20B NA update - dyno results (LONG)
05-09-04, 01:10 AM
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20B NA update - dyno results (LONG)
Welp, we finally got everything sorta, kinda (see below) working enough to hit the dyno.
It was a DynoJet model 224 that was in-the-ground.
Recap of the set-up...
Bone stock 20B, no turbos, custom unequal length header (2" primaries), 3" exhaust, Walker Dynomax UltraFLO Race Magnun pre-silencer 3" center / center, Borla "ProXS" 3" center / offset rear muffler
Haltech E6K controlled
MSD DIS-4 "ignitor"
trio of stock FC3S leading coils, one coil per rotor firing both leading and trailing at the same time, i.e. no spark split
stock fuel injectors (6 x 550)
stock FC3S turbo fuel pump
We were fighting high RPM misfires, so getting a clean run wasn't very easy.
The very first run was 210+hp, so the monkey was off out backs. If it was under 200hp, it would've been a major disappointment. I was estimating 230 to 250 to the wheels prior to hitting the dyno. Mind you, it hit 210hp way under the normal 7kRPM redline - I think it hit that number at around 6kRPM at the most - I think it was lower at 5.5k or even down to 5kRPM.
Torque was almost ruler flat from 3k on up.
When we got the engine to rev up past 7kRPM, it hit a max of 232hp (to the rear wheels). It nails my estimate on the head, but we weren't able to get any significant gains above that. I *think* the torque number was above 200lb-ft. Sorry I got no pics or graphs, as the DynoJet was running off a frag box with no floppy or printer connected - all it had was a CD drive, which I don't think was a burner. I'll try and grab the graphs off the frag box sometime soon. Right after the last run, the frag box froze, and we didn't bother to reboot it to look at the graphs again.
We found out by accident that the air filter was choking the engine down. It was a cheapie K&N rip-off that was 3" inlet, 7" base, 5" top, 6" tall, with the inverted done center top (ala R.S. Akimotor Funnel Ram style). The cone filter broke it's clamp, and we did one run without it. The run without the air filter dropped power - doh. Looking at the AFR's, it dropped at least half an AFR point so the power drop was due to it running lean - restrictive filter, DOH.
We were already running about 25-degrees if total advance, and I started to mess with the ignition timing map. Dropping it 5-degrees did not adversely affect power output; in fact it gained a little at the very high end, over 6kRPM. I dropped the timing down to 15-degrees total advance, and power started to drop drastically. We left the timing at 20-degree total advance for safety.
The biggest gains were oddly made by changing the Haltech timing output type. Those who are familiar with the Haltech controls will understand "constant charge" versus "constant duty". We initially had it set to constant duty 50%, but there was conflicting recommendation on what we should set it at - I've also heard constant charge 3.5ms to constant charge 0.8ms. From CC 50%, we dropped it down to CC 30%, and we got almost a 5hp jump across the board! Dropping it down to CC 20% dropped the power across the board. Changing to CD 3.5ms matched initial power runs (not the high CC 30% one). Dropping the CD charge time to 2.0 introduced high RPM misfire over 6kRPM. Dropping the CD charge time to 1.0ms, and the high RPM misfire was very apparant. Changing the setting back to CC 30%, and we got all the power back.
Peak torque was about 5.5kRPM - it was kinda high and surprised me. Peak power was up at 7kRPM. Remember, this is a stock STOCK motor.
We had the car on the dyno for about an hour and a half to get all of this taken care of. Except for the high RPM misfire, things went very smoothly. The torque band is amazing broad. The power output was low, but after we found out the filter was choking the engine, I would be confident we could break the 250hp mark with a larger air filter. The Haltech showed 73% - 74% max duty cycle, so were getting really close to the max safe capacity of the stock fuel injectors - yikes! I think the stock FC turbo fuel pump is also close to capacity, as AFR's was getting all weird during all the runs. Backing out 232hp with a standard 15% drivetrain friction loss, I calculate 270hp to 280hp at the flywheel; that is very close to the stock power output, but we used no turbos!
