How far can you go with a stock or maybe modified Z4 35is N54 airbox?

[studio54]

I should be clear, the difference was only hundredths of a second. Nothing that you can perceive with a butt dyno. But it was consistently slower.

My K&N filter was brand new and it was a genuine K&N brand. I bought it on the day of the testing. The results shouldn’t change at 100-200 since the performance is relative to engine speed, not ground speed.

The number of cleats just gives an indication of the total surface area of the filter. Many people pick up a K&N filter and because they can see daylight through it they think it must flow a whole lot more, but they ignore the surface area. I’m sure there are some applications/engines that K&N perform better but I don’t swallow any of their marketing hype.

Ok so the K&N was slower than the paper filter, but was still faster than the DCI ?

Higher ground speed will provide/force more fresh/colder air in the engine bay, I believe it's a condition that could benefit to a DCI setup.

I am curious to see what results I can get on mine, so I plan to do my own tests since swapping drop in is so fast & convenient. But I will start with the BMC/K&N and not the paper filter in first like you did, since firsts WOT will be probably better (so if the paper filter is still faster running in second position, it's definitely faster )

 

[Armando1969]

You could of course go the full monty and put a carbon airbox in.

 

[Darke Peak]

Ok so the K&N was slower than the paper filter, but was still faster than the DCI ?

Higher ground speed will provide/force more fresh/colder air in the engine bay, I believe it's a condition that could benefit to a DCI setup.

I am curious to see what results I can get on mine, so I plan to do my own tests since swapping drop in is so fast & convenient. But I will start with the BMC/K&N and not the paper filter in first like you did, since firsts WOT will be probably better (so if the paper filter is still faster running in second position, it's definitely faster )

K&N was the slowest under all conditions.

Paper filter with airbox was slightly faster (and lowest IAT) if stationary for extended period before WOT. Ie, engine bay temp was significantly higher than ambient.

DCI was slightly faster if moving at reasonable speed for a while before WOT. Ie, engine bay air temp was similar to ambient.

 

[Darke Peak]

You could of course go the full monty and put a carbon airbox in.View attachment 74055

That looks amazing. But I have questions:
1. Is that the filter inside the box? It looks similar to the filter on my 103ci (1800cc) Harley. If it is flowing more than the factory filter or K&N panel filter then it isn’t actually filtering anything.
2. I am wary of any company that claim “Ram Air”. This was marketing hype of Suzuki with the GSXR in the 90’s. Proven to be completely false. I think a motoGP team showed that it offers less than 1% benefit and that was only beyond 100mph.
3. It definitely will make you faster. But only because your kerb weight is lower after they emptied your wallet.

 

[fmorelli]

IMHO you can't get enough air through that setup.

 

[Darke Peak]

IMHO you can't get enough air through that setup.

Correct. If it is filtering the air properly then there is no way it can flow enough. If it is flowing enough then it can’t be filtering.

 

[Armando1969]

My goal is 450 ps, don't expect any problem getting there with this setup. There is a guy on the German forum who got upto 524 Ps with the alpina airbox. So I think it will be enough for my purposes, plus yes I am a sucker for carbon and it sounds good wenn you floor it.

 

[Tzaks]

@Darke Peak maybe you're right. In my testing from 100-200 I was 0.28s faster and I'm sure of that because I struggled a little to beat that 100-200 PR and it simply didn't happen until the DCIs were in.

Right now I have switched to a single turbo setup, i'm in the process of building the engine so most likely won't ever come back to this but interesting findings nonetheless.

 

[Darke Peak]

@Darke Peak maybe you're right. In my testing from 100-200 I was 0.28s faster and I'm sure of that because I struggled a little to beat that 100-200 PR and it simply didn't happen until the DCIs were in.

Right now I have switched to a single turbo setup, i'm in the process of building the engine so most likely won't ever come back to this but interesting findings nonetheless.

I have been able to do some higher speed testing at some roll racing events (closed circuit, same conditions). Keep in mind that I was spending about 10-20 mins idling in a lineup waiting for my turn so I had a lot of heat soak. The race starts at 40-50kmh and I cross the line about 170kmh so I used a Dragy to measure 60-160kmh. Here are the times in seconds….

Stock filter and airbox:
5.99
6.03
6.01
6.09
6.19
6.08
6.10
6.19
6.17
6.16

DCI’s:
6.80
7.34
7.18
6.79
6.75
(Only 5 runs - event was cut short after a car blew its engine and dropped oil on the track)

Conclusion: stock filter and airbox was not only quicker but also super consistent. Considering the variations in times for the DCI’s it appears that heat soak is a killer for them. Maybe DCI would fair better if there was not extended idling before each race.

