[Jerain]

Originally Posted by Sgop335

Good hp, but lots of throttle closure. Wonder if the "before" log was similar or is all the "extra" air doing this

Yeah first few miles on this setup, cold outside, not so smooth roads,... Can be various factors but throttle closures are a form of boost control in mhd I have read. Will get a custom map in spring targetting more boost on the stock turbos, so if they eventually blow I can get hybrids.

The wgdc is around 45 where it was around 65 in a similar map with just stock intake...

[RSL]

Find it really hard to believe venting those dropped DC by 1/3. Didn't fix any boost leaks, clean filter, etc. at the same time? Logs of the same map at 65%?

You've also broken the vacuum that makes the snorkel/ambient supply function, so expect some higher IATs, especially when summer hits.

[Sgop335]

Originally Posted by Jerain

Yeah first few miles on this setup, cold outside, not so smooth roads,... Can be various factors but throttle closures are a form of boost control in mhd I have read. Will get a custom map in spring targetting more boost on the stock turbos, so if they eventually blow I can get hybrids.

The wgdc is around 45 where it was around 65 in a similar map with just stock intake...

Yea, that difference seems high. Cant think two 1 inch holes made such a significant difference esp w stock inlets. And 65 "before" implies a boost leak or something.

[Jerain]

Originally Posted by RSL

Find it really hard to believe venting those dropped DC by 1/3. Didn't fix any boost leaks, clean filter, etc. at the same time? Logs of the same map at 65%?

You've also broken the vacuum that makes the snorkel/ambient supply function, so expect some higher IATs, especially when summer hits.

At the same time changed the stock filter to a K&N drop in. A regular DCI also doesnt have that vacuum like the stock intake, and I have the extra from the most cold air coming through the stock airbox. It really only is a bit like a mr. 5 intake but without plumbing a tube under the hood. I also have the BMS cowl delete to get temps down under the hood.

WGDC a lot lower compared to an E50 map that has almost the same boost levels at high rpm, around 14 psi.

It looks good enough for me an not too much in your face if I get pulled over, it sounds good and the car drives hard so for now good enough for me.

[Jerain]

Originally Posted by Sgop335

Yea, that difference seems high. Cant think two 1 inch holes made such a significant difference esp w stock inlets. And 65 "before" implies a boost leak or something.

I will do the test and replace the 2 small airfilters and cap off the holes and do some more logging and report back.

[Jerain]

After looking at more logs I think you may be right about the big difference being too optimistic. Where I got the big difference from: this first comparison is the latest setup with V8 E30 and the K&N + extra airfilters compared to the worst log with stock airbox and filter V8 E50 but around the same boost level, 3rd gear:





After this last log I did replace my boost solenoids and vacuum line next to my oil filter because I suspected a leak.

After that I have logs from around the same boost level, also 3rd gear and it does show about 8-10% more wgdc... Maybe that's more realistic.





Conclusion, next test is to take off the small filters and cap off the holes, do some datalogging with the same setup airbox and K&N drop in filter and compare those 2 before making any more statements

[RSL]

Shouldn't see much change even removing the entire airbox and there are things in tuning and the car that can effect DC without really moving boost too much (including environment changes), but the BCS and tune change was probably it. Thanks for clearing that up.

I figured if you were going to bother buying a Z4 lid, you wanted to keep it closed. Venting the intake side undoes that and pulls air in from under the hood. You'll still get the balance it can't flow from the snorkel, so may not be quite as bad as DCI, but given enough run time, will likely see higher IATs.

[Jerain]

Originally Posted by RSL

Shouldn't see much change even removing the entire airbox and there are things in tuning and the car that can effect DC without really moving boost too much (including environment changes), but the BCS and tune change was probably it. Thanks for clearing that up.

I figured if you were going to bother buying a Z4 lid, you wanted to keep it closed. Venting the intake side undoes that and pulls air in from under the hood. You'll still get the balance it can't flow from the snorkel, so may not be quite as bad as DCI, but given enough run time, will likely see higher IATs.

Yeah that has been the debate for years with FBO cars and one of the main things that held me back from a true DCI. Stock airbox gives colder thus denser air but in high rpm and high boost maybe a bit of a restriction... Thats why I am trying to make a combination here. But in springtime when the roads will be better I will do back to back testing on the same maps and report back.

[Jerain]

So after doing another test but now with the small air filter off and capping off the two holes on the inlets (so just stock intake with K&N drop-in and airscoops). First off the IAT were a bit lower, about 6-7F less at the end of 4th gear (and the outside temp are almost freezing over here).

Also the WGDC bank 1% was exactly the same, around 47% max. Also noticed that with the so called DIY BOV mod (stock DV vent to atmosphere) you lose a bit of boost in the first second(s) of WOT, so in the log clearly shows the first RPM not as easy reaching boost target. Normally that's not really a problem because the 2 stock DV vent to inlets itself improving the aircharge. Now they operate a bit slow and that first boost is lost in the engine bay. You can even hear that first part after WOT they lose some boost. Also the whp in virtual dyno are around 450whp so the same as the previous average VDs with the small filters.

Conclusion: If you want the lowest IAT (not really a problem if you have a really big intercooler), you want the best throttle response and spool up in low rpm, keep stock DV and intake.

For me as a Nurburgring driver and drifter, the low rpm torque and throttle response are more important than those few possible gained whp in the really high rev range.

Does anyone has real world experience with the Turbosmart DVs? Seems in testing they respond quicker and hold boost better than the stock DVs?

[Sgop335]

Originally Posted by Jerain

So after doing another test but now with the small air filter off and capping off the two holes on the inlets (so just stock intake with K&N drop-in and airscoops). First off the IAT were a bit lower, about 6-7F less at the end of 4th gear (and the outside temp are almost freezing over here).

