Dyno results in!!

[crunchymilk55]

Sorry I haven't posted this earlier, but I haven't had time to do it properly. I've been really busy, and just got back in town a while ago.

Ok, here we go. Me and a few friends leave in 2 cars. My car and a DSM wiseman friend's car, (his car is suck, T67 turbo, enough said). Among my buddies that went were the owners of a 400hp supercharged 350z and a 381whp SRT-4 owner. We meet up at the dyno with another friend's car, a nicely built 99 GST. (details on this car later, see the other thread (deal of a dsm)

So I volunteer to go first, anxious to finally get on the dyno. We strap her down and let her rip. Uh-oh, the dyno is losing rpm signal around 3500rpms. But hey, according to the dyno I'm making something around 210hp around there, looks promising. So, the dyno guy (friend of a friend) switches the signal (soime laser thing to the crankshaft) I have no friggin clue, but whatever. So we dyno at aroud 16 psi all the way to redline. Decent power, but a/f is too rich, but it is almost a straight line on the wideband. It was a good street tune, a bit richer than I wanted, but it worked. here are some pics of my baby on the dyno:









So we take away 5% of fuel via dsmlink. 11.5's across the board, perfect. This run made around 230/270

This whole time I've been experiencing some minor boost spike, it's definitely seeable on the dyno sheet I'm getting ready to show. Anyway, we turn up the boost so it spikes around 23 and settles around 18-19. I don't want the spike to run that high, I have the fuel for it, but don't have the headgasket. So this run we pull around 250/290. We mess with the timing a bit, but the car is knocking too much. 86 degree weather and 100% humidity (it was drizzling outside) is killing the tuning possibilities. We do a few runs messing with timing, and eventually I decide to go conservative (this car has to last me all of college and med school folks) so we're running around -3 timing across the board. The results are shown: 250.44whp and 295.06wtorque
here's the dyno sheet: I don't have a scanner, this is the best I can do



so...the big question? Am i dissapointed? Yes and No. yes, because this is definitely not the power I expected, I was definitely humbled. No, because I now know exactly what I need to do. I need cams and I need to fix this boost spike. These won't be problems soon enough, so I can deal with this. Look at the dyno, I hit max power at 4k (prob less with actual load on engine.) With cams, the power level will continue to the rise. The stock cams just can't breathe up top, I will have HKS 272's in sooner than expected. With cams, 300hp and 300tq should be rather easy. But there's a good side, every single dyno run, dsmlink shows at least 36lbs of airflow up top, a few even hit 37lbs. With cams, 40lbs a minute should be easy and I'll be making very good power. I will attach a dsmlink log (Kevin, Id really appreciate it if you gave me your thoughts here, especially the timing vs. knock)

Log if you have dsmlink, here's my post on the link forums

http://www.dsmlink.com/forums/showthread.php?t=7989

That's all for my car, I wasn't too happy, but I can live with it. More tuning, cams, and a fix for boost issues are on the table, they will get done soon enough, then I'll head back.


The next car was a 60-1 powered GST with full bolt ons, dsmlink, and cams





This car had some major problems, mainly the electronic boost controller settings, and other issues. We had to make a trip to the nearest parts store for new plugs, his old ones were shot. Long story short he made 371whp or something like that. Odd thing was dsmlink never showed a single hint of knock at any time during all 22 pulls. I mentioned this, but supposedly when a knock sensor goes out it reads a steady voltage. Anyway, he made over 25 pulls to get everything working, but finally did, and had a strong car. This was a bad mofo, even though he still has some issues, his turbo and car should have made at least 425 IMO. Problem is, he wont get another shot for a long time (read the other thread I just posted)

[ez1286]

Thats pretty good, probably about what i'm putting down (well maybe less b/c awd, but we have similar mods). Did you do the tuning yourself?

[kjewer1]

I'm really curious to see what you guys did with timing. I almost never agree with going below stock 2g timing values if you are over 2.1 g/rev, I have to wonder if there isn't something else causing the knock. I wouldn't worry too much about the HG at such low boost. At least not the HG specifically, but you can worry about the stock head bolts. People have made 600 whp on stock HGs with ARPs. A little knock or a couple degrees too many on the timing puts WAY more stress on the HG than the boost pressure. But now I'm babbling...

