Monsterbox's 20b FD3S Conversion
03-26-15, 08:28 AM
#476
Spoke with Addicted yesterday and looks like they resolved the issue! These guys are on top of the game. Seriously, if anyone needs rotary work around the Tenn/Alabama/Georgia area, these are your guys!
They removed the return line off the regulator and let it dump into a bucket when the fuel began to act up. Doing so immediately resolved the issue! A larger return line was installed and it seems to be fixed. It appears that the difference in size between the feed and smaller return was causing high pressure / aeration into the tank which leads to the cavitation/heat cycle. I know some folks had mentioned this earlier, never thought this was possible as there was no issues with factory feed/return but learn something new every day! It makes sense now that if the feed flows considerably more than the return, the fuel is going to have high back pressure at the regulator/return
Fuel pressure is reportedly higher and now the primary pump is providing considerably more fuel. Hopefully it passes the endurance test and we get some numbers today!
If anyone is going to Import Alliance at Atlanta Motorspeedway, I'm hoping to be there this weekend lets meet up!
They removed the return line off the regulator and let it dump into a bucket when the fuel began to act up. Doing so immediately resolved the issue! A larger return line was installed and it seems to be fixed. It appears that the difference in size between the feed and smaller return was causing high pressure / aeration into the tank which leads to the cavitation/heat cycle. I know some folks had mentioned this earlier, never thought this was possible as there was no issues with factory feed/return but learn something new every day! It makes sense now that if the feed flows considerably more than the return, the fuel is going to have high back pressure at the regulator/return
Fuel pressure is reportedly higher and now the primary pump is providing considerably more fuel. Hopefully it passes the endurance test and we get some numbers today!
If anyone is going to Import Alliance at Atlanta Motorspeedway, I'm hoping to be there this weekend lets meet up!
Last edited by Monsterbox; 03-26-15 at 10:35 AM.
03-26-15, 10:01 AM
#477
talking head
i think i win 100 internets everytime with that old chestnut "same size" argument for fuel return sizing on bypass reg setups
but alas i thinks i already banned the wingnut who used to argue me down on this point
it has been quite a journey this 20b conversion and you took on all the hurdles without spitting the dummy publicly , and proved a few truths ( the hard way ) along the way
congrats.. enjoy
but alas i thinks i already banned the wingnut who used to argue me down on this point
it has been quite a journey this 20b conversion and you took on all the hurdles without spitting the dummy publicly , and proved a few truths ( the hard way ) along the way
congrats.. enjoy
03-26-15, 10:32 AM
#478
i think i win 100 internets everytime with that old chestnut "same size" argument for fuel return sizing on bypass reg setups
but alas i thinks i already banned the wingnut who used to argue me down on this point
it has been quite a journey this 20b conversion and you took on all the hurdles without spitting the dummy publicly , and proved a few truths ( the hard way ) along the way
congrats.. enjoy
but alas i thinks i already banned the wingnut who used to argue me down on this point
it has been quite a journey this 20b conversion and you took on all the hurdles without spitting the dummy publicly , and proved a few truths ( the hard way ) along the way
congrats.. enjoy
20b "aka" Murphy's Law - Anything that can go wrong, will. And hopefully all possible mistakes have now been made
I admit I'm as hardheaded as they come. But hey, learning the hard way is learning the best way!
03-27-15, 12:53 PM
#481
Hey, I've been having similar problems with my fuel pressure. I added pulsation dampeners which helped a little, but that just treated the symptom not the actual cause. I was about to throw a new fuel pressure regulator at it. I had suspected that my return line may be sized too small, but the CJ assembly that holds my 2 044s comes with a -6an return. So I guess I need to pull the assembly and have a -8AN return tig welded into it?
It's also interesting that I get these fluctuations when running only 1 fuel pump
It's also interesting that I get these fluctuations when running only 1 fuel pump
03-27-15, 10:50 PM
#482
Quick post. Detailed to follow.
488rwhp @ 8psi
550@ 10psi
627hp / 458tq @ 16psi pump and meth
727hp / 575ftlbs @ 20psi pump/meth
Spinning so bad on dyno. First pass at 20psi 666hp. Two people in trunk, 727hp still spinning couldnt read accurate chart so decided it was enough :P
Waiting to resolve a blip in the map at injector staging but surely will be fixed
Will post vids and pics soon
Thank you to everyone who has participated in this build. This community is a great place. Without the inspirations and open support this would have never been possible.
488rwhp @ 8psi
550@ 10psi
627hp / 458tq @ 16psi pump and meth
727hp / 575ftlbs @ 20psi pump/meth
Spinning so bad on dyno. First pass at 20psi 666hp. Two people in trunk, 727hp still spinning couldnt read accurate chart so decided it was enough :P
Waiting to resolve a blip in the map at injector staging but surely will be fixed
Will post vids and pics soon
Thank you to everyone who has participated in this build. This community is a great place. Without the inspirations and open support this would have never been possible.
