This is something I've wanted to post forever and just never spent the time typing it up. Now that it's after 5 I can "play" a little. I'd be heading home, but it's monsooning here. ABSOLUTELY ANY tune that's safe on the street should be easily "beaten" by a tuner on a dyno. To clarify; ANY tune that runs safely on the street is normally EASILY tweaked to make more on a "magic pass" on the dyno. With the hood up, intercooler cool or even wet, a big fan directly on the engine, and a load of 4th gear or less, a tuner darn well BETTER be able to make more power than what’s safe with the hood down, engine bay heat-soaked, fully-loaded with questionable gas, and uphill in 6th gear. I’ve tuned on a LOT of different dynos. From essentially zero inertia Dynapacks (you have to remove the wheels and there is less inertia than having the wheels on) to HEAVY 4,000 pound Dynojet rollers to 2,000 pound, loadable Land and Sea’s to our low-inertia Dyno Dynamics at Forged. They ALL are not the same loading as the street. With the DD you can easily change the load to mostly “encompass” the loads seen on the street, but it’s still not the same. This doesn’t matter all that much with NA cars, but with turbo cars they can run SIGNIFICANTLY different on the street than they did on the dyno. Almost all cars make more boost and run leaner on the street than they did on the dyno. Some dynos (such as Dynojet) do not have adjustable load. Your only option for load is what gear you run it in. Generally you run a car in the highest gear that keeps the top speed reasonable. When you take a car off the dyno and go to the street it RUNS DIFFERENTLY. I have often been asked “are you going to put it back on the dyno after the street?” I often reply with “would you like it to run correctly on the street or on the dyno?” Obviously, it would be interesting to know what it would make on the dyno once road-tuning is done, but for the most part, it doesn’t matter. If we take a car straight off the dyno to the street it will usually make at LEAST a pound more boost (in a high gear) and run up to a full point leaner. So if it made 20 psi and was 11.00 afr on the dyno and made 300whp, when you put it on the street it might make 21psi, run near 12.0 afr and make MORE than 300whp, until it blows up. To make it safe you have to add fuel and turn down the boost CONTROL (not the actual boost run). If you were to take that car that now makes 20 psi and 11.00 afr on the street, and put it back on the dyno, it would (in theory) make 19psi and run 10.00 afr and probably make 275whp. ANY tuner should be able to turn it back up to 20 psi, 11.00 afr and 300whp. WOW, your old tuner must be a hack and your new tuner is clearly an amazing genius “So why use a dyno at all?” you might ask. Tuner's generally like to start tuning on the dyno. It's a nice controlled situation where you don't have to worry about other cars, cops, getting stuck on the side of the road, etc. It's much faster to "rough" in a tune on the dyno than on the street because you don't even have to look out the windshield. The best description for what tuner’s do is “putting numbers in boxes.” ASSUMING everything is mechanically right and “normal” (LOLOLOL) all tuners really do is “calibrate” – tweak the input until you get the right output. Most tuners know approximately what "data output" we expect each car to comfortably run; as in how much boost, timing and what AFR we think that setup should safely be able to run. The initial tuning is just tweaking the input to get the right output. You have to iterate (tweak, test, analyze, tweak again, test again, repeat) to find how much wastegate duty is required to make the boost you want, where exactly that puts you on the load maps to find what timing and afr to have where, etc. Within reason, more boost, leaner afr, and more timing make more power. Certainly the dyno can show you when running a little richer lets you run more timing and whether that makes more power than leaner and less timing, and finding the right cam timing can really only be done on a dyno. So, most professional tuners can also tell you about how much power the car will make once we've got a "typical" data output. That typical data generally has some safety margin in it to deal with reality. In reality you have to be ready for bad gas (or at least not great gas), hot engine bays, high-loads, mis-alignments of the moons etc. Once we've got it running the timing, boost and AFR that we like, then we can “push” and see what the car will actually be happy with. We can see if it'll gain power with a little more boost, more timing, leaner, etc. Sometimes the moons align and a car will stay safe and happy a bit beyond what we expect. Sometimes the car’s not “quite right” and it makes less. It could have bad gas, one light injector, crusty plugs, a curse, etc. Then most tuners make a "magic pass." They get a little more aggressive with the tune, hose down the intercooler(s), let the engine bay cool, etc etc. I usually tell my customers when I'm making what I consider a magic pass. I let them know that the car probably won't be happy with those settings on the street. Particularly if it's hot or they're wanting to be able to redline 6th gear... If we take a car straight off the dyno to the street it will usually make at LEAST a pound more boost (in a high gear) and run up to a full point leaner. Subaru's that have been taking 8 seconds to go from 2k to 7k rpm on the dyno and moving 3.2 grams of air might do the same rpm in 6 seconds but move 3.5 grams of air. Basically THE DYNO IS NOT THE REAL WORLD! That's why I always tell people that it's not how it runs on the dyno that counts, it's how it runs on the street. So, again, you take a car off the dyno, you turn down the boost 3 or 4% wastegate duty, you add a few percent fuel and you start road tuning. Most cars require a slightly different shape wastegate curve and sometimes a SIGNIFICANT amount more fuel. Generally we get the car back to running what we think is safe and reliable and that's what the customer gets to take home. That’s usually about the same “data output” as we told them was what it would make in the real world. If you take that setup to another dyno, or even if you put it back on the same dyno. It will run that pound less boost, and up to a full point richer than it was on the street… More later, gotta take the break in the weather.
