How do you boost lower just cause you go to a track? Also say you did turn it up what did you turn it too? Also again YOU DONT PEAK ON 4TH GEAR!!! You only see what you taper at. SO again if you saw 23.5psi in the start of 4th gear on the track then you really are boosting at 25psi and then you would pull timing. Does this analysis make sense to you?

 

it all has to do with the VE of the engine. I have a map sensor to log boost along with my boost gauge. On the stock turbo I run around 24psi on the street with a MBC. So that means when I smash the gas @ 2k RPM it will spike to 24psi and then settle @ 21 or so by 7k.

When I go to the track to see that same 24psi I see on the street I have to crank the MBC up 1/2 turn. Otherwise I'll only be boosting 21psi MAX in 4th gear.

Then when I leave the track I have to turn the boost back down otherwise I'll be boosting 26psi on the street... which is a big no no on pump gas.

 

Ok how do you spike(peak) at 2k rpm? You dont spike(peak) till around 3800rpm.

I do understand what you are saying however, evil evo was wording it wrong if that was what he meant to say.

 

For some reason when i go to the track and run my boost is about 2-3 psi less when im going throught the 1/4 in 4th... I turn it up so by the time i shift to 4th gear it spikes about 23 and settles at 21-20 by redline.. Im not bossting 25-26 like you guys claim cause i would see a loss in mph in the top end...

 

i think the 23.5 you see is at the beginning of 4th correct?Maybe his boost hasn't started to taper as of yet. It makes some sense to me. He can hit 23.5 and have it start to taper after 5500...whether it is a roll on from 2000 or racing it should hit the same boost level by redline, correct? Maybe you are just holding boost better than we think you should.

 

Correct! When i shift to 4th and im at wot the boost goes to 23.5 and then it starts to drop by redline... It NEVER spikes 25-26 like they claim it does

 

still in the 12's


get your car realine the car and see what you get you should get 12.0 or high 11's

 

sounds about right just a couple of more tries and you'll be there.

 

Just get a set of cams/re-tune and you'll be there easy.
.

 

OMG DUDE! You would never see 25-26 because you arent even where you see peak boost. AGAIN, I simply said if you are seeing 23.5 at the beginning of 4th gear then you actually have your real peak boost set at 25-26. But you would never see it cause you will(or at least should) always be past 3800rpms. Does this make sense to you now?

For example when I race down the track. I set my boost via mbc to 22psi, however, when I actually ran the highest boost level I saw was 20 thats because when you race your rpms are up past the turbos peak point. You will never see your peak boost just the taper. So if you saw at the beginning of 4th gear a tapered boost of 23.5 then your real peak would be around 25-26.

Now if for some reason you are around 3800rpms in the beginning of 4th gear then you are a horrible drag racer.

 

IT DID NOT TAPER to 23.5, it drops to 21-20 psi at redline.. For some reason you think im holding 23.5 to redline or something.. If i was spiking 25-26 this car would have pulled timing like crazy and slowed me down up top...

Its alligned..11s? Are you crazy? I dont even have cams, I have very little mods on this car... Maybe with C16 and a 30psi spike

 

What you mean it doesnt taper? Right after you hit your turbos peak point it starts to taper which means if your peak point is 3800rpms then at 3900rpms it begins to taper. So if you were at 4000rpms in the start of 4th gear then yes you saw a tapered boost level then it continues to taper throughout the rpm band. I am suprised you dont know that. This is turbo 101 here. As your rpms go up your boost tapers more and more. So if you saw it taper again to 21-20 then thats normal.

 

Dude i never said it didnt taper.. What i meant was that my car spikes 23.5 in 4th and it drops to 21-20 at redline...

 

Again wrong terminology. In a drag racing aspect your car could never "spike" in 4th gear because you would be past where your boost spike point is which is around 3800rpm. What you saw was the boost taper and then you continued to see the boost taper through the rpms. Now 23.5psi may be the highest boost level you saw in 4th gear but it certainly isnt your peak.

And because it wasnt your peak you would have had to set your peak boost level to 25-26psi to see 23.5 in the start of 4th gear.

 

Their saying that when you shift into 4th (or whatever) you're NOT starting the whole gear over at 2000 rpms or 3 or 4000... they're saying when you shift into 4th, you start 4th at 5000+rpms, since you're coming off 7000rpms in 3rd, you don't go back down to 3000 in 4th, you START 4th at higher RPMs which is PAST your peak boost, therefore the boost you are seeing is in the middle of the 4th gear taper