Tuning without dyno. !! [Archive]

Kirk Feldkamp

04-06-2010, 07:23 PM

You will be able to calibrate the engine to a set of parameters (AFR/lambda, an ignition map, etc), but you will really have no idea what's happening within the system. I was blown away by the automatic tuning capability of the MegaSquirt on a car I'm involved with, but again, you don't really know if what you have tuned the system to is "optimal" in any regard. Dynos are simply a way to repeatably and reliably simulate loading conditions for the engine. Once you're able to do that it's possible to understand the effects of the changes you make on the system. Are your lambda targets reasonable? Is your ignition map anywhere close to minimum best timing (MBT)? If those two things are far enough off, you can easily hurt your engine, or miss out on a huge amount of performance. If you do some reading about these areas and understand where you should start, then you can probably get a reasonable calibration without a dyno. As soon as you want to start looking at improving your system, you're going to need a dyno.

-Kirk

Mikey Antonakakis

04-06-2010, 08:58 PM

Call some places with chassis dynos in the area, they are usually happy to help out with cost or donate time. You get their name out and they get to be involved in a cool project. We've had pretty good luck with that. Just make sure you can at least drive around a little bit with the tune you have, that way you don't waste their time at the dyno (we've made that mistake).

mech5107

04-07-2010, 04:04 AM

First you have to tune it a bit on the road and then on a chassis dyno, if you don't have your own dyno.
Yes you can run safely on the event with a road tune, but not full potential.

Ignition-Kid

04-07-2010, 04:28 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by kira_vtec:
Yes, it's possible and not hard with a AFR, TPS, MAP and RPM data acquisition. But it's better if you do this on dyno and them some fine tuning on track. Do you have any ignition timimg map for your engine? </div></BLOCKQUOTE>

I have a brand new 2009 Honda cbr600rr engine , A PE stand alone Ecu, And i am planning to use the base map on the PE website to start with, We don't have dynos here in Egypt, We can't afford buying a wide-band O2 senor and a controller at the moment, I just need a stable, moderate engine performance, And i guess from your replies guys that it is a possible thing to do.

Mikey Antonakakis

04-07-2010, 05:16 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ignition-Kid:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by kira_vtec:
Yes, it's possible and not hard with a AFR, TPS, MAP and RPM data acquisition. But it's better if you do this on dyno and them some fine tuning on track. Do you have any ignition timimg map for your engine? </div></BLOCKQUOTE>

I have a brand new 2009 Honda cbr600rr engine , A PE stand alone Ecu, And i am planning to use the base map on the PE website to start with, We don't have dynos here in Egypt, We can't afford buying a wide-band O2 senor and a controller at the moment, I just need a stable, moderate engine performance, And i guess from your replies guys that it is a possible thing to do. </div></BLOCKQUOTE>
I hope you have a good sense of smell and can read plugs well if you hope to get a decent tune without any O2 sensor.

Ignition-Kid

04-07-2010, 05:29 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mikey Antonakakis:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ignition-Kid:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by kira_vtec:
Yes, it's possible and not hard with a AFR, TPS, MAP and RPM data acquisition. But it's better if you do this on dyno and them some fine tuning on track. Do you have any ignition timimg map for your engine? </div></BLOCKQUOTE>

I have a brand new 2009 Honda cbr600rr engine , A PE stand alone Ecu, And i am planning to use the base map on the PE website to start with, We don't have dynos here in Egypt, We can't afford buying a wide-band O2 senor and a controller at the moment, I just need a stable, moderate engine performance, And i guess from your replies guys that it is a possible thing to do. </div></BLOCKQUOTE>
I hope you have a good sense of smell and can read plugs well if you hope to get a decent tune without any O2 sensor. </div></BLOCKQUOTE>

I have the Stock O2 sensor !!

RollingCamel

04-07-2010, 05:35 PM

Aha, at last you got your engine. Mabrouk!

Ignition-Kid

04-07-2010, 05:40 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RollingCamel:
Aha, at last you got your engine. Mabrouk! </div></BLOCKQUOTE>

Thanks,Appreciate it !

Ockham

04-07-2010, 07:16 PM

If you don't have access to a wide-band AFR sensor for tuning, then you're in dangerous territory. Sounds like you don't have easy access to a backup engine, either.