 

[Armando1969]

I have been able to do some higher speed testing at some roll racing events (closed circuit, same conditions). Keep in mind that I was spending about 10-20 mins idling in a lineup waiting for my turn so I had a lot of heat soak. The race starts at 40-50kmh and I cross the line about 170kmh so I used a Dragy to measure 60-160kmh. Here are the times in seconds….

Stock filter and airbox:
5.99
6.03
6.01
6.09
6.19
6.08
6.10
6.19
6.17
6.16

DCI’s:
6.80
7.34
7.18
6.79
6.75
(Only 5 runs - event was cut short after a car blew its engine and dropped oil on the track)

Conclusion: stock filter and airbox was not only quicker but also super consistent. Considering the variations in times for the DCI’s it appears that heat soak is a killer for them. Maybe DCI would fair better if there was not extended idling before each race.

I used to be a mechanic and the idea of sucking in hot air to than cool in down again in the intercooler always sounded weird to me. I rather get cooler air in and then get it even cooler with the intercooler, but I guess everything depends on the ambient temperature and how big/good your intercooler is.

 

[studio54]

I have been able to do some higher speed testing at some roll racing events (closed circuit, same conditions). Keep in mind that I was spending about 10-20 mins idling in a lineup waiting for my turn so I had a lot of heat soak. The race starts at 40-50kmh and I cross the line about 170kmh so I used a Dragy to measure 60-160kmh. Here are the times in seconds….

Stock filter and airbox:
5.99
6.03
6.01
6.09
6.19
6.08
6.10
6.19
6.17
6.16

DCI’s:
6.80
7.34
7.18
6.79
6.75
(Only 5 runs - event was cut short after a car blew its engine and dropped oil on the track)

Conclusion: stock filter and airbox was not only quicker but also super consistent. Considering the variations in times for the DCI’s it appears that heat soak is a killer for them. Maybe DCI would fair better if there was not extended idling before each race.

Yeah the stock air box is so much consistent compared to a DCI setup, especially when sitting in trafic for example (stock air box feeds the air from almost outside while DCI feeds air from the engine bay), no doubt, I am pretty sure about that, I noticed it without dragy measures (just with my butt dyno ) but we must say that with 10 to 20 mins idle after each shots isn't a good start for a DCI setup, so (with all respect) I don't consider your tests as good tests with so much heat soak. Otherwise do you think a drop in (K&N and K&N like) will have done worst time than the DCI in such conditions ? Cause the difference is huge. 5.99 vs 6.75 for a 60-160 km/h.
In reality I think maybe with the DCI it's possible to make a great time when moving and not letting it heat soak for 20 minutes at the first time, but just once or twice stopping, like eventually you will stop at lights or anything else, and it will heat soak so fast that a stock air box will handle and after all the stock air box will be better, so in everyday situation, the stock air box will be better, it's certain.

 

[wheela]

I have been able to do some higher speed testing at some roll racing events (closed circuit, same conditions). Keep in mind that I was spending about 10-20 mins idling in a lineup waiting for my turn so I had a lot of heat soak. The race starts at 40-50kmh and I cross the line about 170kmh so I used a Dragy to measure 60-160kmh. Here are the times in seconds….

Stock filter and airbox:
5.99
6.03
6.01
6.09
6.19
6.08
6.10
6.19
6.17
6.16

DCI’s:
6.80
7.34
7.18
6.79
6.75
(Only 5 runs - event was cut short after a car blew its engine and dropped oil on the track)

Conclusion: stock filter and airbox was not only quicker but also super consistent. Considering the variations in times for the DCI’s it appears that heat soak is a killer for them. Maybe DCI would fair better if there was not extended idling before each race.

Thanks for sharing these numbers, this is good information to see.

But sorry to hear about your motor, that sucks.

 

[Darke Peak]

Yeah the stock air box is so much consistent compared to a DCI setup, especially when sitting in trafic for example (stock air box feeds the air from almost outside while DCI feeds air from the engine bay), no doubt, I am pretty sure about that, I noticed it without dragy measures (just with my butt dyno ) but we must say that with 10 to 20 mins idle after each shots isn't a good start for a DCI setup, so (with all respect) I don't consider your tests as good tests with so much heat soak. Otherwise do you think a drop in (K&N and K&N like) will have done worst time than the DCI in such conditions ? Cause the difference is huge. 5.99 vs 6.75 for a 60-160 km/h.
In reality I think maybe with the DCI it's possible to make a great time when moving and not letting it heat soak for 20 minutes at the first time, but just once or twice stopping, like eventually you will stop at lights or anything else, and it will heat soak so fast that a stock air box will handle and after all the stock air box will be better, so in everyday situation, the stock air box will be better, it's certain.