We would've been a lot happier with some higher numbers, but the owner is happy...I think the word here is "relieved"...on what the car did on the DynoJet. I think things went relatively well. The car did not very much more power than our initial tuning - no wide-band, street tuning, and only an EGT gauge and a narrow-band AFR gauge (20-segement Autometer) to help us. I was glad we got the ignition timing total advance down, as I was worried with the 25-degree total advance we were running. The ignition output setting was an eye-opener on the MSD DIS-4, as were didn't think we would get any significant gains from messing with it! On top of all of this, initial half tank estimates on mileage come out to around 14mpg - WOW. This includes all out WOT tuning trying to get everything tuned - WOW.
Sorry for not getting any sound clips! We blew the exhaust gasket initially, and it took a while to get a couple of flanges installed - we only got the exhaust fixed a couple days prior to the dyno day. We blew the gasket at the newly welded in flanges at the end of the dyno run, so we need to fix it again.
Sorry for the length!
-Ted
It was a DynoJet model 224 that was in-the-ground.
Recap of the set-up...
Bone stock 20B, no turbos, custom unequal length header (2" primaries), 3" exhaust, Walker Dynomax UltraFLO Race Magnun pre-silencer 3" center / center, Borla "ProXS" 3" center / offset rear muffler
Haltech E6K controlled
MSD DIS-4 "ignitor"
trio of stock FC3S leading coils, one coil per rotor firing both leading and trailing at the same time, i.e. no spark split
stock fuel injectors (6 x 550)
stock FC3S turbo fuel pump
We were fighting high RPM misfires, so getting a clean run wasn't very easy.
The very first run was 210+hp, so the monkey was off out backs. If it was under 200hp, it would've been a major disappointment. I was estimating 230 to 250 to the wheels prior to hitting the dyno. Mind you, it hit 210hp way under the normal 7kRPM redline - I think it hit that number at around 6kRPM at the most - I think it was lower at 5.5k or even down to 5kRPM.
Torque was almost ruler flat from 3k on up.
When we got the engine to rev up past 7kRPM, it hit a max of 232hp (to the rear wheels). It nails my estimate on the head, but we weren't able to get any significant gains above that. I *think* the torque number was above 200lb-ft. Sorry I got no pics or graphs, as the DynoJet was running off a frag box with no floppy or printer connected - all it had was a CD drive, which I don't think was a burner. I'll try and grab the graphs off the frag box sometime soon. Right after the last run, the frag box froze, and we didn't bother to reboot it to look at the graphs again.
We found out by accident that the air filter was choking the engine down. It was a cheapie K&N rip-off that was 3" inlet, 7" base, 5" top, 6" tall, with the inverted done center top (ala R.S. Akimotor Funnel Ram style). The cone filter broke it's clamp, and we did one run without it. The run without the air filter dropped power - doh. Looking at the AFR's, it dropped at least half an AFR point so the power drop was due to it running lean - restrictive filter, DOH.
We were already running about 25-degrees if total advance, and I started to mess with the ignition timing map. Dropping it 5-degrees did not adversely affect power output; in fact it gained a little at the very high end, over 6kRPM. I dropped the timing down to 15-degrees total advance, and power started to drop drastically. We left the timing at 20-degree total advance for safety.
The biggest gains were oddly made by changing the Haltech timing output type. Those who are familiar with the Haltech controls will understand "constant charge" versus "constant duty". We initially had it set to constant duty 50%, but there was conflicting recommendation on what we should set it at - I've also heard constant charge 3.5ms to constant charge 0.8ms. From CC 50%, we dropped it down to CC 30%, and we got almost a 5hp jump across the board! Dropping it down to CC 20% dropped the power across the board. Changing to CD 3.5ms matched initial power runs (not the high CC 30% one). Dropping the CD charge time to 2.0 introduced high RPM misfire over 6kRPM. Dropping the CD charge time to 1.0ms, and the high RPM misfire was very apparant. Changing the setting back to CC 30%, and we got all the power back.
Peak torque was about 5.5kRPM - it was kinda high and surprised me. Peak power was up at 7kRPM. Remember, this is a stock STOCK motor.
We had the car on the dyno for about an hour and a half to get all of this taken care of. Except for the high RPM misfire, things went very smoothly. The torque band is amazing broad. The power output was low, but after we found out the filter was choking the engine, I would be confident we could break the 250hp mark with a larger air filter. The Haltech showed 73% - 74% max duty cycle, so were getting really close to the max safe capacity of the stock fuel injectors - yikes! I think the stock FC turbo fuel pump is also close to capacity, as AFR's was getting all weird during all the runs. Backing out 232hp with a standard 15% drivetrain friction loss, I calculate 270hp to 280hp at the flywheel; that is very close to the stock power output, but we used no turbos!
