[Ferruccio]

Suppose a car was stock, maybe had something like JB4+meth+intake (like DCI).

What kind of horsepower loss could someone expect if they go back to the stock intake?

[MilehighM3]

Stock with Jb4 meth and dci? Then back to stock intake, hmm...better low to mid range power and not much difference anywhere else. All cars like cold air to make power. Dci= hot air

[zeel]

DCI will be fine if you are already running meth. The stock box is restrictive at higher boost levels.

[Velocity26]

I think that Cobb had some data where the stock box was better than a DCI overall.

[Bakeme521]

Originally Posted by Velocity26

I think that Cobb had some data where the stock box was better than a DCI overall.

Yes, with their stg 1 tune on a bone stock car. Just throwing a DCI on a stock car won't help you. You start running high boost levels the stock intake will restrict boost levels. There's a recent thread on here with a member running stock intake with stg3 maps on a procede and you can clearly see the restrictions from the intake in the logs.

[Vwgrk1]

Tuners have thrown out the 400 whp barrier on the stock intake. Just not enough flow to support more power.

Burger tested their DCI and found that there were not IAT increases with it installed.

I'm just regurgitating info; please don't shoot the messenger.

[MilehighM3]

Sure with the hood open and a fan blowing fresh, unrestricted air into the intake on a dyno

[uniter]

Originally Posted by Bakeme521

Yes, with their stg 1 tune on a bone stock car. Just throwing a DCI on a stock car won't help you. You start running high boost levels the stock intake will restrict boost levels. There's a recent thread on here with a member running stock intake with stg3 maps on a procede and you can clearly see the restrictions from the intake in the logs.

*** This is incorrect... DCIs ended up fixing my problems entirely ***

I think you're talking about my thread... My car is running lean and only boosting 15 PSI. I'm hitting a fueling ceiling. If I didn't have enough air I'd run RICH and have EXCESSIVE FUEL.

You can see from my logs that the car hits it's boost targets quickly and everything is working well with the stock airbox.


Thread in question: http://www.e90post.com/forums/showthread.php?t=743528

[zeel]

Originally Posted by Bmw135er

Sure with the hood open and a fan blowing fresh, unrestricted air into the intake on a dyno

Plenty of air gets to the DCI's on WOT runs.

[Ferruccio]

So, if you were already in the 400 whp range with a DCI, what kind of loss would you estimate with a stock airbox and same everything else? I understand that gains won't really be seen that much on a stock tune and boost levels, though I can imagine the gains getting rather substantial with higher boost.

I've driven some cars with DCIs and really didn't like the whooshing sound. It sounds kind of unrefined. I'm sure other people love it, just not my cup of tea.

[Jeff@TopGearSolutions]

Originally Posted by Ferruccio

So, if you were already in the 400 whp range with a DCI, what kind of loss would you estimate with a stock airbox and same everything else? I understand that gains won't really be seen that much on a stock tune and boost levels, though I can imagine the gains getting rather substantial with higher boost.

I've driven some cars with DCIs and really didn't like the whooshing sound. It sounds kind of unrefined. I'm sure other people love it, just not my cup of tea.

You would likely elevate wastegate duty cycles, making your turbo's work harder.In turn you would have an increase in pre intercooler inlet temps.

The intercooler is already out of efficiency even for a stock car. IF you spray enough meth you still might make the same power, but likely a little less peak power.

I recommend atleast a drop in filter at that point as that stock intake is simply a bottleneck, imagine breathing through a straw when you need about as much air a 3inch straw could provide.

***

For the rest of the questions in this thread. When tuned for optimum power you can achieve nearly 400WHP with Tune, DCI, and methanol. The reality is every dyno is different so expect to see a gain of approx 110WHP over stock. This assumes you are tuned for maximum power, not off the shelf mapping, and have your methanol mixture right.

[Ferruccio]

Originally Posted by Jeff@topgearsolutions

You would likely elevate wastegate duty cycles, making your turbo's work harder.In turn you would have an increase in pre intercooler inlet temps.

The intercooler is already out of efficiency even for a stock car. IF you spray enough meth you still might make the same power, but likely a little less peak power.

