[Iceberg3232]

Hey guys,

Let me start this post by saying that my ONLY intention in making this post is to hear other people's opinions regarding this situation.

My car is an 08 XI FBO running E60 with RB turbos and a recently installed inlet kit (vendor will remain nameless). Before the inlets, I was running JB4 with a custom wedge backend. I dyno'd 502/521. Since that time, I've switched to Cobb, worked with Wedge & Buraq to re-tune after the inlet install and went back to the dyno.

Both dyno's are AWD dynojets, although the first reading came from a shop in PA while this most recent is in TX.

Here's the disappointment: this most recent dyno peaked at 477/495. Granted, the top end is holding more power for a larger RPM range, however, the car actually feels slower.

One other adjustment I made was the addition of the N20 sensor so I'm now running 22.5 pounds where I was previously pushing 21 or so with JB4 setup.

So how is it I'm running more boost, with less restriction from the inlets, and making 25 less wheel? I understand every dyno is different, however, I'm not buying the fact that this is the cause. The inlets 'should' have added 30-40 wheel...instead, I lost 25 whp.

Confused and frustrated...all thoughts welcomed.

[Newguy123]

have you done any 60-130 pbox testing before/after on same stretch of road? doubt its slower, most likely the first dyno you were on was a panty dropper. those numbers seem way too high for stock inlets no offense esp for an XI that has more drivetrain loss

[alexg212]

The dyno could be the cause. I've seen greater than a 25whp variance between say a mustang dyno, and a dyno jet.

[csu87]

Originally Posted by Newguy123

have you done any 60-130 pbox testing before/after on same stretch of road? doubt its slower, most likely the first dyno you were on was a panty dropper. those numbers seem way too high for stock inlets no offense esp for an XI that has more drivetrain loss

Those numbers were kinda low to begin with, since he has RBs and an e60 mix.

However OP, without any kind of baseline on either dyno, it is hard to compare them to each other, and to any other dyno sheet you see. There can be anywhere from 10-20% + difference in dynos, and at 500whp, that can be 100+whp difference.

All a dyno is, is a tool to show you how much you have gained or to tune. It isnt the end all be all for power discussions due to the variance between them all. Go to the track and your times will tell you if you gained or lost anything.

[Antetokounmpo]

Originally Posted by Newguy123

have you done any 60-130 pbox testing before/after on same stretch of road? doubt its slower, most likely the first dyno you were on was a panty dropper. those numbers seem way too high for stock inlets no offense esp for an XI that has more drivetrain loss

500whp way too high for RB's, E60, FBO xi?? Not sure where you pulled that from. There are people making 600+whp with RB's.

[csu87]

Originally Posted by Heel Toe

500whp way too high for RB's, E60, FBO xi?? Not sure where you pulled that from. There are people making 600+whp with RB's.

He's a newguy, give him a break

[Antetokounmpo]

Originally Posted by csu87

He's a newguy, give him a break

I guess I was expecting him to know a bit more for being around more than a year and having an aftermarket turbo himself.

[Blaster400]

I bet if you reinstalled your JB4 and went with the latest MHD backend flash you'd get your power back. It's not the inlets.

[musc]

So many variables to even make a comparison. Post up logs of each dyno run.

[Iceberg3232]

Originally Posted by musc

So many variables to even make a comparison. Post up logs of each dyno run.

Only 3 variables: jb4 to Cobb with same tuner, added inlets, switched dyno although same AWD dynojet. In my head, there is a delta of approximate 55+wheel here. Expected to push 530-540 and instead I topped out at 477.

[Iceberg3232]

Originally Posted by Heel Toe

500whp way too high for RB's, E60, FBO xi?? Not sure where you pulled that from. There are people making 600+whp with RB's.

Exactly...and one of those cars is an XI running pretty much my identical setup. He made something silly like 617.

[SUHleen]

Is there an elevation difference? Different himidity/temps? Lots of factors could cause a loss...

[musc]

Originally Posted by Iceberg3232

Only 3 variables: jb4 to Cobb with same tuner, added inlets, switched dyno although same AWD dynojet. In my head, there is a delta of approximate 55+wheel here. Expected to push 530-540 and instead I topped out at 477.

Yeah but you post no logs so who really knows. You could be running 1-2 psi more post but 5 degrees less timing. Maybe you had corrections on multiple cylinders, etc. You also used different Dynojets in different states. They aren't all the same given you don't know how it was set up. etc.

Originally Posted by musc

Yeah but you post no logs so who really knows. You could be running 1-2 psi more post but 5 degrees less timing. Maybe you had corrections on multiple cylinders, etc. You also used different Dynojets in different states. They aren't all the same given you don't know how it was set up. etc.

