so far I got my car pretty dialed in thanks to Pete and his base tune. I got the afr's looking good just need help with the timing which I have no idea what i'm doing and since I live on Maui I'm limited in my options for dyno tuning. one dyno and they are honda guys.
My question is what should I look for timing wise and whats the best way to fine tune without doing damage?
Here's where I'm at now.
sr20det
FP Big28
555cc
z32 maf
stock fpr
fmic
tuning my sr
Moderator: Matt
tuning my sr
- Attachments
-
- sr20det-test-open-loop.bin
- (32 KiB) Downloaded 302 times
Hey Josh,
Good to hear that you've got her all up and running.
Your question about timing is one that has a myriad of answers. Everyone has their own way of doing it. And it basically comes down to knock detection.
Where you engine begins to knock will depend on many things. The main ones being the octane level of your fuel, your boost level, ambient temperature and lastly of course, IGN timing.
You'll soon realise that the only cells that really matter will be in a line on the right side of the map from about 3000 rpm onwards. A bit like this trace but usually over to the right a bit more:
http://www.plmsdevelopments.com/files/s ... 25_afm.jpg
Now back to knock detection. This is the hard bit. Up to about 3500 I've found that you can hear it pretty easily. Above that things get hard cos it's difficult to tell the difference between knock and mechanical noise.
Here's where all the different techniques come in. Some guys swear by "Brand X" electronic detonation detection (a local guy uses a "TXS Tuner Pro" WB AFR + inbuilt knock sensing - Google it...). Some use a simple electronic listening device such as "Steelmen Chassis Ears". I even know of one guy (prominent tuner) who uses a piece of hose between his ear and the engine. Swears by it!
Whatever way you do it usually requires a good deal of practice before you can confidently find the knock limit. Once you find it you generally take a couple degrees timing out as a safety factor. If it's a track car you take out a bit more....
I'd be very interested to hear from other guys as to what knock detection works best for them.
PL
Good to hear that you've got her all up and running.
Your question about timing is one that has a myriad of answers. Everyone has their own way of doing it. And it basically comes down to knock detection.
Where you engine begins to knock will depend on many things. The main ones being the octane level of your fuel, your boost level, ambient temperature and lastly of course, IGN timing.
You'll soon realise that the only cells that really matter will be in a line on the right side of the map from about 3000 rpm onwards. A bit like this trace but usually over to the right a bit more:
http://www.plmsdevelopments.com/files/s ... 25_afm.jpg
Now back to knock detection. This is the hard bit. Up to about 3500 I've found that you can hear it pretty easily. Above that things get hard cos it's difficult to tell the difference between knock and mechanical noise.
Here's where all the different techniques come in. Some guys swear by "Brand X" electronic detonation detection (a local guy uses a "TXS Tuner Pro" WB AFR + inbuilt knock sensing - Google it...). Some use a simple electronic listening device such as "Steelmen Chassis Ears". I even know of one guy (prominent tuner) who uses a piece of hose between his ear and the engine. Swears by it!
Whatever way you do it usually requires a good deal of practice before you can confidently find the knock limit. Once you find it you generally take a couple degrees timing out as a safety factor. If it's a track car you take out a bit more....
I'd be very interested to hear from other guys as to what knock detection works best for them.
PL
I tend to bolt a knock sensor to the engine and run this through a commercial style mike processor:
http://www.behringer.com/VX2496/index.cfm?lang=eng
Its a bit OTT, but engines can get very loud so I make use of its built in limiting/filtering etc to help save my ears!!
If I am using a car I am very familiar with i.e. RNN14 typically now I just know what will be safe or not for a normal tune road car.
Ed
http://www.behringer.com/VX2496/index.cfm?lang=eng
Its a bit OTT, but engines can get very loud so I make use of its built in limiting/filtering etc to help save my ears!!
If I am using a car I am very familiar with i.e. RNN14 typically now I just know what will be safe or not for a normal tune road car.
Ed
As long as you can access a dyno then you can just gradually increase timing until torque stops increasing. This is the point where detonation is starting to happen. Then you add a safety factor by removing timing. Take a few degrees out before you do any of this. In fact if you're running 18psi take a couple degrees out in the last 4 columns right now!
This is not for the faint hearted though. Run your SR on the detonation threshold for very long and you'll hurt it.
You'll get away with 18psi for a little while. Just don't email me saying "my engine's making a funny noise"!
Although I'm always interested to see pictures of blown head gaskets, cracked ring lands and hammered big-end bearings!
PL
This is not for the faint hearted though. Run your SR on the detonation threshold for very long and you'll hurt it.
You'll get away with 18psi for a little while. Just don't email me saying "my engine's making a funny noise"!
Although I'm always interested to see pictures of blown head gaskets, cracked ring lands and hammered big-end bearings!
PL
Decrease the numbers.
If by ROM tunes you mean guys who just buy chips off of eBay and slap them in then it's a case of "some do and some don't". If the maps are really conservative then they should be fine - but gains will be minimal. If the tune is "closer to the edge" then it will only take something like a lazy fuel pump, dirty AFM or incorrect base timing to bring on detonation.
"Mail order tunes" can be done (I've done lots) but you need to make sure that the customer understands the process and that they get their AFR's checked.
PL
If by ROM tunes you mean guys who just buy chips off of eBay and slap them in then it's a case of "some do and some don't". If the maps are really conservative then they should be fine - but gains will be minimal. If the tune is "closer to the edge" then it will only take something like a lazy fuel pump, dirty AFM or incorrect base timing to bring on detonation.
"Mail order tunes" can be done (I've done lots) but you need to make sure that the customer understands the process and that they get their AFR's checked.
PL
I understand now. I'm new to the world of tuning and trying to learn. Luckily I have you guys to answer my questions and keep me from blowing my motor.
what do you think of this?
http://www.msdignition.com/tool_8.htm
what do you think of this?
http://www.msdignition.com/tool_8.htm
here's one that looks promising.
http://www.turboxs.com/more_info.php?ID=212
from what I've found the subaru guys have had good luck with it. $97US
If the stock sensor is useless how about this.
http://buy1.snapon.com/catalog/item.asp ... up_ID=1412
http://www.turboxs.com/more_info.php?ID=212
from what I've found the subaru guys have had good luck with it. $97US
If the stock sensor is useless how about this.
http://buy1.snapon.com/catalog/item.asp ... up_ID=1412
I'm actually considering one of those TXS knock lites myself. The key to electronic knock detection is to firstly understand that it's hard to discriminate between engine mechanical noise and knock. And also that engine mechanical noise varies with RPM. So you need something that takes this into account. The Knocklite appears to do this according to their blurb:
"The task of filtering out the noise is no simple task as the level of engine noise changes with RPM. Thus for a knock detection system it is important to be able to vary the sensitivity over RPM. If you only have one setting then the knock detection will be sensitive to knock at high engine noise (high rpm) but there will be a reduced sensitivity at low RPM."
I intend to use one of these with the factory sensor. I've made up a "tee piece" so I can just plug into the knock sensor on any SR - and still have the signal going to the factory ECU.
PL
"The task of filtering out the noise is no simple task as the level of engine noise changes with RPM. Thus for a knock detection system it is important to be able to vary the sensitivity over RPM. If you only have one setting then the knock detection will be sensitive to knock at high engine noise (high rpm) but there will be a reduced sensitivity at low RPM."
I intend to use one of these with the factory sensor. I've made up a "tee piece" so I can just plug into the knock sensor on any SR - and still have the signal going to the factory ECU.
PL