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Thread: Think I went with too big of a turbo...

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Posts: 11-20 of 710
2011-08-08 04:33:27
#11
Or it could be getting false knock counts or its very light (possibly false readings) I know on my car I was running between 19-15 deg timing 19 deg at about 4500 and tapering down to 15 by 8700 and i would get just a bit of static from the knock sensor reading on the AEM.

Prior to that when i had my timing at about 25 deg at 4500 and tapering down to 21 by 8700 i was getting about 3-4 volts from the knock sensor and plugs were showing signs of detonation. Once i lowered the timing to 19-15 tapering it was just static noise on the knock not actual detonation. It was reading about .3-.4 volts. I dont know how yours displays knock on the tunercode as i never used that but if it just shows any knock and counts them as knock count then it could be static noise not really detonation. In that case you need to start adding back timing do a pull and immediatly shut the motor off and coast to the side and pull a plug and check.

You should not have knock or detonation at 0 deg on a VE even on stock compression. You should be able to clear 300-350whp on pump gas without detonation.
2011-08-08 04:39:01
#12
Im assuming your running a wideband so here is my suggestion. Tune the wot a/f ratio between 11.2-11.5:1 starting at VVL, you can go a bit leaner on the lowend to help with response. Add in timing and if your timing is that low you will probably have to add in timing and then add in fuel to keep the a/f ratio good. Do low gear pulls like 2nd gear until you start losing traction then go to third. You want to have short bursts when doing the tuning and shut the motor off like I said and check a plug, preferably #1 as its the furthest from the throttle body.

If no detonation signs then add a deg at a time until you get where you want. Your car should not feel n/a and that is usually a sign you are not running near enough timing on a turbo motor.
2011-08-08 04:46:57
#13
Might be time for a meth kit if your worried about adding more timing to the motor.
2011-08-08 05:05:09
#14
Originally Posted by Stariondriver75
When that turbo spools, it shouldn't feel NA like AT ALL.

def go with a boost leak test. Also recheck the spring on the waste gate. could be opening prematurely.

Also, if you have the fuel to do it, that turbo isnt going to show its ass untill 15+ PSI

Oh BTW, is that your boost gauge line running into the air intake below the wipers??

-Seth


Welcome to the forum Seth, awesome to see new guys helping out right of way .

I have a Tial38mm wastegate, just installed the big red spring (11.6psi). Now my boost gets up to 10, then drops to 9. I really do think it's a leak, maybe the blow of valve is opening, I never ran more then 7psi on it.

Unfortunately I'm running out of timing to reduce to go above 12 psi. Which is fine too since this is a dd, and I need it to be reliable.

Originally Posted by ashtonsser
Im assuming your running a wideband so here is my suggestion. Tune the wot a/f ratio between 11.2-11.5:1 starting at VVL, you can go a bit leaner on the lowend to help with response. Add in timing and if your timing is that low you will probably have to add in timing and then add in fuel to keep the a/f ratio good. Do low gear pulls like 2nd gear until you start losing traction then go to third. You want to have short bursts when doing the tuning and shut the motor off like I said and check a plug, preferably #1 as its the furthest from the throttle body.

If no detonation signs then add a deg at a time until you get where you want. Your car should not feel n/a and that is usually a sign you are not running near enough timing on a turbo motor.


I don't have the tune with me right now, but I'll get a map up tomorrow. Basically I took the WOT part of the map and reduced the timing by 2* per psi. Even with that the knock sensor voltages would spike up above a certain voltage (TunerCode considers that as knock).

I noticed a lot of spark blowout at 10 psi too. I have side-gaped BKR6E-N-11 plugs. Was running about .030 gap with 6 psi perfectly fine. With 12 psi WG spring I started getting bogging, thus I started gaping them down and it seems like .020 is doing fine. Now by the sidegaping tutorial, you are supposed to reduce your gap by .010, so technically I am at .030.

I just got another idea, I never checked my VVL solenoids. Searching around people are saying that the exhaust solenoid is the loud one, and since I hear my intake pitch change, maybe my intake solenoid is not kicking on. I'll check that first tomorrow (since it's the simplest).
2011-08-08 05:39:38
#15
What a/r size is your exhaust housing?
2011-08-08 06:00:50
#16
With your high compression and boost you should be running colder plugs. I use to run 7s gapped at 24 now I'm running 8s gapped at around 19 for more boost. Give it a try and see what happens.
2011-08-08 07:08:33
#17
Ahhh boyyyyy, same problem we got in our GTIR with VVL DET, VADIM the guy with that DITCH THAT LOG MANIFOLD IS RIGHT, my buddies had a T3T4 62-1 (.63 a/r) Turbo with Log on their SR20DET, work really well, went to a sr20ve head, Worked exactly how you expalin which is like CRAP, learnt on the forum that Ve's hate Log Manifolds and Small back housings, changed to A Tubular Equal Lenght Manfold and T4 .86 a/r, CAR FELT INSANEEEEE

Keep your Turbo and get a Tubular Manifold man , you wont regret it
2011-08-08 13:19:33
#18
Here is my timing map, the 90 is 10-12 psi. Notice how much timing VE's can run at 3200 rpm without knocking!


Tested each solenoid, by hooking it up to the battery directly and listening for clicking. They tested fine, though I do have oil in the right solenoid.

Bumped down the VVL engagement to 3500, now it builds boost much quicker, but still doesn't feel all that much faster.


Originally Posted by unijabnx2000
What a/r size is your exhaust housing?


Forgot to post it, 0.63 A/R.

Originally Posted by kevwal
With your high compression and boost you should be running colder plugs. I use to run 7s gapped at 24 now I'm running 8s gapped at around 19 for more boost. Give it a try and see what happens.


I had BKR7E's before, they were fairly old (from my Sentra DET), but everywhere I've read said that VE's need the -n plugs, no one really knows what the difference is. I think I'll go back to regular BKR7E's since they worked just fine initially.

Originally Posted by THE_FUGITIVE
Ahhh boyyyyy, same problem we got in our GTIR with VVL DET, VADIM the guy with that DITCH THAT LOG MANIFOLD IS RIGHT, my buddies had a T3T4 62-1 (.63 a/r) Turbo with Log on their SR20DET, work really well, went to a sr20ve head, Worked exactly how you expalin which is like CRAP, learnt on the forum that Ve's hate Log Manifolds and Small back housings, changed to A Tubular Equal Lenght Manfold and T4 .86 a/r, CAR FELT INSANEEEEE

Keep your Turbo and get a Tubular Manifold man , you wont regret it


I saw a ton of contradicting information on this, I heard that VE's have reversion issues and hence logs suck, but then I had plenty of the people say VE's are just fine (while cursing at me under their breath because I questioned their wisdom).

I want to go tubular, ram horn (don't care for equal length), but space is very limited .
Last edited by Vadim on 2011-08-08 at 13-32-04.
2011-08-08 13:46:07
#19
So you are running only 7 degrees of timing on the top end at ten psi? That is very very low, an nx down here is running with an .82 backhousing with 20degrees timing at 20psi and more could have been added.
2011-08-08 13:53:55
#20
I think you're getting scared by false knock readings. Even for me, that's some silly retarded timing.
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