I'm not sure what kind of O2 sensors come with the bike (Bike Bandit's pics are pretty low-resolution), but I doubt they're wide-band. From what I was able to find, they're heated, which is a good sign, but most wide-band O2 sensors are five-wire designs, instead of the stock sensors' 4 wires each. It's possible to determine the stock pin assignments, but you still need a controller compatible with them, unless you can access the values it reads within Honda's ECU, which isn't realistically possible unless you're a dealer.

You guys are probably on a stiff budget, but wide-band AFR sensors are getting really cheap. You can probably find a retailer who will ship one internationally without any trouble. NGK markets their Powerdex AFX sensor and display for 250USD, and if you're really lucky, you might be able to get a unit or two sponsored.

If you can't get your hands on the right sensor, you'll have to rely on imprecise methods. Individual cylinder temperature monitoring is your next best bet. Basically, temperature probes installed in the exhaust streams near the cylinder head will show you how even combustion is across your cylinders, but that doesn't tell you much about the AFR. If you're at a university, there's a good chance someone has a set of thermocouples around, and you can read them with a DMM and the right adapter, a laptop, or a standalone display. After that, it's "plug tuning," which involves "reading" the spark plugs to provide broad estimates about combustion. That's a subtle, dangerous endeavor which requires extensive experience and is better suited to carburetion, so I'd only get into it if you have no other options.

Powerdex AFX. (http://sparkplugs.com/results_cross.asp?pid=91101) http://sparkplugs.com/results_cross.asp?pid=91101

JamesWolak

04-08-2010, 10:09 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ignition-Kid:

I have a brand new 2009 Honda cbr600rr engine , A PE stand alone Ecu, And i am planning to use the base map on the PE website to start with, We don't have dynos here in Egypt, We can't afford buying a wide-band O2 senor and a controller at the moment, I just need a stable, moderate engine performance, And i guess from your replies guys that it is a possible thing to do. </div></BLOCKQUOTE>

I think you misunderstood. We said you could calibrate a motor to have "stable, moderate engine performance" without a dyno. Not without a wide-band.

You need to find a way to get a hold of a wide band 02 sensor. You can only make poor guesses without them.

Side note:
I love that I bitch about not having in cylinder pressure transducers but there are teams without wide bands. It really brings me back to reality. I couldn't image calibrating like you have to Ignition-Kid. The best of luck to you.

Kirk Feldkamp

04-08-2010, 12:18 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JamesWolak:
You need to find a way to get a hold of a wide band 02 sensor. You can only make poor guesses without them. </div></BLOCKQUOTE>

TRUTH!

I got a brand new Innovate LC-1 (with sensor included) for $156 on eBay the other day. They're usually around $200 retail. Think of the opportunity costs involved, Ignition-Kid. Your cost to rebuild or replace the engine is *much* more than the cost of the wideband controller and sensor. More importantly, your calibration is going to be very difficult to do *well* without a wideband O2 sensor, if not impossible. Without the experience or the proper tools, it is *highly* likely you will hurt the engine, not get a good tune at all, or both.

-Kirk

RollingCamel

04-08-2010, 03:31 PM

Same goes for piggy-back tuning?

Ignition-Kid

04-08-2010, 05:06 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JamesWolak:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ignition-Kid:

I have a brand new 2009 Honda cbr600rr engine , A PE stand alone Ecu, And i am planning to use the base map on the PE website to start with, We don't have dynos here in Egypt, We can't afford buying a wide-band O2 senor and a controller at the moment, I just need a stable, moderate engine performance, And i guess from your replies guys that it is a possible thing to do. </div></BLOCKQUOTE>

I think you misunderstood. We said you could calibrate a motor to have "stable, moderate engine performance" without a dyno. Not without a wide-band.

You need to find a way to get a hold of a wide band 02 sensor. You can only make poor guesses without them.

Side note:
I love that I bitch about not having in cylinder pressure transducers but there are teams without wide bands. It really brings me back to reality. I couldn't image calibrating like you have to Ignition-Kid. The best of luck to you. </div></BLOCKQUOTE>

This will really hurt our budget, but i will try my best to get one soon, Thank you James !

Ignition-Kid

04-08-2010, 05:08 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kirk Feldkamp:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JamesWolak:
You need to find a way to get a hold of a wide band 02 sensor. You can only make poor guesses without them. </div></BLOCKQUOTE>

TRUTH!

