stutter box but no boost

njc1064 · 09-25-2008, 02:45 PM

I was playing around with the car today, did a boost leak test and the system has a very slow leak, nothing major. I tried playing with the studder box and it wouldnt build boost? Turned on anti-lag just to see what would happen and it only built like 1 psi. Vacuum is around 18-19 mmhg, which is odd because i have BC 272's. Also, this is with an EVO III 16g.

Any ideas?

droppinbottom · 09-25-2008, 03:23 PM

Studderbox will not build boost for you.

You will need to play areound with the settings on your anti lag to get it to build boost off the line.

njc1064 · 09-25-2008, 03:40 PM

But i shouldnt need anti-lag with a turbo so small should i? I mean, people without dsmlink launch by simply reving the car...arent they producing boost by doing this? If this is the case, i should be producing boost without anti-lag

xxShaneOmac · 09-25-2008, 03:44 PM

5k 2step nets me 7psi on the line.

webconnect · 09-25-2008, 03:49 PM

Quote:

Originally Posted by droppinbottom

Studderbox will not build boost for you.

Isn't that the point of studderboxes

njc1064 · 09-25-2008, 03:56 PM

Exactly! Thats what im trying to say! So, any thoughts on why this is? And how could the vacuum be around 18-19 mmhg with cams?

big_d · 09-25-2008, 03:59 PM

I get about 8-9 psi on an Evo3 at 5k stutterbox.

droppinbottom · 09-25-2008, 04:00 PM

Someone correct me if I am wrong but I thought the point of a studderbox was to allow you to find the best rev's to launch at.

I thought anti-lag was to build boost off the line.

Then again I could be wrong.

turbosax2 · 09-25-2008, 04:02 PM

^^ That's how I understand it too.

My brothers car with a small 16g and stock cams doesn't build boost at 3500 rpm studderbox and no anti-lag.

droppinbottom · 09-25-2008, 04:08 PM

I never remember my 16g building any boost off the line unless I used the anti-lag.

Loewen21 · 09-25-2008, 04:14 PM

I just have my 2 step studder box set at 5500 on my AEM. Nets me a cool 8 pounds off the line.

njc1064 · 09-25-2008, 04:14 PM

Hmmm, this is very interesting. Doesnt the vacuum seem high for having 272's? wouldnt it be almost impossible to get a good launch without having some boost off the line?

droppinbottom · 09-25-2008, 04:30 PM

It would be rather easy to get a good launch out of a 16g because of how quickly it spools. Personally I don't see any need in having it build boost off the line with a 16g.

CanadianTSi · 09-25-2008, 04:31 PM

The second you let the clutch out your gonna build some boost

What is your stutterbox set to (rpm?) and how long are you holding it there?

GS-T_Newboost · 09-25-2008, 04:32 PM

i am purty sure the studder box only sets the rpms to launch at. The anti lag adds unburnt fuel into the mixture which explodes in the manifold which cause the turbo to spool alot more building boost. I think playing around with the enrichment settings changs the amount of boost that is built .... I think

njc1064 · 09-25-2008, 04:39 PM

The studderbox was set at 5500 rpm and i held it down for about 10 seconds or so. Never tried actually launching, as the clutch and trans only have about 400 miles on them.

matt98eclipse · 09-25-2008, 04:57 PM

With my stutterbox set at 5500 i see about 5psi. I thought the whole purpose of the stutterbox is to build boost also.

kahl23 · 09-25-2008, 05:35 PM

Quote:

Originally Posted by turbosax2

My brothers car with a small 16g and stock cams doesn't build boost at 3500 rpm studderbox and no anti-lag.

That seems like its more a function of the RPM that the 'box is set at. Seeing as most 16g variants don't spool until after or around 3k whilst under load, i wouldn't at all be surprised that your brother sees no pressure at only 3.5k while the engine is essentially freewheeling. Looking at old DSMLINK logs, back when I was on the E3 i would see a little under 10 psi with a 5500 rpm stutter. Now with the 3052 I see over 10psi on the same stutter. To the OP, stutterboxes aren't designed to build boost, but I feel like you should be seeing some positive pressure, especially on a 16g.

droppinbottom · 09-25-2008, 05:40 PM

Quote:

Originally Posted by kahl23

That seems like its more a function of the RPM that the 'box is set at. Seeing as most 16g variants don't spool until after or around 3k whilst under load, i wouldn't at all be surprised that your brother sees no pressure at only 3.5k while the engine is essentially freewheeling. Looking at old DSMLINK logs, back when I was on the E3 i would see a little under 10 psi with a 5500 rpm stutter. Now with the 3052 I see over 10psi on the same stutter. To the OP, stutterboxes aren't designed to build boost, but I feel like you should be seeing some positive pressure, especially on a 16g.

Can I get a log of that? The reason I ask is because I can see a 16g getting some positive pressure at 5500rpm for the simple fact that the thing is so easy to spin. Now on a 3052 I would expect you to see less if any positive pressure while just sitting at the line.

kahl23 · 09-25-2008, 05:52 PM

Unfortunately I don't have a log of the 3052 on this computer, I can show you the 16g. I'll try to see if I can find another log for the 3052, but the coilpack decided it no longer liked working for me so the car is down now.

EDIT: I keep on trying to attach the log as .dat file but it won't let me, very annoying.
Apparently once you attach a file once on this forum that's it

I keep getting an error message that I already attached it in this thread:

Evo 3 16g psi with my setup help.

Second one of my posts, be sure to view GM33Bar

Black_Bullet · 09-25-2008, 06:39 PM

That weird, my e316g builds 12-13psi on the 5500rpm 2step if I hold it full throttle for a momment ...

matt98eclipse · 09-25-2008, 06:57 PM

Quote:

Originally Posted by Black_Bullet

That weird, my e316g builds 12-13psi on the 5500rpm 2step if I hold it full throttle for a momment ...

That is weird how some poeple can only get a couple psi and others can get up 12 to 13psi on the same turbo.