Yeah exactly. In this situation your dyno numbers are pretty much worthless; especially when comparing 2 different setups where a multitude of changes were made from one to the other.

Let's see some logs, VBOX data, trap speeds, etc.

[Jeff@TopGearSolutions]

You just simply cannot compare another dyno. Especially from a different state, elevation, humidity, gas quality, and this list goes on and on. You also have other changes and there really is no actual control to just compare 1 to the next.

Remember, a dyno is a tool. Anyone that just goes to a dyno for a pull or number is wasting time and money.

They are to be used as a measurement and a control. The idea is to make a change and find the delta of the change. Without baselines or controls you are going to be spinning your wheels.

That being said, as other suggested... Log. I would totally disregard your original dyno as it has no merit in the equation.

[Newguy123]

misread the RB turbos part. still doesnt change my comment about dyno #1 being a panty dropper and dyno #2 being a heart breaker. like i said PBOX times before and after inlets on the same stretch of road would tell the tale and of course comparing the logs/timeing curve before and after.

[Newguy123]

Originally Posted by Heel Toe

500whp way too high for RB's, E60, FBO xi?? Not sure where you pulled that from. There are people making 600+whp with RB's.

mis-read didnt see he had RBs.

[Newguy123]

Originally Posted by Heel Toe

I guess I was expecting him to know a bit more for being around more than a year and having an aftermarket turbo himself.

yeah i was thinking he was stock turbos. didnt make sense esp on stock inlets LOL

[BQTuning]

Originally Posted by csu87

Those numbers were kinda low to begin with, since he has RBs and an e60 mix.

He's FBO 335xi

Originally Posted by Blaster400

I bet if you reinstalled your JB4 and went with the latest MHD backend flash you'd get your power back. It's not the inlets.

Hmmm

Originally Posted by Iceberg3232

Only 3 variables: jb4 to Cobb with same tuner, added inlets, switched dyno although same AWD dynojet. In my head, there is a delta of approximate 55+wheel here. Expected to push 530-540 and instead I topped out at 477.

See below............If you can collect some previous weather data during the Dyno events it will help. You can also use dragtimes.com to get a track that was closest to your orginal dyno locations for cross reference of approx data also

Originally Posted by SUHleen

Is there an elevation difference? Different himidity/temps? Lots of factors could cause a loss...

Based on current weather data:

PA Elevation 579(average) / DA 2272 estimated

Texas Elevation 1873 (average) / DA 3863 estimated

How to obtain more accurate Elevation and Density Altitude (DA)

1) Obtain Elevation http://www.whatismyelevation.com/##
2) Obtain Weather Data by Location http://www.accuweather.com/
3) Then Enter all required data into a Density Altitude calculcator http://www.dragtimes.com/da-density-...calculator.php

Here is video of how to use. This is not factoring in the fact its not the same dyno also

[csu87]

Originally Posted by BuraQ

He's FBO 335xi

FBO 335 XI with RBs on e60 blend. Should be into the mid 500s.

Pretty sure Rob hit 600+ on an XI with tft inlets and e60 on RB turbos

[BQTuning]

Originally Posted by csu87

FBO 335 XI with RBs on e60 blend. Should be into the mid 500s.

Pretty sure Rob hit 600+ on an XI with tft inlets and e60 on RB turbos

Agreed, if anyone knows more about the XI your talking about, if Im not mistaken, it would be me cause I tuned it. That guy lives in Illinois in much cooler weather / negative - DA, and lower elevation when I dynoed his car remotely.

He did 520ish whp gear to gear on the street confirmed on the dyno, and then on the dyno, and only the dyno I pushed him up to 600+ whp (which only ran on the dyno, never on the street)

Edit: Before the inlets he did 471 whp http://www.e90post.com/forums/showpo...0&postcount=37

After inlets no tuning he did 522 whp http://www.e90post.com/forums/showpo...&postcount=140

and then, I cranked it up based on his request. Keep in mind the weather conditions are negative DA conditions = more dense air = more power to take advantage of

We should not look at TFT as just an inlet ugprade, it almost an entire forced induction upgrade when compared to others and flow rate

[nyt]

You were using a factory map sensor to start with. Are you sure you were only running 21psi? You're not going to get accurate readings there, it could have been more boost. Switching from factory to N20 recently, I had to target higher boost levels (23+psi) to match the same pwm and power I was seeing at around 20 on the factory sensor. So either the factory sensor is inaccurate, or the N20 scaling is off. I haven't yet hooked up a mechanical boost gauge to check, but will eventually. Just something to consider.