 215whp.. (hopefully). It should be soon, although the date is still tentative.

Cross fingers and hope for the best.. :P

 

[shiroitenshi]

My 205whp B18C setup on fuelling:-
Stock ITR Fuel regulator
Sard 280L Fuel Pump
RC 270cc injectors
all run on a very rich endurance tuned J's Racing N1 ECU

Hmm.. how much does the higher rated fuel pump bump up fuel pressure...? Did you plug in a fuel pres. to find out?

With the stock honda fuel pump, the ITR regulator puts out 3.5bar (tested), with the higher flow rate of the fuel pump, I wonder how much fuel pressure at the fuel rail?

Actually I'm also curious about the stock capacities of the stock fuel pump.. I should try and test it during one of these holidays.

 

[J101]

instead of squeezing the injectors or increasing fuel pump size, squeeze the voltage on the current fuel pump and maintain fuel pressure. msd made a voltage regulator for this. do check it out.

True, but one thing I noticed is that the injectors start to sputter if it's pushed beyond it's limit.. during a tune, observed that with too long an injector duration, the a/f ratio bounces all over the place.. it drop to lean at around 15-16+, then suddenly very rich at 10+ AFR.

During this time, the car jerks like mad.

 

[chris2000]

Yeah.. actually can they compensate the injector duration when you enter the values.. played with the app for a while already. It's a no brainer to plug in the bigger injectors (with the resistor box if required) and then change the injector size, and you notice the fuel map is adjusted accordingly.. neat stuff.. :P

but Chris, your BFSC is sure very low if you can hit 200+ whp (220-230 on engine?) with 310 injectors at only 7x+% duty cycle.

My 70+% duty with 310cc is in B18C making only 186whp and not 200+whp. :regular_smile:

 

[chris2000]

True, but one thing I noticed is that the injectors start to sputter if it's pushed beyond it's limit.. during a tune, observed that with too long an injector duration, the a/f ratio bounces all over the place.. it drop to lean at around 15-16+, then suddenly very rich at 10+ AFR.

During this time, the car jerks like mad.

Curiously enough this happens only during the vtec point.. I think it's something to do with the pre-vtec fuel enrichment on the ECU just before the vtec engages, which is just enough to send the injectors to the edge.

Hopefully with an injector change and a retune, can get that elusive 200whp at 8K on a 1.8+L engine, and 215whp.. (hopefully). It should be soon, although the date is still tentative.

Cross fingers and hope for the best.. :P

From my experience, the A/F jumps around because the car is jerking and not because a/f is jumping causing car to jerk.

And this jerk if it happens will always happen only in vtec transition point or part throttle in higher rev like 7k, 8k rpm etc.

I don't exactly know why it happens but i know for sure if cam gear settings are not optimal setting for your specific engine build, compression etc, this will always happen and also if the vtec point and iginition + fuel map is not ideal it will happen.

My 1st cam i used was Jun2 and Jun3. Both this cam had crazy mis-fire or jerk during vtec transition and part throttle. No matter how we set the cam gear, it could not be eliminated with retaining good power. all this was done in old skool style with a re-chip ecu.

The EK i know for sure, after install S300 and did a good tune and setting vtec point high the vtec transition was smooth and alot less jerk at part throttle.

My recent cam installation on the Buddy clubs, when the camgear setting not ideal, it was jerking like help in vtec transition. Now solved with only camgear setting.

 

[V8_nutter]

From my experience, the A/F jumps around because the car is jerking and not because a/f is jumping causing car to jerk.

And this jerk if it happens will always happen only in vtec transition point or part throttle in higher rev like 7k, 8k rpm etc.

I don't exactly know why it happens but i know for sure if cam gear settings are not optimal setting for your specific engine build, compression etc, this will always happen and also if the vtec point and iginition + fuel map is not ideal it will happen.

My 1st cam i used was Jun2 and Jun3. Both this cam had crazy mis-fire or jerk during vtec transition and part throttle. No matter how we set the cam gear, it could not be eliminated with retaining good power. all this was done in old skool style with a re-chip ecu.

The EK i know for sure, after install S300 and did a good tune and setting vtec point high the vtec transition was smooth and alot less jerk at part throttle.

My recent cam installation on the Buddy clubs, when the camgear setting not ideal, it was jerking like help in vtec transition. Now solved with only camgear setting.

yup,,mostly like cam gear "lari 1 gigi".

 

[zaki]

From my experience, the A/F jumps around because the car is jerking and not because a/f is jumping causing car to jerk.

And this jerk if it happens will always happen only in vtec transition point or part throttle in higher rev like 7k, 8k rpm etc.

I don't exactly know why it happens but i know for sure if cam gear settings are not optimal setting for your specific engine build, compression etc, this will always happen and also if the vtec point and iginition + fuel map is not ideal it will happen.

My 1st cam i used was Jun2 and Jun3. Both this cam had crazy mis-fire or jerk during vtec transition and part throttle. No matter how we set the cam gear, it could not be eliminated with retaining good power. all this was done in old skool style with a re-chip ecu.

The EK i know for sure, after install S300 and did a good tune and setting vtec point high the vtec transition was smooth and alot less jerk at part throttle.