I got a brand new Innovate LC-1 (with sensor included) for $156 on eBay the other day. They're usually around $200 retail. Think of the opportunity costs involved, Ignition-Kid. Your cost to rebuild or replace the engine is *much* more than the cost of the wideband controller and sensor. More importantly, your calibration is going to be very difficult to do *well* without a wideband O2 sensor, if not impossible. Without the experience or the proper tools, it is *highly* likely you will hurt the engine, not get a good tune at all, or both.

-Kirk </div></BLOCKQUOTE>

Yeah, You are right, I guess we will go with the LC-1, Appreciate your reply Kirk !

JamesWolak

04-09-2010, 07:21 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RollingCamel:
Same goes for piggy-back tuning? </div></BLOCKQUOTE>

Yes.

mech5107

04-09-2010, 08:00 AM

We also use the lc1 for engine tunning.

Great device, can give both wideband and narrowband signal (for close loop usage) and calibrated to whatever output you what using the rs232 kit.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JamesWolak:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RollingCamel:
Same goes for piggy-back tuning? </div></BLOCKQUOTE>

Yes. </div></BLOCKQUOTE>

Generally yes, but you are in a totally different situation than with the stand-alone systems. A least you have something to start.

Also, i think that a basic map for cbr600 is available from PE. This will help a lot.

JamesWolak

04-09-2010, 08:14 AM

Trying to calibrate without a wideband is like trying to build a chassis without any measuring devices. You can do it but it's going to be wrong.

With a piggyback, standalone, or even a carburetor you should have a wideband.

How are you going to make any fueling changes otherwise?

B Lewis @ PE Engine Management

04-09-2010, 09:50 AM

You know, back in the dark ages all tuning was done without a wideband http://fsae.com/groupee_common/emoticons/icon_smile.gif It is possible.

We are currently tuning a very small single cylinder aiplane engine without the use of our wideband because of size and packaging issues.

Also, I have seen some crazy tuning on these restricted 600cc engines over the years and my experience is that unless you have made internal modifications, run forced induction or have oil starvation problems they are virtually bullet proof. It is not easy to damage the engine just by having an incorrect tune.

BuckeyeEngines

04-09-2010, 10:02 AM

I agree that tuning can be acheived without a wideband, however this would be done by someone with lots of experience. With too much ignition timing it is easy to cause ireperable damage to the engine.

Kirk Feldkamp

04-09-2010, 03:11 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ignition-Kid:
This will really hurt our budget, but i will try my best to get one soon... </div></BLOCKQUOTE>

If this is going to be a dealbreaker on your budget, FSAE might not be a great idea! http://fsae.com/groupee_common/emoticons/icon_wink.gif

-Kirk

Ignition-Kid

04-10-2010, 12:51 PM

Wesley

04-10-2010, 01:42 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BuckeyeEngines:
I agree that tuning can be acheived without a wideband, however this would be done by someone with lots of experience. With too much ignition timing it is easy to cause ireperable damage to the engine. </div></BLOCKQUOTE>

Eh, the PE maxes out at 50 degrees, so you're not going to destroy it. We've run it with the trigger wheel off a tooth, and the worst we've experienced was red-hot headers (retarded,) and on the other side, really low power (advanced)

That engine still runs 3 years later.

Yellow Ranger

04-10-2010, 05:03 PM

And if I remember correctly Wes, pretty damn good for non-dyno tune.

Ockham

04-11-2010, 08:11 PM

Brian, I would normally defer to your expertise when it comes to these matters, but I'm with Buckeye here. A team in Egypt will have serious problems securing a replacement if they nuke an engine; better to err way on the side of caution. The first time you tune an engine, it should either be under the wing of a master, or with every technological aid (and an understanding of same) you can lay hands on.

Ignition-Kid

04-12-2010, 01:24 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ockham:
Brian, I would normally defer to your expertise when it comes to these matters, but I'm with Buckeye here. A team in Egypt will have serious problems securing a replacement if they nuke an engine; better to err way on the side of caution. The first time you tune an engine, it should either be under the wing of a master, or with every technological aid (and an understanding of same) you can lay hands on. </div></BLOCKQUOTE>

Actually We have two engines ( Brand New ), we bought like 4 books from amazon.com ( For the tuning process only ), Got our LC-1, We are doing our best to Reach our Goal http://fsae.com/groupee_common/emoticons/icon_wink.gif !

Ockham

04-12-2010, 06:47 AM

Sounds like you guys know what you're doing, first-timers or not. Good to hear. http://fsae.com/groupee_common/emoticons/icon_smile.gif

Pradeep

04-12-2010, 01:27 PM

We're running a Honda CBR 600RR (2006) on the PE ECU with a 35mm throttle body bore, semi-sequential injection and wasted spark ignition.