Also the WGDC bank 1% was exactly the same, around 47% max. Also noticed that with the so called DIY BOV mod (stock DV vent to atmosphere) you lose a bit of boost in the first second(s) of WOT, so in the log clearly shows the first RPM not as easy reaching boost target. Normally that's not really a problem because the 2 stock DV vent to inlets itself improving the aircharge. Now they operate a bit slow and that first boost is lost in the engine bay. You can even hear that first part after WOT they lose some boost. Also the whp in virtual dyno are around 450whp so the same as the previous average VDs with the small filters.

Conclusion: If you want the lowest IAT (not really a problem if you have a really big intercooler), you want the best throttle response and spool up in low rpm, keep stock DV and intake.

For me as a Nurburgring driver and drifter, the low rpm torque and throttle response are more important than those few possible gained whp in the really high rev range.

Does anyone has real world experience with the Turbosmart DVs? Seems in testing they respond quicker and hold boost better than the stock DVs?

I have the hyperboost dvs similar to turbosmart. These have larger vent areas than stock and dont leak. Lately i have experimented running just one dv and blocking the other dv hole. I kept an eye on boost mean and found it no different than value with two stock dvs, especially when taking your foot off. Its 19-20psi spike. This has given me the best low rpm torque so far.
will try to post a pic.

[Jerain]

Originally Posted by Sgop335

I have the hyperboost dvs similar to turbosmart. These have larger vent areas than stock and dont leak. Lately i have experimented running just one dv and blocking the other dv hole. I kept an eye on boost mean and found it no different than value with two stock dvs, especially when taking your foot off. Its 19-20psi spike. This has given me the best low rpm torque so far.
will try to post a pic.

That's funny because yesterday what I did was put back the two small airfilters on the inlets and block off one dv hole on the cp. The remaining dv did seem to close sooner and ofcourse blow off harder. The car had a bit less turbo lag then with 2 VTA dv's, but I still think that my OTS MHD map V8 works best with the stock dv's recirculating, I think they keep the turbo's spooling a little better down low. The overall grunt down low feels better with stock DV is what I mean. But with the small airfilters on the inlets I do feel a bit more grunt up high in the rev range. But as I said previously for me as a drifter I like more grunt down low, when I do drifting and give small dots of throttle the lag needs to be as small as possible and each time the dv's blow off in the inlets keeps the turbo's spooling a little bit better in between throttle inputs.

So I bought 2 almost new stock dv's from a guy who switched to BOV cp, because I cut up my original stock dv's (with 150k miles on them) these new ones have just 20000km, he has a bill for them.

I see in your signature you have a homemade tune, but when I open your datazap it doesn't seem to have high boost or timing, I can recommend you V8 E30 or E50 MHD, it targets around 18.5 and tapers to around 16psi and has timing around 13 to 12, great power on those maps as you can see in my last virtual dyno, around 450-460whp!

[Sgop335]

Originally Posted by Jerain

That's funny because yesterday what I did was put back the two small airfilters on the inlets and block off one dv hole on the cp. The remaining dv did seem to close sooner and ofcourse blow off harder. The car had a bit less turbo lag then with 2 VTA dv's, but I still think that my OTS MHD map V8 works best with the stock dv's recirculating, I think they keep the turbo's spooling a little better down low. The overall grunt down low feels better with stock DV is what I mean. But with the small airfilters on the inlets I do feel a bit more grunt up high in the rev range. But as I said previously for me as a drifter I like more grunt down low, when I do drifting and give small dots of throttle the lag needs to be as small as possible and each time the dv's blow off in the inlets keeps the turbo's spooling a little bit better in between throttle inputs.

So I bought 2 almost new stock dv's from a guy who switched to BOV cp, because I cut up my original stock dv's (with 150k miles on them) these new ones have just 20000km, he has a bill for them.

I see in your signature you have a homemade tune, but when I open your datazap it doesn't seem to have high boost or timing, I can recommend you V8 E30 or E50 MHD, it targets around 18.5 and tapers to around 16psi and has timing around 13 to 12, great power on those maps as you can see in my last virtual dyno, around 450-460whp!

I dont have easy access to e85 to use e30. I fill up about 15gal in tanks occasionally and use upto 2 gal each time i fill up, that results in e20 for my maps. My load is pretty much maxed out for the stock lpfp pump, not upgrading and so is timing. Works out fine and datazap even for me is about 420whp.

[Pinscher]

Originally Posted by Jerain

So first day it was a bit dry and cold here, so first datalogging with this setup (details in signature). Car felt very fast, more grunt up top. Drove the V8 E30 map and my WGDC dropped a massive average 20% in high rpm!! Car breathes much better now, makes lovely turbo spooling and BOV noises! I can recommend these mods to anyone!

My best Virtual dyno showed 461whp on smoothing 5 with just 10 liters of pure 100% ethanol mixed with 30 liters 95RON. Even if those numbers seem a bit optimistic, I'm very happy. I will be running the E50 or E60 map in spring and summer so will be even better.

https://datazap.me/u/jerain/mhd-v8-e...data=3-4-20-28

Can you share a picture of your mod so the less imaginative of us can understand your awesome, picture book style?

If you approach this as a max air flow capacity problem, and you think your DCI's air flow capacity is being maxed out then yes, two extra intakes would help to alleviate your air flow restriction. I don't know how much air the engine is sucking in at red line, or how much flow DCI offer, but it's a place to start for knowing if more is needed or not, though you'd think that any DCI would have more than enough flow capacity or flow rate to feed the N54 car all the way to Redline. Does yours?


Also consider that if the smaller filters have more air resistance(less flow), they won't be used until after the DCI filters have maxed their flow capacity. Air, like water, will always take the least restrictive path