Cams will definitely help, especially on pump gas, as I always say. You can make the same power without them, you just have to run ~3 pounds more boost to make up the difference. I would get the boost spike sorted out, since that occurs at peak torque it can cause a little knock that will decay slowly and ruint he rest of the pull (knock retard is reset on throttle lift, FYI, except on version two of DSMlink where it is also reset by the clutch siwtch for NLTS purposes). But, most of this can be remedied by pulling some timing around the rpm of the spike. That will only work on a "typical" pull of course, getting into at 5k rpm for example will leave you in the same boat.

I'll take a look at the log when I get home, I can't install software on the work PCs any more. Bastards... The HP numbers do seem low, especially for a dynojet, but I'm there is good reason for it. And now you have a better sense of how much those cams and probably some other troubleshooting will help

[kjewer1]

Just checked out the logs. Notice that on every pull the knock started soon after you hit peak cylinder pressure and timing just starts to ramp. You start pulling out the bulk of the timing (the 3 degrees) after this point by a few hundred rpm. My guess is that if you dropped timing from say 3k to 5k you could leave the timing stock at the higher rpms and make more peak power and end up with a better curve.

11.5 is leaner than I like to run on pump gas, but looking at the dyno chart it looks like you are really running 12:1 most of the time. Is that correct or are my eyes and that small picture playing tricks on me? If so I'd add some fuel, especially in the midrange rpm where knock is more likely to start. You're logs show closer to 10.5:1 though, and boost est at 6k is pretty much what you say it was set at, so that should be relatively accurate.

I would start with timing changes and see how that affects things. I Think you'll find most of the gain there. Remember that where you see knock in the logs is not necessarily where it is actually knocking, just where the ECU feels it should be pulling timing. It's very possible that the knock event that starts at 4500 or so is over by 4800, but the ECU keeps pulling the timing to redline. It doesn't show the classic downward "stairstep" decay trace, but it would still be my first bet especially with a boost spike. A couple degree out early can help the whole gear.

[LouieAWDTSi]

So you ran 16 psi? Isn't that way low, shouldnt you be fine with like 22-25psi with your set up or?

[Thor06]

Sorry to see that you didnt make the numbers you want, but 300 ft lbs of torque is pretty good. Good luck with more tuning and getting the numbers you were shooting for.

Sorry for the OT/thread jack, but how do you guys know what to do when you tune? I checked yesterday and I do have an EPROM in my 90 talon (thank god) and DSMlink will probably happen after the head rebuild (might as well since the head will be out anyway), head gasket, and arp headstuds and before anything else. I want to be able to see if anything is going wrong and fix it before I get any more performance parts on it.

[crunchymilk55]

Read the tuning guides that are around. It sounds simple at first, but can get complicated quickly

[crunchymilk55]

Kevin, thanks for the advice. The wideband on that dyno reads about .5 too lean, this is from the dyno owner himself. There was also still plenty of black smoke that was obviously fuel.

I'm confused about where to make the timing changes. On the dyno the turbo spools later obviously. But this dyno is supposed to have a heavier load than the street. Should I make these timing changes at the rpm according to the dyno or according to the street. I hit max boost on the street around 3.2k, way different than the dyno obviously.

Sorry it took so long, I've been really busy today.

[kjewer1]

The dyno always loads the car less than the street (unless its a load bearing dyno and you are holding it one rpm at WOT), so boost threshold is always higher. I accounted for this above when I suggested to start taking the timing out around 3k rpm. Looking at dyno6 I would pull timing down to minus 3s from 3k to 5k (some sliders are already there) and see what that does for knock. If it goes away, start to add it in slowly from 7k downward until you can get everything above say 5500 back to zero, leaving something of a ramp from the minus 3 at 3k to the zeros at 5k-5500. That's the basic process, but you'll have to adjust it slightly based on what works. I have found that the 2g timing curve does pretty damn well as is and I make very minor adjustments to it (for pump gas anyway). It seems that whenever I can't run zeros something else is wrong (dirty combustion chambers, bad airflow metering/fuel delivery, etc). HP will always be low at a given airlfow level on pump gas, it's just the nature of the beast. Race gas will allow you to run the AFR and timing values needed to get the "normal" HP that airflow level would dictate.

[crunchymilk55]

thanks. I'll take -3 out where you said and try to get the rest back to 0. Hopefully it ill peak at higher than 10.