We would've been a lot happier with some higher numbers, but the owner is happy...I think the word here is "relieved"...on what the car did on the DynoJet. I think things went relatively well. The car did not very much more power than our initial tuning - no wide-band, street tuning, and only an EGT gauge and a narrow-band AFR gauge (20-segement Autometer) to help us. I was glad we got the ignition timing total advance down, as I was worried with the 25-degree total advance we were running. The ignition output setting was an eye-opener on the MSD DIS-4, as were didn't think we would get any significant gains from messing with it! On top of all of this, initial half tank estimates on mileage come out to around 14mpg - WOW. This includes all out WOT tuning trying to get everything tuned - WOW.
Sorry for not getting any sound clips! We blew the exhaust gasket initially, and it took a while to get a couple of flanges installed - we only got the exhaust fixed a couple days prior to the dyno day. We blew the gasket at the newly welded in flanges at the end of the dyno run, so we need to fix it again.
Sorry for the length!
-Ted
Last edited by RETed; 05-09-04 at 01:25 AM.
05-09-04, 10:14 AM
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thats pretty cool! i'm ready to pull my turbos off i think.
ivans truck (stock stock, sequential) only put down 230 or so hp.....
um make that header longer! racing beat has 2 exhausts for the 1st gen, a short header and a long header. they are very close in peak power, but the long headers have much better low and midrange.
ivans truck (stock stock, sequential) only put down 230 or so hp.....
um make that header longer! racing beat has 2 exhausts for the 1st gen, a short header and a long header. they are very close in peak power, but the long headers have much better low and midrange.
05-09-04, 12:52 PM
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heres the link to the stock stock stock dyno #'s
https://www.rx7club.com/showthread.p...hreadid=266787
looks like the turbos are worth 5hp....
https://www.rx7club.com/showthread.p...hreadid=266787
looks like the turbos are worth 5hp....
05-09-04, 03:16 PM
#6
Originally posted by j9fd3s looks like the turbos are worth 5hp....
You get to remove 62+ pounds from the side of the engine (manifold, twins and down pipe) and replace it with 1/3 the weight. My short header is only 21.5 pounds.
05-09-04, 06:15 PM
#7
Old [Sch|F]ool
Hey RETed, I have "heard" from a racer-type that you do not want to run a dual-post coil on both leading and trailing of the same rotor. Problem being that in their natural state, one cylinder/rotor is under very little pressure, at the top of the exhaust stroke (so it's pretty much a dead short) while the other one is under high pressure (needs lots of juice to fire). If you run both ends of the coil to the same rotor, both ends require a lot of power, and the coil simply cannot provide that much. Maybe the MSD can help compensate but I doubt it, there's only so much energy a coil can store.
Further evidence supporting my theory (that this is why you were having ignition issues): For quite a few years, Ford sold a DIS version of their twin plug 2.3/2.5 OHC engine. In this case, even though it has four double-ended coils and four two-plug cylinders, the coils are routed such that each end of each coil pack goes to different cylinders, just like a regular single-plug engine. Reroute the plug wires so each cylinder has its own coil and it doesn't run so good.
Further evidence supporting my theory (that this is why you were having ignition issues): For quite a few years, Ford sold a DIS version of their twin plug 2.3/2.5 OHC engine. In this case, even though it has four double-ended coils and four two-plug cylinders, the coils are routed such that each end of each coil pack goes to different cylinders, just like a regular single-plug engine. Reroute the plug wires so each cylinder has its own coil and it doesn't run so good.
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05-09-04, 09:28 PM
#8
That's some great info.
Hey peejay, have you ever heard of anyone running 0 and 180 degree leading sparks on a 20B? I'll find out probably this week whether it works or not. The induction is also experimental; I've decided to try a dellorto 48DHLA for now before going FI. Sorry to jack the thread.
Hey peejay, have you ever heard of anyone running 0 and 180 degree leading sparks on a 20B? I'll find out probably this week whether it works or not. The induction is also experimental; I've decided to try a dellorto 48DHLA for now before going FI. Sorry to jack the thread.