My recent cam installation on the Buddy clubs, when the camgear setting not ideal, it was jerking like help in vtec transition. Now solved with only camgear setting.

I experienced the opposite. The car was jerking while cruising at high RPM because the A/F was jumping around. the reading was fluctuating like hell. when the ecu reads high vacuum column, it gave too lean something like 17-18. when the ecu reads low vacuum (just below the high vacuum column), the reading was too rich 10 - 11. and that was on the cruising part (part throttle) after VTEC is engaged somewhere between 6000 - 8000RPM.

cruising b4 VTEC and WOT were perfect.
The car was on jun 3 setup and was degreed according to the cam card. after sometime, the a/f got stable. it was like PITA!! i can see that rechipped ECUs have this problem with aftermarket cams but not all.

 

[J101]

chris,
u actually said the solution, prolly u didnt realise this chris. its the vtec transition point that makes the jerk. the primary cam profile on the cams especially JUN are meant to be pushed betwen 5800 to 6800. this may sound absurb for newbies but the power hasnt died yet at the mid range. the rest of the rpm are pulled untill 9200rpm. but for street setup (mild modded) no doubt between 7800-9200 the engine is dying to be pushed which wasnt meant to rev that high either. cam gears do help with the power band but not make more power as ppl believe.

i think the toda c2 should be good in all ranges, aint that right chris? hee hee hee

 

[hattech-v]

why today c2 is good?

 

[J101]

from your question, did u buy toda c yesterday? ha ha ha

why today c2 is good?

 

[hattech-v]

just now la...

 

[chris2000]

chris,
u actually said the solution, prolly u didnt realise this chris. its the vtec transition point that makes the jerk. the primary cam profile on the cams especially JUN are meant to be pushed betwen 5800 to 6800. this may sound absurb for newbies but the power hasnt died yet at the mid range. the rest of the rpm are pulled untill 9200rpm. but for street setup (mild modded) no doubt between 7800-9200 the engine is dying to be pushed which wasnt meant to rev that high either. cam gears do help with the power band but not make more power as ppl believe.

i think the toda c2 should be good in all ranges, aint that right chris? hee hee hee

I know because when i 1st used jun3 with re-chipped "ATCC" spec for Type R cams, the Vtec point was 4800rpm, hence the crazy jerk. When we use the Jun3 with Hondata it was raise to 6000rpm, and jerk was alot less man.

C2?? apa ar?? hehe.. High high primaries.... Wait till the Skunk2 Pro comes, i'll call you over to see them :regular_smile:


Your white EK friend was here just now. We played around with Omni Springs, Omni retainers, Skunk2 Pro Retainers and Toda valve springs.

1st time i actually played around with it. The Omni retainers was really a snap fit like they advertised. Pretty suprise too me. Ask your friend who witness it. :shocked:

The Skunk2 Pro retainers had a 0.3mm bigger base than Omni and fitted Toda Springs very well with minimal free play. It fitted bettter on the toda valve springs then Omni, Crower and Brian Crower.

We will see how it goes on his car.

 

[shiroitenshi]

I experienced the opposite. The car was jerking while cruising at high RPM because the A/F was jumping around. the reading was fluctuating like hell. when the ecu reads high vacuum column, it gave too lean something like 17-18. when the ecu reads low vacuum (just below the high vacuum column), the reading was too rich 10 - 11. and that was on the cruising part (part throttle) after VTEC is engaged somewhere between 6000 - 8000RPM.

cruising b4 VTEC and WOT were perfect.
The car was on jun 3 setup and was degreed according to the cam card. after sometime, the a/f got stable. it was like PITA!! i can see that rechipped ECUs have this problem with aftermarket cams but not all.

Yup.. exactly.. cruising b4 vtec and wot is perfect.. same story with yours zaki.

And I suspect the A/F jumped around due to the sputtering of the injectors.. looking at the AF reading, the a/f started reading lean gradually (in the span of 1-2 secs (mind you, this is at part throttle, not WOT run) before the a/f became something like 10.5 then the jerks started, and then only did the a/f ratio jumped around.

It actually felt like a rev cut.. except more severe in the sense that it actually 'slows' down the car. (of course, that could be attributed to having a car that runs on 205/50/15 tires. :P)

Same problem lah zaki.. the way you decribed it similar. I suspect it's some problem with the rechipped ecu putting too much enrichment during the vtec crossover point.

Same also with the a/f becoming stable after a while.. but only when it's cold (relatively speaking in engine temps).. when it's hot.. it starts all over again.

but looking at the torque output.. it seems due to the compression, the cams want to be open early, but the jerking problem rears its ugly head.

So finally chose a higher point and the jerking disappears, (although curiously, I noticed that vtec engagement enrichment is still there (though tuned out moderately) and also some measure of power output.

Well, the specs of the cam are also degreed in properly, so shouldn't be a problem.. but playing with the overlap is also not an option, due to the fact that the clearance is rather very minimal..(based on the piston compression height and gasket thickness (god knows the valve relief clearance.) So I do not think it's wise to hold this engine at 9K for long.

It's just one of the problems of not having the engine built yourself, I guess.