[08cyber]

So I went into Yimi tuning (deal with mostly subarus) today and did some pulls on the dyno. I did a run in Map 5 (car has been driven in it for a while so it was well adapted) and got 307 and 303 to the wheels. Did a baseline run and got 260. I had some octane in it probably 98?? Seeing that I had the octane I ran map 7 and got 329 to the wheels. Obviously I have a JB4 as well as Riss Racing catless 3" DPs, DCI, and AA sport intercooler. I was a little upset with the results so I swung by my local shop afterwards to make sure the car wasn't leaking boost. We hooked the gauge up to the charge pipe and took a ride. In map 7 the car was holding 16 PSI, all good there, did multiple runs. The image of the dyno is below. I have replaced HPFP, Spark Plugs, Fuel injectors and water pump. Everything seems to be working fine.

Power curves were a little rough between 3.5-4.2 rpm but other than that a fairly smooth power band. Any ideas??? I was expecting around 370-380 possibly more with the map 7.

[Eracer76]

Its just a low reading dyno. But from your baseline, you gained almost 72whp and 85 wtq... thats not terribly bad. Did you do any logs?

[08cyber]

Originally Posted by Eracer76

Its just a low reading dyno. But from your baseline, you gained almost 72whp and 85 wtq... thats not terribly bad. What was the weather like? Did you do any logs?

No logs, it says the exact temp on the bottom of the dyno but I think around 75?

[zeel]

It's probably an octane issues as well. You need quite a bit to run map 7. What kind of mix were you running?

[Fundahl]

Did you get any logs? You can still hit boost target with a mild boost leak.

[08cyber]

I was running an Octane booster with 91 Mobile1 pump gas so Im guessing 97-98. Even without running map7 I was at 307 to the wheels in map5. I did some pulls after and the car just doesn't feel consistent. It use to pull hard when I first installed the JB4, but now it just doesn't have that same feel. I'm clueless...turbos are fine just had them inspected. Plus seeing that the turbos are mechanical it would not be intermittent.

[08cyber]

Originally Posted by Fundahl

Did you get any logs? You can still hit boost target with a mild boost leak.

No logs, I checked everything 3 times over as well as ex BMW master technician. Everything is tight, vacuums are holding pressure as well.

[Mike@N54Tuning.com]

Originally Posted by 08cyber

I was running an Octane booster with 91 Mobile1 pump gas so Im guessing 97-98. Even without running map7 I was at 307 to the wheels in map5. I did some pulls after and the car just doesn't feel consistent. It use to pull hard when I first installed the JB4, but now it just doesn't have that same feel. I'm clueless...turbos are fine just had them inspected. Plus seeing that the turbos are mechanical it would not be intermittent.

There is one problem. Octane booster is not the same as race gas. Most octane boosters do nothing at all and the best ones only raise 91 octane up to 93 octane or so. You really need to do some JB4 logs and send them in to see what's going on with the car.

Mike

[Mike@N54Tuning.com]

Email BMS a CSV log of your dyno runs and they can check boost, timing, and AFR for you. If those all check out OK then its just a lower reading dyno.

Mike

[themyst]

Add 4% to those numbers. The OP was on SAE correction.

[805beemer]

I don't know if I'd call it a low reading dyno. Yimi Sport protuned my 2004 Sti about a year ago and made 290hp and 330 tq using a cobb ap, turbo back exhaust. Seemed about average for a stage 2 sti at the time.

[08cyber]

I have contacted Terry with BMS, I'll go from there. Thanks for the input!

[Sniz]

Mike is correct, octane boosters are very poor typically.


dont even bother with them. Just run race gas or meth, or pump. dont use octane 'boosters'

[M///1rider]

Yes dont put in octane booster and you should probably be running map 2 if you have a Jb4. Dynojets do not read low there actually the highest reading dynos out there.

[Javier]

its the SAE correction, most people here dyno on STD correction.. there is the difference you seek

[5soko]

Your next step should be logs.. That will tell the full story even if you have a slight leak or pulling timing , not hitting target boost or throttle closure.. I advise everyone to log during there dyno runs.. It takes the guessing out if ant issues arise usually..

[BEAR-AvHistory]

Too much map for too low fuel quality. Map 2 should be good.

[Syndicategt]

Not sure why you are upset, 71 HP increase is fairly normal. You want bigger numbers, get meth or run real race gas (MS109).

[135Hoser]

Originally Posted by Mike@N54Tuning.com

There is one problem. Octane booster is not the same as race gas. Most octane boosters do nothing at all and the best ones only raise 91 octane up to 93 octane or so. You really need to do some JB4 logs and send them in to see what's going on with the car.

Mike

Best ones only raise it up to 91.3, per bottle. But yeah, octane booster is garbage.

[klipseracer]

Octane booster that raises the octane by 7 points is referring to points as in seven 0.1's or 91.7

[Zebra99]

Originally Posted by klipseracer

Octane booster that raises the octane by 7 points is referring to points as in seven 0.1's or 91.7

Lmao that's f'n terrible. Rip off then and it should be stated that way.

I remember using it when I put 94 octane here in Ontario and added a booster and my 1995 VW golf 8vlv at the time started to idle high lol!!
Did run a bit better I was able to keep up with a 95 civic Si coupe
Hahaha

[themyst]

Massive timing corrections will result in poor power. Re-dyno on real race gas or meth. You will likely be happier with the numbers. Make sure the dyno operator gives you a printout of your numbers in STD correction or uncorrected.

STD will read higher in hotter ambient temps and uncorrected will read higher in cold temps.