03-28-15, 05:22 AM
#485
talking head
congrats
my little tip for street mode is to pull 1 or 2 degrees from the timing trims so you dont run on the sharp edge
.. this will just ease in some safety margin for glitches in fuel quality , and changes in vehicle load
( passengers or hills ( or both ) and hot days and very cool ones )
and has relatively minor effect on the power curves
i then usually put that degree back into the idle maps so there is no decrease in idle quality
going back to the sharp tune ( for when fuel quality and engine load is assured ) requires only to re-zero the timing trim ( and pull that idle degree back, though not always necessary )
.. if the ecu has multiple saved maps , then you should copy this one entirely to another slot, and pull that degree from there . careful to select street or race tunes as required
my little tip for street mode is to pull 1 or 2 degrees from the timing trims so you dont run on the sharp edge
.. this will just ease in some safety margin for glitches in fuel quality , and changes in vehicle load
( passengers or hills ( or both ) and hot days and very cool ones )
and has relatively minor effect on the power curves
i then usually put that degree back into the idle maps so there is no decrease in idle quality
going back to the sharp tune ( for when fuel quality and engine load is assured ) requires only to re-zero the timing trim ( and pull that idle degree back, though not always necessary )
.. if the ecu has multiple saved maps , then you should copy this one entirely to another slot, and pull that degree from there . careful to select street or race tunes as required
Last edited by bumpstart; 03-28-15 at 05:24 AM.
03-28-15, 09:43 AM
#488
^ spin
Videos soon and hopefully some footage from IA.
I can't express it enough. This community, rx7club specifically, has been a source of information and motivation for the past 10 years. Feel like this car was built by everyone. Influenced by the 20b's that came before. Thank you.
Lets see if we can wrap this up and get this thing on the road!
Last edited by Monsterbox; 03-28-15 at 09:45 AM.
03-28-15, 10:26 AM
#490
Looks like you are running way too rich from 3200-4200, then way too lean from 5000-5700 at low boost. High boost is not showing the AFRs, but that big dip at 5700 is a cause for concern if it correlates to the same lean area at low boost.
Is this a load bearing Dynojet?
Spinning the tires on the dyno, means you will never get to redline on the street, start saving for wider wheels and rear flares. Welcome to my world.
Is this a load bearing Dynojet?
Spinning the tires on the dyno, means you will never get to redline on the street, start saving for wider wheels and rear flares. Welcome to my world.
03-28-15, 07:03 PM
#491
Spoke with Addicted yesterday and looks like they resolved the issue! These guys are on top of the game. Seriously, if anyone needs rotary work around the Tenn/Alabama/Georgia area, these are your guys!
They removed the return line off the regulator and let it dump into a bucket when the fuel began to act up. Doing so immediately resolved the issue! A larger return line was installed and it seems to be fixed. It appears that the difference in size between the feed and smaller return was causing high pressure / aeration into the tank which leads to the cavitation/heat cycle. I know some folks had mentioned this earlier, never thought this was possible as there was no issues with factory feed/return but learn something new every day! It makes sense now that if the feed flows considerably more than the return, the fuel is going to have high back pressure at the regulator/return
Fuel pressure is reportedly higher and now the primary pump is providing considerably more fuel. Hopefully it passes the endurance test and we get some numbers today!
If anyone is going to Import Alliance at Atlanta Motorspeedway, I'm hoping to be there this weekend lets meet up!
They removed the return line off the regulator and let it dump into a bucket when the fuel began to act up. Doing so immediately resolved the issue! A larger return line was installed and it seems to be fixed. It appears that the difference in size between the feed and smaller return was causing high pressure / aeration into the tank which leads to the cavitation/heat cycle. I know some folks had mentioned this earlier, never thought this was possible as there was no issues with factory feed/return but learn something new every day! It makes sense now that if the feed flows considerably more than the return, the fuel is going to have high back pressure at the regulator/return
Fuel pressure is reportedly higher and now the primary pump is providing considerably more fuel. Hopefully it passes the endurance test and we get some numbers today!
If anyone is going to Import Alliance at Atlanta Motorspeedway, I'm hoping to be there this weekend lets meet up!
Last edited by t-von; 03-28-15 at 07:06 PM.
03-29-15, 02:58 AM
#492
Thx for sharing this info because now I know what my problem was when I was running my surge tank. My external Bosch 044 would always hum after a few minutes and gave me hard hot starting issues. My surge tank has the stock pump feeding it with stock sized lines with also having stock lines on the return side from the surge tank. The 044 feeds through the stock lines to the primary rail. The return from my pressure regulator is also the stock line back to the surge tank. I know now that my problem is the stock return line from the surge tank to the main fuel tank as it's too small to return the excessive fuel from both pumps from the surge tank. The hard hot start and humming issue is the reason I removed that surge tack a few months ago. Now I have a reason to retry the setup.
YES!!!! Awesome. Hope you can fix it.
03-29-15, 03:00 AM
#493
Looks like you are running way too rich from 3200-4200, then way too lean from 5000-5700 at low boost. High boost is not showing the AFRs, but that big dip at 5700 is a cause for concern if it correlates to the same lean area at low boost.
Is this a load bearing Dynojet?
Spinning the tires on the dyno, means you will never get to redline on the street, start saving for wider wheels and rear flares. Welcome to my world.
Is this a load bearing Dynojet?
Spinning the tires on the dyno, means you will never get to redline on the street, start saving for wider wheels and rear flares. Welcome to my world.
Dont plan to run more than 12-16psi anyhow it seems like it will be more than enough
Im going to go over chart with tuner. Youre right, that 12.0afr range area seems sketchy.
Last edited by Monsterbox; 03-29-15 at 03:13 AM.
04-27-15, 09:23 AM
#500
I am aware of this, and asked Zach multiple times to send me the ecu file and logs. Until yesterday I have only recieved a log. I have had a running joke around here for 10 plus years that "it must be the ecu". I find people who cant figure out the problems always point towards something they do not understand. Being turbo has nothing to do with how the ecu operates. Injector staging works fine on the other 20B.