We've bought Innovate's LC-1 kit, we've been tuning for a while now. I've read the books on engine tuning by Greg Banish and Dave Walker. However we still haven't been able to get our engine past 7500 rpm.
I think it might be because the ignition timing we are running is too far advanced but when I retard I get a lot of back fire in the exhaust.
There is also have backfire in our intake manifold from time to time and our MAP sensor is malfunctioning currently. However we're using TPS as load and we've selected the "No MAP sensor" option in the sensor setup. Also could the MAP sensor have been affected by the backfire in the intake?

I've posted the fuel and ignition maps here because I really want to know if I'm somewhere in the ballpark. On this map the engine is going up to 7500 rpm even at low throttle percentage (30%) which also makes me wonder if the 35mm throttle bore is too large.

Yesterday my lambda sensor started showing very very lean values even when the engine was running well. I don't have another lambda right now and a new one will take atleast a week to arrive. Do lambdas get spoilt easily? It's been used for only a couple of months although the mixtures were quite rich.
http://i41.tinypic.com/2lvhetl.jpg
http://i44.tinypic.com/6zavly.jpg

Thanks

Ignition-Kid

04-12-2010, 04:40 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ockham:
Sounds like you guys know what you're doing, first-timers or not. Good to hear. http://fsae.com/groupee_common/emoticons/icon_smile.gif </div></BLOCKQUOTE>

Thanks Ockham http://fsae.com/groupee_common/emoticons/icon_smile.gif

BuckeyeEngines

04-13-2010, 07:10 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wesley:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BuckeyeEngines:
I agree that tuning can be acheived without a wideband, however this would be done by someone with lots of experience. With too much ignition timing it is easy to cause ireperable damage to the engine. </div></BLOCKQUOTE>

Eh, the PE maxes out at 50 degrees, so you're not going to destroy it. We've run it with the trigger wheel off a tooth, and the worst we've experienced was red-hot headers (retarded,) and on the other side, really low power (advanced)

That engine still runs 3 years later. </div></BLOCKQUOTE>

Not if you make your own trigger wheel to essentially "trick" the PE. We can get 70 Deg. I figured everyone did something like this. Obviously this will be highly dictated by your intake design but usually 55 to 60 deg advance is the most we run, But by putting 50 into the ignition map for PE we get 70.

You are right though, 50 degrees advance should not cause harm especially without raising in clyinder pressure by means of pistons, decking the head, turbo or what have you.

BuckeyeEngines

04-13-2010, 07:21 AM

I did not read all of the posts before posting last.

Ignition kid. I would still be careful, two engiens isnt that many. We have 4 running engines and 2 that could be put together. Before I was in charge the team leader killed two engines in a week. Simple mistakes, not having the wrist pins fit to custom made pistons in one case caused a rod failure, and not putting a holder for the oil pressure regulator in a custom oil pan for the other engine.

Moral of the story be carful with your engines, one small mistake is all it takes at 12K rpm. I like the chassis team, you screw something up it just takes time to grind it out and re weld. As engine guys we dont have the luxury.

Good luck with your tuning,

TorqueWrench

04-13-2010, 07:51 AM

+1 to what Branden said

Tuning is one of those places to take your time. My school only has 1 engine, no dyno and no money for a complete replacement, so I know how it feels to be in your spot. Its good you have a wideband, thing is a godsend when it comes down to doing fuel. Spark is tricky without a dyno, but most ECUs have an auto-tune that will get you within 10%.

Make sure all your sensors are calibrated, make sure all your timing is right (or as right as you think it should be) and that you have fuel using a check light before plugging coils and injectors in. Its true that there really is no forgiveness in the engine region, any little mistake during assembly or forgetting to replace a part with a new one when its lifespan is up tends to lead to bad things. To be honest it doesn't matter what speed its at, its still going to go wrong.

We all make mistakes and the important part is to learn from it. The engine leader before me blew a hole straight through a piston once. I forgot to double check a spacer when switching rocker arms and bent a pushrod within 2 months of taking over. No team, especially a new one, should expect their student leader to know everything and be perfect right away. Competitions about learning and the quickest way to do so is to mess up sometimes. It just isnt a very cost effective way of doing it.

Good luck with your tuning.

