If any of you have followed any of my build threads here is what ive done
HO Cams
HO Valve Springs
Extrude Honed HO Mani
HO TB
P&P 2.4 Head
1 MM Oversize Valves
LC1 Wideband
Going to be installing the M45 310 CC injectors before starting to tune also
Going to finally get to tuning this thing this week and was looking for some suggestions of what to hit to get the most from the build
Still quite new to HPT especially with the Fuel and Spark tables, i know my way around the program quite well though
Was going to start with Shifted VE Tune
Any help is greatly appreciated
What AFR are you going to shoot for?
FU Tuning
dyno
EGT and AFR readouts. best way to tune.
Figure an AFR of 13 to 13.5 should do
Don't have any dyno access within 4 hours of me PJ
Any helpful hints would be greatly appreciated
I would not go that lean with a LD9. I tried 13.0-13.2, but it seemed to like 12.7-12.9 better.
FU Tuning
Whether the car is N/A or has forced induction, you approach the tuning process in the exact same way, using the exact same tools.
Why did you pick a 13 - 13.5 afr? Was that number recommended to you? Did somebody give you MORE bad advice?
Tuning is tuning... you need to understand a lot of things before you even begin to change those #'s... like what the timing means. Why a cam would require you to fire the spark plug earlier or later, etc etc.
Also bear in mind that phantom knock you had 2 years ago, be sure that it has been dealt with or you'll be chasing some ghosts.
I recommend you read a few books before you try to tune the engine, especially since you've made some drastic changes. There are a few available in PDF format on the web for "previewing" that will at least give you a ton of good advice.
As much as some people around you think they know how to tune a car, unless it's been done with an EGT probe and a dyno they're just pulling wool over your eyes.
First get your constant right, then work on off-throttle and low-speed drivability with the VE tables and watch the timing. You will have to adjust the timing accordingly at idle and in those same off-throttle and low speed cells. The engine is going to tell you what AFR it wants, not anybody else. The engine is going to tell you what timing it wants via EGT's... not anybody else.
Once the car is driving well at low speeds and general normal driving, you begin to work on WOT tuning. Because you cannot do this on the highways Darren, this has to be done on a dyno. You can't take 3rd up to redline on a public road and call it safe, and you will need to do this over-and over-and over again. That, or you'll have to hit up a track.
Nail your AFR's down to what the engine wants, then work on the timing, then re-check your VE's because timing will affect it and adjust as such. The car will respond differently in different gears so what works in 3rd might not work so well in 4th due to load. Bear that in mind.
As I said, do some heavy heavy reading before you attempt this and don't take somebody elses advice on it. It's you that paid for this project, it's you that has to deal with it if something gets f'd up, and its you tuning the car and changing the #'s. There is a lot you can wrap your mind around before you go out and tune the car, and it'll be frustrating if you don't quite know what you're changing and why. You've made QUITE a few changes to the stock motor so I wouldn't expect the stock tune to be anywhere near in the ballpark.
If you are doing this without an EGT probe, you won't be doing this properly.
Good luck.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Ghost knock shouldnt be an issue anymore as this is being done on a different 5 spd car
EGT probe i don't have any access to at this moment
I would love to get on a dyno and get this all tuned properly and that will be done but for now i have to get some kind of tuning accomplished
Can you recommend a good online read Chris?
It's not really as hard as people make it seem. You see alot of JCO builds and stuff that take 17 years to complete, and then they just blow up. haha. Happens all the time.
Shoot for 12.0 : 1 for initial tune. Keep leaning her out till you get knock. then add a tad back in, but not too much.
Put in the gas you plan on using, say 91 octane, add timing accross the map till it knocks, then back it up a bit. More overlap means you can run more timing.
It's not that big a deal really, the cam is still very "small" from a performance standpoint, lol, nothing too crazy happenening there at all, it came on a factory vehicle, by no means is it a "race only" cam.
I use both pedals to test all load ranges on the higwhay, so, basically put in in third, and use the brake to control load, (this doesn't really work soo good now, cause my car's engine can't be held back by brakes, it would just melt them off) but it would likely work on a motor car 2.4L. Just try 3000 rpm at whatver @ 60 - 70 - 80 - 90 -100 KPA (laod), then again at 3500 RPM, ect all the way to the top do this for a few mins at each RPM then go back home and look at the logs, and go from there, it wouldn't take long at all to do.
This is the way I did it, it was pretty cheap, and the tune was all done by myself, which is nice, cause you aren't paying people to use their dyno, ect, if you make changes you can do your own thing to get it back into tune. I can't justify booking dyno time everytime I make a change, lol, I would be on the dyno 4 times a season. Instead I go through a set of brakes pre year, which on a J-body is almost free.
When you decide to add more flow, for example, I added headers and full 3" mandrel bent, all i did was add 20% accross the map for fuel, then went out and datalogged it. found it waas actually really close, I ended up removing a bit more gas down low and the top - mid was about right it was tuned in an afternoon, for the price of 2mm of brake pad wear.
no dyno req'd.
Another HUGE driveability thing for my car was the Accel Enrich (pump shot) It doesn't seem to be affected by VE values at all, so it was basically WAy to much pump shot, I'd give it some gas AFR would drop to 9.0 :1 for 2 secs then back into the 13.3 range. Start over-rich and lean it out.
When tunning you should NEVER have a lean spot. always start WAY WAY rich (you may foul plugs and clog cats but cheaper than replacing slugs) then lean it out as you go. You'll see it will clean itself up real nice. My car was "driveable" in about 1 hour of messing around (injectors were 130% larger than stock)
Here is a good ittle read on why EGT's are NOT the greatest thing out there... I wouldn't get one if I was you. You're not building a spaceship here, lol, it's a cavalier with some factory HO parts. Should be pretty easy to dial in...
http://sdsefi.com/techegt.htm
11.92 @ 122.69 MPH Rotrex Blower / Intercooled / Water-Meth / 100% Daily Driver / 381 WHP
