Boosted Performance round 2 list

elperuano · 04-21-2013, 08:32 PM

Quote:

Originally Posted by Boosted Performance

I think it is common, it's just that nobody posts dyno charts with the boost curve. Or at least it is very uncommon.

It's common, just don't think anyone has figured out how to hold it steady to redline. My chart is posted in the sticky FI finished builds. But no boost chart jus hp/tq

Boosted Performance · 04-21-2013, 08:35 PM

Quote:

Originally Posted by elperuano

It's common, just don't think anyone has figured out how to hold it steady to redline. My chart is posted in the sticky FI finished builds. But no boost chart jus hp/tq

Thank you for sharing that info. BTW. I really appreciate it.

The reason I think it is back pressure is the fact that this thing spools stupid fast. If it spools fast, you will get great low end/mid range as is the case here. But for that to happen, the top end may suffer a bit...again the case here. So if I open it up with a 1.32 housing, the boost may slow down a bit, but the boost along with mid range/top end would be much better. Not that it is bad at all now...I just like it perfect

.

m3chhawk · 04-21-2013, 08:53 PM

Quote:

Originally Posted by Boosted Performance

I am starting to think that the 370z engine at 7,500rpm flows a lot more than a V8 at 5,000rpm (for example).

Theoretical volumetric efficiency numbers:

LS1 at 5,000 RPM: 501 cubic feet per minute
LS1 at 6,000 RPM: 601 cubic feet per minute
VQ37 at 7,500 RPM: 490 cubic feet per minute
2JZ at 6,800 RPM: 360 cubic feet per minute

So assuming even a slight bump in volumetric efficiency for the VQ over the LS1, you are in the upper operating ranges of an LS1 and 25% more than a 2JZ

Mr.Squeeze · 04-21-2013, 09:10 PM

This is very interesting that boost falls off in the upper rpm's .With my car my boost holds well all the way to red line but I am experiencing backpressure.

What kind of boost controller was used?.

ENT-Z · 04-21-2013, 09:29 PM

Jason has the same controller as me, HKS EVC-S.

Boosted Performance · 04-21-2013, 09:54 PM

Quote:

Originally Posted by Mr.Squeeze

This is very interesting that boost falls off in the upper rpm's .With my car my boost holds well all the way to red line but I am experiencing backpressure.

What kind of boost controller was used?.

That is strange because a person with an even larger turbine (same kit), and less psi is experiencing boost drop. Maybe these things are not being set properly? Just a thought I guess..however the comparison in flow between the vq37 and the V8's sure says a lot.

Mr.Squeeze · 04-21-2013, 09:57 PM

Quote:

Originally Posted by ENT-Z

Jason has the same controller as me, HKS EVC-S.

So we all have the same boost controller Gale and my self got tuned by the same tuner /same dyno

Mr.Squeeze · 04-21-2013, 10:02 PM

Quote:

Originally Posted by Boosted Performance

That is strange because a person with an even larger turbine (same kit), and less psi is experiencing boost drop. Maybe these things are not being set properly? Just a thought I guess..however the comparison in flow between the vq37 and the V8's sure says a lot.

When Vince tuned my car he set my boost controller I wonder if he set Gales when he tuned his car .

XwChriswX · 04-21-2013, 10:25 PM

Quote:

Originally Posted by Boosted Performance

Just to touch on that....

I will be doing a test on the next local dyno tune comming up in a couple of weeks here to figure this boost thing out.

I have done a lot of research, and it seems that the 1.32 a/r housing may just be optimal for these engines in the high RPM's. The dyno Gale posted is with the 1.15 a/r housing, and it still spools VERY fast. Because it does spool so fast, the turbine may still be a bit of a restriction in the upper RPM's. It makes perfect sense, but needs to be proven. To do this, I will log the EBP (exhaust back pressure) on the identical housing for a local tune with the 1.15 a/r housing. This is the exhaust pressure just before the turbine housing inlet (not after the turbo). This will give me (and I will share this as I do everything) a solid idea of what is going on, and if a larger turbine is indeed the way to go. This was my suspicion with with the 1.0 a/r housing, hence the upgrade in size. It did not work out as I had anticipated.

This engine is very efficient, and flows so well (and a lot) in the 6,000 to 8,000rpm that these (smaller) turbines may be a bit of a restriction. I have spend a lot of time trying to figure this out. I have also talked to a couple of shops that run these turbos on stroked 2JZ's, and they are making 700whp with these turbos and the 1.15 a/r housings. The guys are also saying that they would not even think about going to the 1.32 a/r housings as they are "for V8's". I am starting to think that the 370z engine at 7,500rpm flows a lot more than a V8 at 5,000rpm (for example). I also have a customer making 580whp with the identical twin scroll kit on a 350z, and the boost is solid from 3,500rpm to 7,000rpm on a 350z. But then again, on the VQ35, there is no point of going any higher with the RPM's, and there is a 200cc displacement difference.

It seems like the boost holds just fine up to about 6,500rpm, and then falls a bit after that. I am not sure why the EBC is unable to hold the boost steady/flat. I will get to the bottom of it, and as mentioned will report back.

It may not be a similar problem as it is boosted vs N/A, but I am having a similar problem with my LTH's. In the low/mid ranges, it improves power greatly, but after 6500rpms power flatlines, and indeed begins to drop off. I belive the flow of the vq37 even in N/A form is very high and the LTH's aren't able to keep up, thus becoming the choke point. This flatlining was apparent in dyno's before and after tuning. With K&N drop ins and a full 2.75" CAI.