Pradeep

04-13-2010, 09:06 AM

My post just came up after approval by the moderator.

Kirk Feldkamp

04-13-2010, 09:49 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Pradeep:

Yesterday my lambda sensor started showing very very lean values even when the engine was running well. ... It's been used for only a couple of months although the mixtures were quite rich. </div></BLOCKQUOTE>

Rich misfires will indicate as very lean on an oxygen sensor. Remember, the sensor is measuring the oxygen content of the exhaust gas, not the fuel content. In other words, if you've got so much fuel that you can't get the mixture to ignite, it will actually show lean because none of the oxygen is being used for combustion. In my experience, if this is your problem, your eyes will also be burning from all the fuel going out the tailpipe. What lambda (or AFR) are you tuning to? At full load on a naturally aspirated engine, a lambda of .88 (AFR of ~12.9) is a good [safe] place to start. Any richer than this and you're probably actually hurting performance. If you're really going for max power and max fuel economy, you can push that lambda up to .90 to .92 (AFR 13.2-13.5). The combustion chambers in most sportbikes are pretty tolerant to leaner mixtures like this, but you still need to be very careful. Paying close attention to your lambdas, ignition advance, and spark plug reading are very important if you want to keep your engine in good health.

-Kirk

Wesley

04-13-2010, 10:36 AM

With stock injectors, your pulsewidths look a lot on the large side in the upper ranges.

Verify with absolute certainty that your trigger wheel is on correctly, retarded timing can also compound the effect of a slow-burning rich flame and read lean due to the late and slow burn. Try advancing all your timing by about 15 degrees and lean your map out to peak at about 2.6-2.8ms pulsewidths (@ 52 psi) and see where that gets you. If it runs better, your trigger wheel is probably retarded. (try one at a time)

That ignition map isn't going to get you in trouble, even if you go a bit lean. Ours is much more aggressive than that and we've (accidentally) run at 15:1 AFR for a whole endurance :O

Pradeep

04-14-2010, 10:48 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Rich misfires will indicate as very lean on an oxygen sensor. Remember, the sensor is measuring the oxygen content of the exhaust gas, not the fuel content. In other words, if you've got so much fuel that you can't get the mixture to ignite, it will actually show lean because none of the oxygen is being used for combustion. In my experience, if this is your problem, your eyes will also be burning from all the fuel going out the tailpipe </div></BLOCKQUOTE>

My eyes were burning, so it must be a rich misfire.I've ordered a a new lambda sensor, so I'll be able to verify as soon as it arrives.
I'm targeting AFR close to 14 up to 4000-5000 rpm and then 13.2 at higher RPM.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Try advancing all your timing by about 15 degrees and lean your map out to peak at about 2.6-2.8ms pulsewidths (@ 52 psi) and see where that gets you. If it runs better, your trigger wheel is probably retarded. (try one at a time) </div></BLOCKQUOTE>

I tried this. Advance at 1000-2000 rpm at 40 deg gradually increasing up to 50 deg (max allowed by PE) at 5000 rpm. The engine was running much better but did not get past 7000 rpm and again there was back fire in the exhaust as the fuel map was the same.
When I lean out the entire fuel map , the engine does not start.
I'll be checking my trigger wheel tomorrow.
I spoke to Brian at PE and he told me that the max advance I need will be 45 deg and that I should be concentrating on the fuel map.
As I cant advance beyond 50 deg now, I'll try to lean out my fuel map and see what happens.

Thanks for all the inputs.

Kirk Feldkamp

04-14-2010, 01:43 PM

Bingo! Eyes burning is usually past the point where the O2 sensor can read properly (in my experience). Time to remove fuel!

Don't lean out the entire map if there are sections that work well already. Just focus on the areas that are way too rich for now (above 7000 in your case). I've worked with people that get trigger happy with full table adjustments, and it usually causes more confusion than good.

-Kirk

Wesley

04-14-2010, 05:58 PM

Yeah, your shape actually doesn't look that bad if your intake design is anything close to the common design, just the magnitude of the cells from about 50% throttle and 6,000RPM up to 100% throttle and 10,000RPM.

Don't forget part-throttle tuning! It's just as important (if not moreso!) than full throttle tuning. In an auto-x course full throttle is pretty rare (at least from our drivers.)

