Car boosts higher on the dyno than on the street.

[Mikester]

As stated in thread title... Went to the dyno for tuning the other day- had Lo/HI boost set where I wanted them...

Noticed that when set to 1.0-1.1 bar on the street, the car would push 1.2-1.3 on the dyno. Kept turning it down until it was in the 1.0-1.1 range... Then when off the dyno & back on the street, it would only boost .7-.8 and need to be turned back up.

Thoughts?

Dynojet if that helps any... Does it have 'settings' that need to be adjusted for the car? I don't know squat about tuning/dynos beyond their respective purposes... Hoping a few of you smart people will maybe teach me something~

Mike

[Seraphim38]

usually on the dyno it has more time to spin the turbo up. If run in the same gear for the same RPM range on the street, the only other variable would be the load setting of the dyno.

[codyace]

check to see what the dyno loading is... I know the small dynojet we used to use is a bear as it never loaded the car so you'd have a late responding sheeet, as the turbo never got loaded to make power.

[Mikester]

^^Well, I know that dyno sees a lot of V8-powered cars making WAY more torque than I ever will... When I go back, I will definitely ask... It was more annoying than anything; if you can relate.

[ultimateirving]

^^Well, I know that dyno sees a lot of V8-powered cars making WAY more torque than I ever will... When I go back, I will definitely ask... It was more annoying than anything; if you can relate.

Im assuming its load based too, but man that would be so annoying and might explain my last dyno run why i kept havin over boost issues.

Setting the e boost controllers is so tedious and i have my response set up just right for the street..
Would be so annoying to have to change it back and forth

[Mikester]

^^LOL especially when the guy tuning is in the driver's seat and his laptop is in the passenger seat... and the Dyno display he needs to see is out the passenger window... No real way to get to it without being in the way...

I really like a simple OEM-ish look... Keep it mounted on the driver's side of the center console right under the rear defroster button...

http://farm3.staticflickr.com/2860/9033975614_645725ea78_z_d.jpg

Not that where it is really matters... but not being able to get to it until he got out of the car sucked... and I did spend quite a bit of time getting it where I wanted it on the street prior to bringing it in...

Oh well- I currently am not boosting past 1.0-1.1bar or going past 6,000rpm due to another 'issue' (thanks again for the mobile shoutout Glenn!)... so RE-setting the boost controller to where I want it without being able to tweak it where the turbine really gets going sucks even more.

All in due time. Maybe I'll give Pur a call and see if they know something about it.

[Mikester]

Okay... Just got off the phone with Omar from Nocturnal Motorwoks...

He says that there is a load setting on the dyno that should be adjusted for the car when you first pull it in (makes sense)... Basically, the overboost is caused by higher load on the engine...

Although annyoing, it's better than the car being UNDER-loaded on the dyno I suppose :)