I have definitely seen changes between the street and the dynos I have worked on. Most of the time I see 1-2 psi variance between the street and the dyno. I have not seen air fuel quite that severe, but there will be a change. I have typically seen around half an air fuel point leaner on the street. I know Ben's car in particular had 2 psi less on the dyno with a MANUAL boost controller. This surprised me a little since it was on a Halman Pro manual boost controller. On the street it was hitting 26 psi and with the halman in the EXACT same position on the dyno it was at right around 24 psi. It also hit much higher MAF voltage values on the street than it did on the dyno. On the dyno it never got over 4.68 volts where as the street it was approaching 5.00 volts. Had I just tuned it on the dyno, it would likely have never hit those cells and they may have never gotten dialed in 100%.
Possibly to find a ceiling to know what the potential is before starting the street tune? Thanks for the right up Scott. We used to have a lot more of this kind of info being posted on here. Its a shame that it happens so rarely now...
I used to post stuff like this on here all the time, it was usually well received... lately, it hasn't been worth it though. Maybe we've turned a corner Siegel
why don't you just come out and say it belvn. stop tip toeing around it. edit: fuck it. why do I always have to be the asshole voice of reason. bullshit like this isn't well received because it's a thinly veiled attempt at some kind of internet pissing match between forged and topspeed. I, for one, could give a shit about those two shops going at it. shit threads like this are some kind of stupid attempt by scott siegel to act the innocent part. NOBODY CARES. there was nothing informative in there at all. it was just some stupid fluff piece to defend whatever kind of stupid fucking argument they are having on this particular day. yes, we get it. it's the elephant in the room. you tuned a car, the guy went to topspeed, and now you feel the need to 'defend' your internet tuning honor by writing this ivory tower tuning piece. get the fuck over yourself. so can we skip all the hand wringing and dick waving and just really call it like we see it?
Actually I wrote it because most people don't realize that when a car comes off the dyno and goes to the street it runs differently. With the SAME map it makes more boost and runs leaner. Once you set it back to the same boost and afr on the street, if you put it back on the dyno it's low on boost and rich. Integroid, I meant to ask you, I saw your car on a trailer heading across the top of 285 heading West. It was Wednesday July 11th. How's it going? Siegel
Nope...I have had a rough year personally with deaths in the family and injuries. Going to the strip was not one of the priorities. Maybe once it cools off I will go.
Nicad, For not caring, you sure do spend a lot of time commenting... and if "nobody cares" there sure are a lot of nobody's in here right now (including you, if you really don't care, why don't you go do something you do care about???) Hey guys :wavey: I'm trying to save a 400+ component drawing to a remote server and it takes 10 minutes :/ Siegel
for a moment it was nice to read something that wasn't someone tearing apart someone else. i definitely sensed a little bit of "defending" in his write up even before i read your comment nicad, but i'm pretty sure taking it to that next level wasn't really necessary for the small hidden agenda in his article. edit: i saw the original post and understand where you are coming from, so changed my opinion in my later posts
what a stupid argument and you know it. straw man much? I'll wait while you google that. I can not give a shit but still comment on the rampant stupidity as I see it. get it? or maybe I should draw a pictshur for you. Hey guys :wavey: I'm making the internet work
The funny part about all of this? We, as forum members, can read the shit storm and post our opinions. They're simply that...opinions. They in no way affect our financial situation and will have no future impact on our business. If you want to look like an internet badass, go ahead...we get entertainment out of it. Oh, and grow a pair, stop beating around the bush (SS), you know why the car was on the trailor, either say it or gtfo
I've heard rumors, and been told things by people that asked me not to say. I don't post rumors, and I don't betray deserved confidences, but I saw the car on the trailer with my own two eyes, so that I can bring up. Everybody loves requesting full disclosure on here, when it suits them, but here's a high profile (on this board) car that was on a trailer when it should have been running great. But of course all the internet bullies are currently swinging on the shop who had this car last, so nobody wants to talk about it... Siegel
listening to this isn't even that entertaining, it's obnoxious. call me numb, but my first experience with tuners/speed shops w/e involved a guy that would call someone a douche bag to his face if he deserved it. someone that makes comments like (and yes i did just go to his forum to lift this quote) that's entertainment
Whatever. I haven't had a warm and fuzzy relationship with Siegel, he has never tuned my car, I don't really know him outside of doing a track day at little tally. I didn't even see that this was cross posted in another thread until after I read it. Way to jump to conclusions. As for the dick waving statement, I couldn't agree more and find it odd that the people involved are thanking you for your post...
honestly, here's another good one. maybe the elephant in the room should involve more shit like this until then. can we please think of something better than "he said this", "oh yea well he said this"...."oh yea well he said this"...
Dynos are not the real world In Nicads defense (not like he needs it) it's because he has the balls to say it like it is. You think everyone likes you...think again. You constantly talk trash about other people. Sometimes you need to step back and look at yourself. Some people just want to see you fail at what you enjoyed since you blatantly tried to do to another. Funny as the other came back bigger and stronger than other. That's all I have to say.....so that said