DcooL

04-15-2010, 06:59 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> However we still haven't been able to get our engine past 7500 rpm.
I think it might be because the ignition timing we are running is too far advanced but when I retard I get a lot of back fire in the exhaust.
There is also have backfire in our intake manifold from time to time and our MAP sensor is malfunctioning currently. </div></BLOCKQUOTE>

The timing can be verified very easily with a timing light on cylinder 1's coil. Find out what your actual timing is based on; say a 30 degree advance on the PE. Always have that offset (there will be an offset if you use the stock wheel) at the back of your mind. We ran last year with the ignition map flat at 50 degrees of timing and 30 degrees of 'real' timing, and had no issues. (The engine, however, would run out of 'usable' advance at about 11000 rpm, would backfire there and was a pain in the noise test). When I started this year, I used that as my starting point. Still works fine.

Once you are confident of your ignition setup, go back to your fuel table, and change fuel values only, hopefully with a multiplier like 1.05. That should allow for finer control, and should yield positive results.

Post back here if you have any news.

Pradeep

04-22-2010, 01:53 PM

Im still waiting for the new lambda sensor to arrive, so cant really do much worthwhile tuning till then.

I was checking the spark plugs today and noticed oil on the thread of cyl #2 spark plug ( again ). When I took out other plugs, there was'nt any visible oil but they smelled of burnt oil.

Is it normal to have some amount of oil on the spark plug ? Can it be a problem with piston rings or a oil leakage in the cylinder head ?

Last week the ground electrode of spark plug in cyl #2 got distorted (see picture). You can see the oil on the threads. I am concerned as to how it happened and whether the oil on the plug and this is somehow related.

http://i44.tinypic.com/2d48ia.jpg

If the piston ring is indeed the cause for the oil leak , could that also be a reason why the engine is not going above 7000 rpm. I can see a stream of gas coming out of the PCV when the engine is running , this again points to the conclusion that there is a problem with the piston ring(s).

I wanted to know if Im on the right path with the diagnosis or after so much time of trying Im hoping for one cause for our many engine problems.

Pradeep

04-28-2010, 12:58 AM

Im still waiting for the lambda sensor to arrive.
A new set of problems have started with the engine this week.

1. Oil on spark plugs: While changing the spark plug I noticed a layer of oil on the thread of the spark plug. Plug in cyl #2 had much more oil than others.

2. I've noticed is a stream of gas escaping form the blow-by (PCV). This is happening more during initial cranking.

3. Very rough idle :When the engine starts it idles badly for sometime (like 30 secs ) as if only 2-3 cylinders are firing then suddenly its starts running well.

4. Erratic starting : Since the last 2 days, the engine does not start in one go , after cranking many times (atleast 7-8 times) it starts. After which again it refuses to start (even when starter motor is taking it to 450 rpm).

All these problems make me think that there might be a problem with the piston ring wear. The engine starting problem could be because of insufficient compression and the oil on the spark plugs could also be due to the same reason.

Is my diagnosis correct ?
What other symptoms do I have to look for, to be certain that this is the problem ?

Thanks

PatClarke

04-28-2010, 03:26 AM

Pradeep,
build yourself one of these. One of the best engine tools to have.

http://www.vmaxoutlaw.com/tech/leakdown_tester.htm

Pat

Pradeep

04-29-2010, 07:05 AM

Mr. Pat Clarke, thanks for the link.
We have managed to find the compressor and pressure gauges in our college lab. The spark plugs have also been removed and tapped. Only thing remaining are some fittings which should be done by tomorrow. If everything goes to plan, we'll be able to complete the test tomorrow itself.

Thanks again

Pradeep

05-01-2010, 02:21 PM

We did the test at 75psi pressure and there were no leaks.

After that we tried starting the engine, it did start and ran for about 5 mins.But when we shut if off and tried starting again, it did not start.

If cylinder leakage is not the problem, then what else could it be ?

Mikey Antonakakis

05-01-2010, 03:34 PM

Your tune maybe? Warmup enrichment, cranking values, etc. These engines are tricky to get to start when tuning from scratch. I've found that bumping up timing in the idle portion of the map can help. Make sure your plugs are fresh. This will throw you off more than anything, at least in my experience, when you're writing a new fuel map. If they are black and oily/greasy clean or replace them.

EDIT
I just looked at the ignition map you posted, you should be able to idle just fine with that timing once you sort out fueling. If you can't get it to start and idle nicely with fresh plugs, regardless of fueling, check your timing. We've been tuning and even though I thought I set up the trigger wheel properly, we still had a significant offset when I checked with a timing light.