05-09-04, 11:26 PM
#10
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Re: 20B NA update - dyno results (LONG)
Originally posted by RETed
We were fighting high RPM misfires, so getting a clean run wasn't very easy.
We were fighting high RPM misfires, so getting a clean run wasn't very easy.
05-09-04, 11:33 PM
#11
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Evil, that was what I was suggesting. 
It's so easy to spend other people's money isn't it?
The way I see it, either one can spend $240 on six MSD Blaster coils, or one could go to the three dead FCs that the leading coils came from, and grab the trailing coil packs. (the trailing pack is two separate coils, not a double ended one) Either way the coils would be driven in parallel.
john: You certainly can do 180 dergee leading sparks... just not at the same time as the other leading plugs.
It's so easy to spend other people's money isn't it?The way I see it, either one can spend $240 on six MSD Blaster coils, or one could go to the three dead FCs that the leading coils came from, and grab the trailing coil packs. (the trailing pack is two separate coils, not a double ended one) Either way the coils would be driven in parallel.
john: You certainly can do 180 dergee leading sparks... just not at the same time as the other leading plugs.
05-10-04, 06:46 AM
#14
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Finally!
A little over 550K...
http://fc3spro.com/PICS/SKY20B/20b01.mpg
Dunno why it was acting funny...
Car sat overnight, and started once to get it warmed up.
We did the video when Autometer water temp guage indicated 160F.
I think the coolant temps need a little tweaking; there are no hesitations at normal temps 180F to 190F.
Crank, start...
Several revs to 7kRPM (sounds much lower than 7kRPM???)
Rev down to 3k, several throttle stabs - ah OS Giken triple with ulta-light flywheel
Enjoy!
-Ted
A little over 550K...
http://fc3spro.com/PICS/SKY20B/20b01.mpg
Dunno why it was acting funny...
Car sat overnight, and started once to get it warmed up.
We did the video when Autometer water temp guage indicated 160F.
I think the coolant temps need a little tweaking; there are no hesitations at normal temps 180F to 190F.
Crank, start...
Several revs to 7kRPM (sounds much lower than 7kRPM???)
Rev down to 3k, several throttle stabs - ah OS Giken triple with ulta-light flywheel
Enjoy!
-Ted
05-10-04, 01:47 PM
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Yeah, exact same motor in the green/blue FC.
I'm pretty sure the coolant temp correction maps need a little adjusting.
When fully warmed up, it would pop flames out the exhaust all the time - it didn't do that ONCE during the filming.
Odd.
-Ted
I'm pretty sure the coolant temp correction maps need a little adjusting.
When fully warmed up, it would pop flames out the exhaust all the time - it didn't do that ONCE during the filming.
Odd.
-Ted
05-10-04, 08:42 PM
#18
Old [Sch|F]ool
Originally posted by Jeff20B
That does sound a bit different. That's not the same engine that was in the green car, is it?
Now I'm really curious to know how mine will sound. I'm going to start fabbing the carb adaptor today.
That does sound a bit different. That's not the same engine that was in the green car, is it?
Now I'm really curious to know how mine will sound. I'm going to start fabbing the carb adaptor today.
05-10-04, 09:42 PM
#19
The V8 valve cover is way too long to fit in the engine bay next to the engine. A V6 valve cover might work, but I don't have any handy to measure.
Instead, what I'm going to try is to keep the stock LIM and UIM and adapt a dellorto 48DHLA to where the TB used to be. The carb's 48mm barels are similar in diameter to the 20B's secondary figure 8 opening. The UIM ports are siamesed while the dellorto's are seperated by a little.
The stock UIM is a plenum/dynamic chamber where it says 3ROTOR, so it won't suck on the dellorto the same way a standard two rotor RB manifold would. I don't know if the carb will like a smoother flow than what RB tuned it for. Or maybe it doesn't matter to a dellorto?
The only thing I'm going to be making from scratch is the adaptor. I'd like to make it flow into the primary port as well, but there may not be enough room due to the brake master cylinder. Think RX-3 engine bay.
