Thread: VE-T blogger, dynos, movies, and pics.

It's easy to avoid detonation on the street, then go to the dyno and detonate. Intake temps at the dyno aren't even close to the real world.

hmmmmmmmm..............how long and how many cars have you tuned, in what kind of building, with what kind of airflow, with what kind of dyno?????? Than talk to me........

Its easy to avoid detonation on the street........please answer my qestion of how you are listening to this detonation?????? ON THE STREET.....
K yep your intake temps are the primary cause of detonation......riiiiiiiiiiiiiiiiiiiight
Lets just forget about the whole boost, timing, a/f and such. I certainly understand the importance of intake temps, but you will never be able to properly tune a car to zero detonation on the streets......somewhat pending on the car and what your tuning with mind you, but in most cases....never. Especially with a JWT chip, I have heard plenty of those detonate with 20lbs thrown at them.
Okay you have no detonation on the streets, and this is easy as you said, but super easy on the dyno than....Who tunes your car?????

Answer my first questions and we shall go from there......

First off, you guys must understand that my elevation means that the actual oxygen content up here on 20psi is about the same as the oxygen content at sea level at 17psi. There is no doubt that 20psi at sea level would start knocking sooner or later. But the air up here is thin, about 13.0 psi compared to 14.7psi at sea level. Not only that, but oxygen content up here is less also. Hope that didn't confuse anyone.

I have read the plugs and listened to the motor and I don't hear any detonation. That doesn't mean it is not detonating, but I doubt it. I hit 25psi once in first gear, that was where I started to hear some crackling noises.

How is the dyno going to make the car detonate more? the car isn't even loaded as much on the dyno as it is on the street. I understand air flow issues and IAT values when stopped. But my iat sensor is about 8" from the turbo inlet and I have read some very high numbers here. Upwards of 215*! Is that insane? yes! I need a cold air intake and some kind of hood ventilation!

Even still, the plugs looks good and I don't hear any funny noises. I am going to check the plugs again though just to make sure.

my friend has a yamaha 600r. We played around on the freeway yesterday and I must say the car did very well. I kept even with him with a passenger in my car. A 280lb passenger. The same guy who does the filming for my videos haha.

The car does well.

Here are pics of the plugs after a good run. There is a slight yellowish tinge on the ground electrode, I don't see and "danglers" like I have seen on some cars. Let me know what you guys think. Sorry the pics suck but I have a crappy camera.

I was just expressing my concern aloud, not to your posts coheed but the other gentleman.
On our dynodynamics we can load the car pretty heavily to simulate street driving, still not as loaded as actual street driving but way better than a dynojet. Your elevation does make a difference though for sure, 215* is not insane either and the plugs don't look bad but hard to see cause of the pics....
My other question Coheed is how are you listening to your engine....I just want to know, not saying anything is wrong. But there are specific ways to listen that only a dyno will allow that are far more accurate than the street.

I pulled next to a wall and listened to the engine as I hit boost. When I hit high boost (25)psi I could hear a crackling noise like someone wrinkling plastic wrap or something. Kind of like static. It did that for just a sec and I backed off. After that, i drilled out my restrictor for the boost controller to prevent spiking again. Then I took it out again. The car still spikes at 21psi and falls back down to 20. I wonder if my camera would be able to detect detonation? maybe I can put the camera in the engine bay and strap it to something while it records. It picks up piston slap really well, maybe it can pick up the detonation? I can post the video if you would like.

The plugs look good, there are some really really small specks on the plugs on the porcelain, but they look normal really. I have seen plugs that show detonation and these do not look like those. the small spots are hardly noticeable unless you look really hard. I am going to retime the car before I take it out and maybe set the timing back to 15*.

The camera looks to be fine. You need to get familiar with the macro focus button though. =]

I must admit I have no idea how to use a camera. I pulled the codes on the nissan datascan. I found tons including coolant temp sensor, tps, and rear o2 sensor. Those I expected, I have had them unplugged a few times for diagnostic purposes. I also got code 34 "Knock sensor circuit malfunction". I don't know what this means exactly. Was it detonating? is there a problem with the sensor or wiring? So I backed timing back to 15* base. Here is the video of the timing marks and where the dizzy sits. The bolt is not in the middle like some I have seen, but the block and head have been resurfaced so I know that the timing is right.

Let me load this video and I will post it.

Coheed, I hate to do this to your thread, but excuse me while I defend my e-manhood here for a second. =/
There will be good info about inlet air temps if you read to the end.

Well, I'm not exactly sure how long the cars were that I tuned, but I've tuned four of them.

I've tuned countless hours on the street, in a typical garage complex with multiple bays with floor mounted Mustang dyno, in a warehouse building with excellent ventilation and surface mounted Dyno Dynamics machine.
The garage complex had open doors on the front and rear of the car with typical high flow fans aimed at the front of the car. The warehouse place had a dedicated exhaust fan in the ceiling along with and open bay door with typical large fans pointed at the front of the car. The street had terrific air flow, probably the best you can wish for.

I'm not really sure if you're calling me out as a novice, or if your grasp of the English language is poor. I'm guessing both?

I've used knock sensors along with Coheed's wall technique (works amazingly) as well as just listening. One could also employ the coffee can technique, or a more sophisticated electronic version of that same technique if one wished while on the street.


Yep.


I never said they were. They are, however, the big difference between driving on the street and pulling on the dyno. You can knock on the dyno, and then drive home with none. Or, let me put it another way. You can tune knock out on the dyno and then have an even larger margin of safety by driving on the street.

I don't know how to refute this. For one, it's just stupid to say. You don't think I could tune a car to avoid detonation by just street tuning? Are you serious? Also, I've done this before, as have countless other tuners. Dynos are nice, but there's nothing magical about them that removes detonation from engine operation.

Really, this is your problem here. If you'd just said it was hard to do, we'd be friends, but you've gone and said "never". I find it funny how you qualify the statement by saying "in most cases" but then go on to say "never". C'mon man, no one's buying this.



A JWT ECU is a non-tunable ECU. Of course you can't avoid detonation with it. Street vs. Dyno means nothing here.

I believe it. Ever heard Coheed's car? This is my point. Just because you cater to complete idiots (90% of dyno customers are idiots) who think they aren't detonating on the street when they are doesn't mean Coheed can't tell when his car is and isn't detonating on the street. It also doesn't mean that just because your customers' cars detonate on the dyno that they were lying or don't know what they're talking about when they say they weren't detonating on the street. The dyno is a much more stressful place for an engine than the street due to limited air flow, and can be made worse by loaded dynos (Mustang and Dyno Dynamics). Like you said, the Dyno Dynamics can put a lot of load on the car, but you failed to mention that it typically puts more load on the engine than the street. They are designed to allow the engine to accelerate at a set rate, no matter what. This means the more power a car has the more load it will place on the engine. The net effect on the street would be like doubling or tripling the mass or your car. Sorry, I'm getting way to deep into this. Let me continue.

I tune my car. Why do you ask?

Done.


It depends on how fast you're allowing the dyno/engine to accelerate. You can make it less load, the same load, or more load than the street. From what I've seen, the typical thing to do is allow for a rate of change of 200-300 rpm per second. This has the result of loading a car with more than about 300 WHP with more load than it would see on the street.


215°F intake air temp is INSANE. When intake air temps are more than 60°F above ambient you've got major problems with compressor inefficiency, insufficient intercooler performance, etc. Pump gas can't deal with this sort of situation. Detonation will be the name of the game here. Coheed, you've got to do something about this. Is this typical of the SR20 crowd?

Name me one thing you can do to listen for detonation that you can do on a dyno but not on the street.