Just thought this info might help in confirming the theory the vq37 flows a Lot of gasses in the high rpm bands.

Boosted Performance · 04-21-2013, 10:50 PM

Things are moving along very well, and it is much better making this many at once. It is a bit repetitive, but that is just the way it is.

elperuano · 04-21-2013, 11:03 PM

I'm using the same hks boost controller as well

Boosted Performance · 04-21-2013, 11:12 PM

Quote:

Originally Posted by elperuano

I'm using the same hks boost controller as well

Maybe it is something in the settings then. I have no experience with it at all.

My 350z has a Haltech, and it has an on board EBC. With the RPM's the duty cycle is increased (when in open loop). So at 4,500 rpm I have 5% duty cycle and have it set in increments of 5% for every 500rpm after that, up to 25% at 6,500rpm. Boost is a flat line at 10psi. Very simple to set/use.

The car is making 450whp, with a rather small (compared to the 1.15 a/r twin scroll) .68 a/r open inlet turbine.

I will give Vince a call tomorrow and see if he has a bit of time to talk about it.

GaleForce · 04-22-2013, 04:32 AM

Quote:

Originally Posted by Mr.Squeeze

So we all have the same boost controller Gale and my self got tuned by the same tuner /same dyno

Quote:

Originally Posted by Mr.Squeeze

When Vince tuned my car he set my boost controller I wonder if he set Gales when he tuned his car .

I was looking at your graph, no drop off at all. Vince was the one to setup my EBC for the height boost tunes.

GaleForce · 04-22-2013, 04:33 AM

Quote:

Originally Posted by Mr.Squeeze

When Vince tuned my car he set my boost controller I wonder if he set Gales when he tuned his car .

We should compare settings just for fun.

Boosted Performance · 04-22-2013, 10:11 AM

So, I just spent some time on the phone with Vince.

To sum it up, the boost is nothing to worry about. The car (as you can see by the HP curve) continued to make more power with the higher boost (+50whp over spring pressure run), even though it looks like it is tapering off.

There are many variable at play (including VVEL, and the dyno MAP sensor), and since the car already made very good power, there was no need to spend a lot of time with the EBC setting to try and flatten out the boost curve. It also takes extra time to really dial in an extra few psi (small increments over base pressure) of boost with the EBC like we are trying to do here.

Vince felt like the kit performed very well and made power with ease.

Here is a better looking dyno graph as well:

So that settles it I guess.

I will still go ahead and do the test on my end to see what the exhaust back pressure is like. However, I am no longer thinking that it is a concern.

04-21-2013, 09:10 PM	#79 (permalink)
Mr.Squeeze A True Z Fanatic Join Date: Aug 2010 Location: Keystone state Posts: 1,209 Drives: 2010 370z Rep Power: 20153	This is very interesting that boost falls off in the upper rpm's .With my car my boost holds well all the way to red line but I am experiencing backpressure. What kind of boost controller was used?. __________________ Driven Motorsports Single Turbo 7675 T4 1.32 A/R 995WHP 780TQ

04-21-2013, 10:50 PM	#85 (permalink)
Boosted Performance The370Z.com Sponsor Join Date: Feb 2010 Location: Edmonton, AB Posts: 1,629 Drives: Z's Rep Power: 3383	Things are moving along very well, and it is much better making this many at once. It is a bit repetitive, but that is just the way it is. XwChriswX and sinceday1 like this. __________________ 750WHP starting @ $7,500 to the door FOR DETAILS VISIT: http://www.the370z.com/members/boosted-performance.html FB: https://www.facebook.com/Boosted-Per...6303179791462/ IG @boostedperformanceyeg

04-22-2013, 10:11 AM	#90 (permalink)
Boosted Performance The370Z.com Sponsor Join Date: Feb 2010 Location: Edmonton, AB Posts: 1,629 Drives: Z's Rep Power: 3383	So, I just spent some time on the phone with Vince. To sum it up, the boost is nothing to worry about. The car (as you can see by the HP curve) continued to make more power with the higher boost (+50whp over spring pressure run), even though it looks like it is tapering off. There are many variable at play (including VVEL, and the dyno MAP sensor), and since the car already made very good power, there was no need to spend a lot of time with the EBC setting to try and flatten out the boost curve. It also takes extra time to really dial in an extra few psi (small increments over base pressure) of boost with the EBC like we are trying to do here. Vince felt like the kit performed very well and made power with ease. Here is a better looking dyno graph as well: So that settles it I guess. I will still go ahead and do the test on my end to see what the exhaust back pressure is like. However, I am no longer thinking that it is a concern. XwChriswX, GaleForce, elperuano and 1 others like this. __________________ 750WHP starting @ $7,500 to the door FOR DETAILS VISIT: http://www.the370z.com/members/boosted-performance.html FB: https://www.facebook.com/Boosted-Per...6303179791462/ IG @boostedperformanceyeg Last edited by Boosted Performance; 04-22-2013 at 10:13 AM.

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04-21-2013, 09:29 PM	#80 (permalink)
ENT-Z Enthusiast Member Join Date: Feb 2009 Location: St. Louis, MO Posts: 460 Drives: 09 MB 6MT 370Z Rep Power: 17	Jason has the same controller as me, HKS EVC-S.

04-21-2013, 11:03 PM	#86 (permalink)
elperuano A True Z Fanatic Join Date: Oct 2011 Location: Southwest FL Posts: 1,374 Drives: G37S Rep Power: 29	I'm using the same hks boost controller as well