These are right hand drive, but they're similar to what mine looks like.
http://au.f2.pg.photos.yahoo.com/ph/...bum?.dir=/d184
http://www.hitman.hm/toy12a.htm
If the carb won't work, I'll have to go with a megasquirt I suppose. Someone will probably need to fab me up a secondary fuel rail because the stocker is way too long. Or I could try an Atkins 20B 9" SC manifold (no SC) and my Edlebrock. I was affraid the front rotor would go lean under acceleration, so that's why I'm going to try the stock upper and lower manifolds first. An SC would be nice, but it's like $3000. Heh, I can't even afford a megasquirt right now.
Instead, what I'm going to try is to keep the stock LIM and UIM and adapt a dellorto 48DHLA to where the TB used to be. The carb's 48mm barels are similar in diameter to the 20B's secondary figure 8 opening. The UIM ports are siamesed while the dellorto's are seperated by a little.
The stock UIM is a plenum/dynamic chamber where it says 3ROTOR, so it won't suck on the dellorto the same way a standard two rotor RB manifold would. I don't know if the carb will like a smoother flow than what RB tuned it for. Or maybe it doesn't matter to a dellorto?
The only thing I'm going to be making from scratch is the adaptor. I'd like to make it flow into the primary port as well, but there may not be enough room due to the brake master cylinder. Think RX-3 engine bay.
These are right hand drive, but they're similar to what mine looks like.
http://au.f2.pg.photos.yahoo.com/ph/...bum?.dir=/d184
http://www.hitman.hm/toy12a.htm
If the carb won't work, I'll have to go with a megasquirt I suppose. Someone will probably need to fab me up a secondary fuel rail because the stocker is way too long. Or I could try an Atkins 20B 9" SC manifold (no SC) and my Edlebrock. I was affraid the front rotor would go lean under acceleration, so that's why I'm going to try the stock upper and lower manifolds first. An SC would be nice, but it's like $3000. Heh, I can't even afford a megasquirt right now.
05-11-04, 03:01 AM
#21
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Originally posted by $150FC
Great stuff, Ted.
Is this with the stock 20B UIM + LIM?
Great stuff, Ted.
Is this with the stock 20B UIM + LIM?
We've got a getto adapter right in front of the TB with the too-small air filter slapped on it right now.
TB does have the "TB mod" on it.
TB is not "smoothed" yet.
Custom header was built and welded by the owner.
It hasn't cracked yet! *cross fingers*
There's pics down in another thread.
-Ted
05-11-04, 03:04 AM
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Originally posted by t-von
Ted when you say Stock Stock engine, do you mean a stock rebuild or an engine what went from the crate to the engine bay?
Ted when you say Stock Stock engine, do you mean a stock rebuild or an engine what went from the crate to the engine bay?
It's starting to smoke oil out the exhaust, so I think the oil control rings are finally starting to show some signs of wear.
The engine *is* going to get ported and rebuild prior to the going turbos.
I think shooting for 600 minimum hp to the ground...it would be nice to be safe and get the engine refreshed for tripling it's output.
-Ted
05-11-04, 11:18 AM
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Originally posted by RETed
Yep, stock from the throttle body to exhaust port.
We've got a getto adapter right in front of the TB with the too-small air filter slapped on it right now.
TB does have the "TB mod" on it.
TB is not "smoothed" yet.
Custom header was built and welded by the owner.
It hasn't cracked yet! *cross fingers*
There's pics down in another thread.
-Ted
Yep, stock from the throttle body to exhaust port.
We've got a getto adapter right in front of the TB with the too-small air filter slapped on it right now.
TB does have the "TB mod" on it.
TB is not "smoothed" yet.
Custom header was built and welded by the owner.
It hasn't cracked yet! *cross fingers*
There's pics down in another thread.
-Ted
05-12-04, 04:06 AM
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Originally posted by RETed
Total bone-stock, never been opened, never been rebuilt...
It's starting to smoke oil out the exhaust, so I think the oil control rings are finally starting to show some signs of wear.
The engine *is* going to get ported and rebuild prior to the going turbos.
I think shooting for 600 minimum hp to the ground...it would be nice to be safe and get the engine refreshed for tripling it's output.
-Ted
Total bone-stock, never been opened, never been rebuilt...
It's starting to smoke oil out the exhaust, so I think the oil control rings are finally starting to show some signs of wear.
The engine *is* going to get ported and rebuild prior to the going turbos.
I think shooting for 600 minimum hp to the ground...it would be nice to be safe and get the engine refreshed for tripling it's output.
-Ted
you definitely have to get soundclips of it after it gets ported.