Do DP's add power without a custom tune?

Mr. 5 · 01-23-2008, 05:31 PM

Quote:

Originally Posted by who's ur daddy?

I believe I was the xi test mule in question. Not a huge gain, but the dyno chart I was given definitely showed gains. Something like +6 whp and +15 wtq. JBS2 was fully adapted by the time of installation of the DP's.

I'd like to see the charts if you have them.
So, you're saying that you had a JB2 before and a JB2 after and you did nothing but add DPs?

e90AW335i · 01-23-2008, 06:56 PM

There is a discussion on this issue taking place on another site as well....

(Not spamming, just another discussion for the forum members. I did the same on the other site.)

http://www.n54tech.com/forums/showthread.php?t=320

Mr. 5 · 01-23-2008, 07:11 PM

Quote:

Originally Posted by kyleh4852

There is a discussion on this issue taking place on another site as well....

(Not spamming, just another discussion for the forum members. I did the same on the other site.)

http://www.n54tech.com/forums/showthread.php?t=320

You see? Terry did the same thing!
They made power but he added the hot pill!
The DPs alone didn't make that power.

e90AW335i · 01-23-2008, 07:14 PM

Quote:

Originally Posted by Mr. 5

You see? Terry did the same thing!
They made power but he added the hot pill!
The DPs alone didn't make that power.

We wont truly know until someone does before and after dynos and only changes the DPs. I understand what you are saying though Mr. 5.

Mr. 5 · 01-23-2008, 08:33 PM

Quote:

Originally Posted by kyleh4852

We wont truly know until someone does before and after dynos and only changes the DPs. I understand what you are saying though Mr. 5.

It seems like the only before and after we have to compare is the one that I did.

e90AW335i · 01-23-2008, 08:38 PM

Quote:

Originally Posted by Mr. 5

It seems like the only before and after we have to compare is the one that I did.

As far as catted DP's go....yes, I agree.

DreX3M · 01-23-2008, 09:30 PM

FWIW, I've got the UR catted downpipes and did post my before/after dyno.

http://www.e90post.com/forums/showth...tted+downpipes

e90AW335i · 01-23-2008, 09:43 PM

Quote:

Originally Posted by dre335

FWIW, I've got the UR catted downpipes and did post my before/after dyno.

http://www.e90post.com/forums/showth...tted+downpipes

+1, Thanks for that. I did see that when I searched before....

who's ur daddy? · 01-24-2008, 01:38 AM

Quote:

Originally Posted by Mr. 5

I'd like to see the charts if you have them.
So, you're saying that you had a JB2 before and a JB2 after and you did nothing but add DPs?

Absolutely. Nothing else.

JBS2. Dyno. JBS2 with DP. Dyno.

I wasn't there when UR dyno'd the car, but have no reason to disbelieve the dyno sheet I got. Hell, if they were going to hoodwink me, you'd think they at least would give me some more power than 6whp and 15wtq!

I didn't get anywhere near the hp that the Singapore guy got. But I have a different tune and an xi.

Mr. 5 · 01-24-2008, 08:30 AM

I'm not disbelieving you; I'd just like to see the charts.

Either we have a bunch of charts with JB2 before and JB2H after or we have word of mouth.
It would be nice to see the charts.

Quote:

Originally Posted by who's ur daddy?

Absolutely. Nothing else.

JBS2. Dyno. JBS2 with DP. Dyno.

I wasn't there when UR dyno'd the car, but have no reason to disbelieve the dyno sheet I got. Hell, if they were going to hoodwink me, you'd think they at least would give me some more power than 6whp and 15wtq!

I didn't get anywhere near the hp that the Singapore guy got. But I have a different tune and an xi.

Mr. 5 · 01-24-2008, 08:36 AM

Quote:

Originally Posted by dre335

FWIW, I've got the UR catted downpipes and did post my before/after dyno.

http://www.e90post.com/forums/showth...tted+downpipes

I did notice this before I dyno'd and that's what I expected to get.
I didn't even come close.
Actually, I even posted your link in my thread:
http://www.e90post.com/forums/showth...1393&highlight

I'm clueless to the differences.
I'm not saying that you did anything weird with your graphs but remember--I chose the best curve from every dyno.

turbotko · 01-24-2008, 10:56 AM

Well, I don't think this is realy hard to figure out. By adding the DP's to a stock car you also increase the boost, which will increase the power. The added power comes mostly from the increase in boost, not from the DP's though.

With a tune, you have pretty much reached the limits of the stock turbos. So adding downpipes and the resultant increase in boost that comes with them will not add as much power.

I'm not sold on the DP's or I would have them already. On a stock car it's great, they add a little boost to the stock tune and free up some power.......but for the $$$ you could buy a piggyback that increases the boost even more and make more power.