I’m not sure whether a K&N panel filter (in the stock airbox) would have done “better” than DCI. Depends on what we define better to be….

If better = more consistent than DCI. Yes I expect it would have done better because it’s pulling the same cold air as the stock filter.

If better = lower 60-160 times than DCI. I really don’t know.

 

[Darke Peak]

Thanks for sharing these numbers, this is good information to see.

But sorry to hear about your motor, that sucks.

Not my motor. Somebody else’s motor blew up and covered the length of the track in oil. It wasn’t safe to continue the event so I didn’t get more runs.

 

[studio54]

I’m not sure whether a K&N panel filter (in the stock airbox) would have done “better” than DCI. Depends on what we define better to be….

If better = more consistent than DCI. Yes I expect it would have done better because it’s pulling the same cold air as the stock filter.

If better = lower 60-160 times than DCI. I really don’t know.

With a such delta between DCI & paper filter for your 60-160 times, I would expect the "drop in" to have a marginal time difference with the paper filter AND be more consistent than the DCI but I am maybe wrong, I need to do my own testing.

The least we can say is that 10-20 minutes idle between each (numerous) shots made this test a bit sadly irrelevant IMO.

Too bad it could have been a good test in other conditions !

Is it with stock tune btw ? (EDIT : with a such good time it's probably not )

 

[carabuser]

With a such delta between DCI & paper filter for your 60-160 times, I would expect the "drop in" to have a marginal time difference with the paper filter AND be more consistent than the DCI but I am maybe wrong, I need to do my own testing.

The least we can say is that 10-20 minutes idle between each (numerous) shots made this test a bit sadly irrelevant IMO.

Too bad it could have been a good test in other conditions !

Is it with stock tune btw ? (EDIT : with a such good time it's probably not )

I think it's pretty valid. I don't race or drive my car for anything other than getting around but I often find I'm barely moving in traffic or slowly rolling through congestion before hitting the motorways and winding the car out.

I've always though the DCIs as useless rice. The drop in performance combined with the filthy air they pick up is enough reason for me to never consider them.

 

[studio54]

I think it's pretty valid. I don't race or drive my car for anything other than getting around but I often find I'm barely moving in traffic or slowly rolling through congestion before hitting the motorways and winding the car out.

I've always though the DCIs as useless rice. The drop in performance combined with the filthy air they pick up is enough reason for me to never consider them.

I am running the stock air box and not of the DCI too but for the consistent reason mostly, I like to have my WOT consistent, but I really need to do my own testing for drop in vs paper.

For DCI, on my side, I have always felt the DCI to have a nice first WOT (especially during a cold night for example) when not heat soaked then it's true that I feel that next WOTs are not as nice (especially in summer where it's obvious, it feels sluggish or after a lot of WOT) but in term of pure performance (if we only kept best time), DCI must be not too bad, I remember Mr5 (the intake guy) made tons & tons of time testing to finally admit that the DCI made good times on its 60-130 mph tests and the difference with stock airbox was marginal.

What I meant, is that for me, it's not a valid and a optimal scenario for DCI, just my opinion.

 

[Darke Peak]

With a such delta between DCI & paper filter for your 60-160 times, I would expect the "drop in" to have a marginal time difference with the paper filter AND be more consistent than the DCI but I am maybe wrong, I need to do my own testing.

The least we can say is that 10-20 minutes idle between each (numerous) shots made this test a bit sadly irrelevant IMO.

Too bad it could have been a good test in other conditions !

Is it with stock tune btw ? (EDIT : with a such good time it's probably not )

I admit it’s not real relevant for the street, but it is relevant to me since that is the format of roll racing where I push my car the hardest.

The car is FBO, MHD stage 2+, running E50. 390whp on a Mainline dyno. Before any Merrycans says that it should be making more power; this equates to 450whp on a Dynojet. Aussie horses are bigger than US horses, just like our field mice

 

[pbondar]

Well I’ve just cancelled my much delayed ECS DCIs with ram air and just see what happens with TTE550s with brand new Mahle stock filter and box..albeit with uprated plumbing too/from the turbos..

https://www.ecstuning.com/b-ecs-parts/kohlefaser-luft-technik-induction-system/000951ecs~a/

For street use if I lose say 50 BHP but keep excellent filtration, given I do 10k miles often on gritty roads, that may be a price worth paying?

 

[RSL]

No one on any setup is remotely making or missing 50HP from an intake or filter. Add scoops to the stock intake and call it done if you already have inlets.

ECS intake isn't much better than DCI because the box isn't sealed. If anyone really thinks they need one, I have both the ECS intake and AFE SI Elite sitting in boxes for years that I'd be glad to sell lol