I recommend atleast a drop in filter at that point as that stock intake is simply a bottleneck, imagine breathing through a straw when you need about as much air a 3inch straw could provide.

***

For the rest of the questions in this thread. When tuned for optimum power you can achieve nearly 400WHP with Tune, DCI, and methanol. The reality is every dyno is different so expect to see a gain of approx 110WHP over stock. This assumes you are tuned for maximum power, not off the shelf mapping, and have your methanol mixture right.

Yeah, inlet air temperatures will go up just due to that bottleneck. What I'm trying to figure out is just how much of a power loss there would be (there would definitely be one, I'm not doubting that). I'd be happy with a temporary bottleneck until a quieter intake is found. Basically, I'm looking for a horsepower quantity, or order of magnitude estimate, of the change between DCI/Stock 20? 30 hp?

[Jeff@TopGearSolutions]

Originally Posted by Ferruccio

Yeah, inlet air temperatures will go up just due to that bottleneck. What I'm trying to figure out is just how much of a power loss there would be (there would definitely be one, I'm not doubting that). I'd be happy with a temporary bottleneck until a quieter intake is found. Basically, I'm looking for a horsepower quantity, or order of magnitude estimate, of the change between DCI/Stock 20? 30 hp?

If you want a quiet intake without the sacrifice in power, Dinan cold air intake.

Or maybe Mr 5 diy style, never heard that one though.

Eitherway it's a small price to find out. Just run stock intake. Unless you are making a bet about how much power you make, just enjoy your car.

The problem is dyno's arent real world air so nobody here can tell you with certainty how much power you will make or lose.

[Bimmer305]

Originally Posted by Ferruccio

Yeah, inlet air temperatures will go up just due to that bottleneck. What I'm trying to figure out is just how much of a power loss there would be (there would definitely be one, I'm not doubting that). I'd be happy with a temporary bottleneck until a quieter intake is found. Basically, I'm looking for a horsepower quantity, or order of magnitude estimate, of the change between DCI/Stock 20? 30 hp?

10 hp

[Ferruccio]

Originally Posted by Bimmer305

10 hp

Probably a bit more with a tune, but that's just a wild guess.


Thanks for the assistance, everyone. I've heard of the Mr 5 DIY style, and seen how it plugs into the airbox, and that looks interesting, as well. I might wait a bit to see what's out there.

[longliven54]

i somewhat remember reading about dci making 10hp more near redline when compared to stock with running with meth.

point to note is low-mid end pickup goes up quiet significantly with stock box. specialy if you have been driving with dci for a while.

if you are not really going to redline your car every given moment - thats when you'll enjoy having stock box instant spool.

[uniter]

Originally Posted by uniter

I think you're talking about my thread... My car is running lean and only boosting 15 PSI. I'm hitting a fueling ceiling. If I didn't have enough air I'd run RICH and have EXCESSIVE FUEL.

You can see from my logs that the car hits it's boost targets quickly and everything is working well with the stock airbox.


Thread in question: http://www.e90post.com/forums/showthread.php?t=743528

As a correction: DCI's solved my AFRs and allowed me to bump boost up another couple of PSI. Definitely added more go

I have no idea why. But they fixed my problem.

A side note, my WGDCs don't look very different between the stock airbox and DCI... They were under 40 with the stock airbox and around that with DCIs.

[dbjb]

Interesting thread. I'm with the OP on this one...

I once used to like the intake whooshing sound. However, now that I have the PE, I only want to hear that! So, I may just stick to the stock intake with a high flow filter.

Does anything change if/when running e85 and stock intake?

[enrita]

12.73 hp ....

[Ferruccio]

It would be interesting to run a test on a demanding tune (such as an E85 setup) with a stock box vs. DCI to see what the loss is and, more specifically, to see when the peak torque is reached.

[GTstunna612]

currently on my '07 335i Sedan I have DCI with only Golf Tee Mod...currently looking for a Tune...they say with the DCI and a Tune you will make greater power the turbos will spool faster not sure about all of this I'm new to the game

[nailer335]

With how the Mr5 intake I have on my car is set up, there isnt a difference in sound from the stock intake