I currently have a G35 (VQ35DE) that was tuned in Tempe, AZ at UMS tuning. I am running a Greddy Emanage. I currently live in Las Vegas but spend time in SLC UT frequently. I would like to adjust the tune on the emanage myself but don't have access to a dyno. I know there are a lot of competant tuners that also do road tuning.

Does anybody have experience and tips on road tuning to get a tune dialed in even better?

Have one person drive while the other monitors and sets. I have done both at the same time, but it's dangerous and takes longer. I stick it in third gear at a low RPM so the engine sweeps up slowly and smoothly. It makes it easier to dial things in quick than trying to tune a motor winding up quickly.

I have done that. A/F is easy to adjust - but how do you know how much timing you can throw at it?

Also, how do you know/adjust the load column for the tune?

Thanks.

tollboothwilley wrote:I have done that. A/F is easy to adjust - but how do you know how much timing you can throw at it?

Also, how do you know/adjust the load column for the tune?

Thanks.

Well you can buy a in cabin knock sensor, and up the timing in small increments until it starts to ping then back it off. Also why do you do the pulls in 3rd gear? 4th gear is better but you are going to need a lot of road.

i've done pulls in both.

I guess with a visible knock sensor you just do 250-500 rpm increments at a time and see if it knocks? increase til it does then back off 2* or so?

adding timing based on knock isn't the best way to tune. Tuning for fuel on the street is fine, and can be done safely with 2 ppl in the car. But I REALLY suggest doing the ignition tuning on the dyno. More timing doesn't always mean more power. Increasing the timing till it knocks and then pulling it back often yields more timing than is what is needed. If you're near the knock limit of the fuel, this can be used to tune for the max power of the fuel available, but I would argue that if you're knocking before making max power with timing, you need to look at some sort of increase in charge cooling (intercooler or water injection), increasing the octane of your fuel, or decreasing boost/compression.

I've street tuned for ignition timing, and it was a pain in the butt. Make sure the desired AFR, suspension, and tires are in check before starting.There are two ways that I've have done it.

The first way I have done it was with "electronic Det Cans" made from a stereo wide frequency computer studio microphone. You want a microphone that is of quality and able to pick up high frequency sounds. The microphone was taken apart and epoxied to a super sturdy mini welding ground clamp. The sensor is insulated with canned foam spray to prevent outside noises from feeding back into the mic. This lets the mic pick up sound that is feed through the metal clamp itself more. Place the clamp on the block near or on the oem knock sensor bolt. The other end of the wire is left alone with it's 3.5mm jack intact and plugged directly into my laptop. On the laptop, unmute the microphone settings with windows media player setup to show the realtime EQ spectrum as a visual (can be recorded to view later too). I also wear a pair of bose studio headphones plugged into the laptop. Now I can hear any odd clicks and pops the engine makes that stands out from engine noise. The visual EQ will have odd spikes and peaks on the high frequency side of the scale when something begins to happen. Usually with the headphones, you can't hear it (we're only human and programmed with a certain range of frequencies that we can hear) until the knock really starts happening. The visual EQ will usually register pings before you can hear the funny clicky rattle canned BB or wobbling poster board sounds, so I usually use the visual as a tuning tool, and the headphones are for letting me know to let off the throttle when I am not looking at the screen. ***EDIT: I forgot to add that with this method, you can press the brakes while trying to accel to simulate a load holding dyno. This helps keep full load or targeted part load at a certain RPM longer to induce heat etc to see if she pings. Careful not to do it too long or your brakes will fade and warp. It is great for 5th gear low rpm, but it can also easily show the limits of your brakes in lower gears at high RPM and speeds.****

The second way I have gone about tuning was with a G-sensor performance meter such as G-Tech and the like with RPM pickup support. Android handsets and Iphones have dyno type apps that work decent for this too, but you will have to do the math for gear ratio vs speed vs rpm. You want the RPM relation to be able to tune with a graph. The main thing we are looking for here is a detailed graph of the torque line. This method will only work well with a nice smooth stretch of road that you will be making pulls on. All pulls will have to be in the same direction and same spot of the road to help prevent adding more variables to the mix (draws attention, so keep it in a secluded spot). What you do is record either 3rd or 4th gear pulls and have the meter record the run. Once the initial run has been made, all following runs have to be in the same gear. Now pull the first run's graph up and make sure it is ok to read without any odd jagged spots from bumps etc. Now add timing (1 or 2 degrees) for the spots of interest in the RPM band and make another run. Now compare to the first graph to see exactly how much torque was gained in the area that was changed. If the change was a fairly large number, then it is safe to add some more timing or keep it and carry on. You keep doing this until you get minimal or even no gains in some cases. Audible knocking and engine damage usually occur way after the MBT point. No gains means you have reached maximum brake torque(MBT) for your engine with that particular fuel and total compression etc. I usually do not go as far as to hit MBT unless on a dyno, but I do get to around only 1-2ft/lbs gained per degree of ignition advance added. Once I get to that minimal gain spot, I pull the timing back 2-3 degrees to be safe due to fuel quality changes etc. I also usually do multiple recorded runs to help any deviations that can be found in a single recorded run. This keeps the graphs more consistent after I take the averages before making a change to the timing. The G sensor meter, phone, or whatever it is that you use will need to not only be consistent, but very stable during acceleration. Don't hesitate to tape it down somewhere if needed.

I use a combination of both of these methods now when tuning a friend's or customer's car. I'll use the microphone jig without G sensor when someone just wants a safe tune with decent power. Throwing a Gtech into their car along with microphone jig is done for the guys who want close to full potential. Dyno tuning is still far easier, but as I've seen all too often, they just aren't available everywhere.

Disclaimer: Road tuning can get dangerous really fast. You have no control over other people, animals, or the weather. No matter what methods you use, road tune at your own risk.

VERY NICE POST!