Just my $.02

Ultimate Racing · 01-24-2008, 11:19 AM

Quote:

Originally Posted by turbotko

Well, I don't think this is realy hard to figure out. By adding the DP's to a stock car you also increase the boost, which will increase the power. The added power comes mostly from the increase in boost, not from the DP's though.

With a tune, you have pretty much reached the limits of the stock turbos. So adding downpipes and the resultant increase in boost that comes with them will not add as much power.

I'm not sold on the DP's or I would have them already. On a stock car it's great, they add a little boost to the stock tune and free up some power.......but for the $$$ you could buy a piggyback that increases the boost even more and make more power.

Just my $.02

http://www.ultimate-racing.com/BMW/3...essVSHFCat.bmp

Not much of a boost increase over stock.

Darryl
www.ultimate-racing.com

Ultimate Racing · 01-24-2008, 11:32 AM

As promised. 335xi with JBS2 before, and after installing our metal substrate high-flow cat downpipes. No other changes.

Darryl

DreX3M · 01-24-2008, 11:34 AM

Quote:

Originally Posted by Mr. 5

I did notice this before I dyno'd and that's what I expected to get.
I didn't even come close.
Actually, I even posted your link in my thread:
http://www.e90post.com/forums/showth...1393&highlight

I'm clueless to the differences.
I'm not saying that you did anything weird with your graphs but remember--I chose the best curve from every dyno.

I assure you it was the same car on the same dyno 2 days apart since it took 2 days to install the downpipes. I was there to witness both dynos.

I understand that it's difficult for you to believe the downpipes make any reasonable hp gains given the results of your own dyno.. but I hope you'll believe that I honestly saw those numbers. Butt feel is quite consistent with the results though I know that alone can't be trusted.

I too am clueless to the differences between our dyno charts.

Mr. 5 · 01-24-2008, 11:50 AM

Thanks for posting this.
So I guess we can think of it like this:

The lighter the tune, the more power the DPs make.
The more powerful the tune, the less power the DPs make.

Quote:

Originally Posted by Ultimate Racing

As promised. 335xi with JBS2 before, and after installing our metal substrate high-flow cat downpipes. No other changes.

Darryl

cn555ic · 01-24-2008, 01:26 PM

I guess an exhaust is more important than the DP's as far power gains??

Mr. 5 · 01-24-2008, 02:33 PM

Quote:

Originally Posted by cn555ic

I guess an exhaust is more important than the DP's as far power gains??

I wouldn't necessarily say that.
DPs should make more power than an aftermarket exhaust system on a stock car.

Adding an exhaust system to a car with a procede would most likely give you the same results as adding DPs. Not much to nill.

01-23-2008, 06:56 PM	#24
e90AW335i Major General 137 Rep 6,608 Posts Drives: e90 335i Join Date: Sep 2007 Location: ...... iTrader: (4)	There is a discussion on this issue taking place on another site as well.... (Not spamming, just another discussion for the forum members. I did the same on the other site.) http://www.n54tech.com/forums/showthread.php?t=320 __________________ I install all tunes, intakes, o2 simms, and most cosmetic mods. PM me for a quote.
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01-23-2008, 09:30 PM	#29
DreX3M Private First Class 5 Rep 153 Posts Drives: F97-X3M Competition Join Date: Jun 2007 Location: Bay Area, California iTrader: (0)	FWIW, I've got the UR catted downpipes and did post my before/after dyno. http://www.e90post.com/forums/showth...tted+downpipes
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01-24-2008, 10:56 AM	#34
turbotko Lieutenant 67 Rep 527 Posts Drives: 09 E90 M3 Join Date: May 2007 Location: georgia iTrader: (3)	Well, I don't think this is realy hard to figure out. By adding the DP's to a stock car you also increase the boost, which will increase the power. The added power comes mostly from the increase in boost, not from the DP's though. With a tune, you have pretty much reached the limits of the stock turbos. So adding downpipes and the resultant increase in boost that comes with them will not add as much power. I'm not sold on the DP's or I would have them already. On a stock car it's great, they add a little boost to the stock tune and free up some power.......but for the $$$ you could buy a piggyback that increases the boost even more and make more power. Just my $.02 __________________ 10 AW on fox E90 M3 with 2 pedals, gentleman’s ride 08 AW on fox E92 M3 also 2 pedals, a bit more rowdy
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01-24-2008, 11:32 AM	#36
Ultimate Racing Lieutenant 27 Rep 469 Posts Drives: 335i, Evo VIII, WRX, STi, 350Z Join Date: Jan 2007 Location: Toronto, Canada iTrader: (2)	As promised. 335xi with JBS2 before, and after installing our metal substrate high-flow cat downpipes. No other changes. Darryl
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01-24-2008, 01:26 PM	#39
cn555ic 441 Rep 18,331 Posts Drives: 335i Join Date: Jun 2007 Location: US iTrader: (6)	I guess an exhaust is more important than the DP's as far power gains??
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