ATTN: Evo 316g situation...

[firebirdvert305]

Ok well lemme explain my situation im going through here. A couple of days ago I purchased an EVO316G, I had the 14b on my car with 650's, 2g mas, fmic,3" 02 housing,3"turboback no muffer or cat, 272/272 cams...With that turbo i was having problems holding boost to redline probley due to the greater volumetric efficency of the engine now that I have cams in it. Ok so she used to spike 22psi then fall to 15psi by redline which it did, and was expected. Now onto the EVO316G its fully ported w/stock 31mm flapper, I recieved a new chip in the mail for it, it has all the goodies on it NLTS, 2g mas/650inj compensation and a real aggressive timing map, usually I see 22degrees advance with 0 knock. The car is having REAL BAD BOOST CREEP PROBLEMS, basically to the point where I cannot even go WOT. The car sputters/misfires real bad at higher rpms 5000+ showing 0 knock and 22 degrees on pump 93 oct. I decided to gap the plugs smaller they were at .028 and I then regapped them .025 and it seemed to have helped me a little bit. I use 93 pump gas, I dont know whats causing this backfire/misfire situation? The fuel trims seem to be rich...the low trim is 81.2% the mid is close to 100% and the high trim is 97ish give or take. I dont know if its doing this misfire situation b/c of the raising boost pressure or what? I need help on this problem, as im totally stumped on what else it could be. Could it be high AFR's or boost creep doing this?

 

[2gredspyder]

I would try to look for boost leaks and change the plugs for colder ones.

 

[dsmsucks]

Your exhaust basically has no restrictions, so you should expect some creeping from the
e16g. I would suggest porting everything( o2 and manifold). U could also try a dump tube.

 

[firebirdvert305]

Ive been using BPR7ES plugs which has been working great on my setup. The manifold on it now is a ported evo 3 manifold, the 02 housing is a tubular piece...heres a pic of the setup.

http://imageigloo.com/viewer.php?id=3903newlaser2.jpg

 

[2gredspyder]

How much boost are you trying to run?

 

[firebirdvert305]

pump gas 20-22 110oct. 24-26

 

[chet]

have you ported the exhaust housing properly?

on setups that are capable of flowing more air...porting the exhaust housing makes boost creep less likely.

 

[Dream On]

If that fails, just get an external wastegate.

 

[wazzelby]

Have you tested the wastegate? Any chance it is not functioning properly? As for the sputtering and such, the 16G will definately flow more air at the same boost level so it may just be a matter of tuning. When I switched from a 20G (at about 20PSI) to the Holset (at only 17PSI...being conservative) I saw ALOT more airflow. I had to completely re-tune. WHere the old tired 14B was dropping off, the 16G is still going strong.

 

[firebirdvert305]

Yea well ive logged the car and ive come to the conclusion that im seeing 22* of advnace by 3500 rpms...with 0 knock....but the reason why im showing 0 knock is most likely due to the fact i turned the mbc all the way in (to control the creep i was having) so with that little airflow it wont knock, but as soon as it starts to creep to 20ish by 4500ish rpms...it will start to knock (still at 22* advance). So what im going to do is get a less aggressive chip made for the car and see what happens...Hopefully boost will become a little more friendly, and only creep 2-3lbs. If it still creeps 10+psi, il probley go external. Il keep you guys informed.

 

[wazzelby]

Definately too much timing that early. Does the timing dip at all when boost comes on? It should drop to somewhere in the 11-12 degree area then climb back up. Good idea to get the chip redone a little less aggressive. That should help alot with the driveability. Boost creep is a whole other issue.

 

[firebirdvert305]

Nope the timing issue is locked in soon as the TPS reads 100%, basically soon as it goes WOT, the timing will lock in at 22* advance. Il get a new chip tomorrow and let you guys know what happens.

 

[TheClaw]

When I put my e316g on I had CRAZY boost creep. I couldn't go past 4k RPMS or it would shoot up to 35+psi

yeah

So the next day I bought a tial external gate and completely got rid of the creep. It's now rock steady at 21psi from 3k to redline.

 

[kraka]

When I put my e316g on I had CRAZY boost creep. I couldn't go past 4k RPMS or it would shoot up to 35+psi

yeah

So the next day I bought a tial external gate and completely got rid of the creep. It's now rock steady at 21psi from 3k to redline.

Thats one solution...For me I just had a dsm shop port my wastegate path, from the inlet to the outlet, completely smoothed out

 

[firebirdvert305]

TheClaw do you have any pictures of your setup? What size external gate are you running 38mm? Also how did you mount yours, off the manifold or off the 02 housing?

 

[Enraged78]

Firebirdvert,

I wouldn't go external. The problem you are having is what many, many people have experienced when stepping up to an Evo III 16G with a large, open exhaust. The problem is not in your O2 sensor housing, it is in the exhaust inlet and wastegate outlet of the turbo. Read the Oldman method of porting for boost creep. It's perfect for your situation. You need to port the Evo III in three places to eliminate boost creep. First, behind the wastegate flapper arm so that the flapper can open all the way. Second, port the wastegate passage itself slightly. Third (the most important) is to remove material on the exhaust inlet before the wastegate flapper door. The idea here is to create a decreasing radius inlet, so air does not have to make a 90 degree turn to exit through the wastegate passage. A few hours with a die grinder and a good bit make all the difference in the world.

My Evo III would creep to 24PSI in warm air, which is pretty bad. After porting, I can turn my boost controller all the way down and hold 10 PSI to redline if I so choose. I'd hate to see you spend the money on a manifold, external gate, and dumptube just to get rid of a very common problem.

Good luck,
Matt.

 

[BISHILVR]

Yeah, tons of people have handled the problem with simple grinding of the hotside housing.

 

[KeltonDSMer]

Just make sure not to remove too much material in fron of the wastegate flapper because that will cause turbulance for the exhaust spinning the turbine. Porting the housing is great, but too much in front of the flapper will just cause the exhaust to be directed at the WG instead of efficiently spinning the turbine.

 

[2gAWDTalon]

As stated, 22 degrees as soon as boost hits is way to much. 22 degrees peak is great if you dont knock, but you want a nice smooth steady timing curve. For example, I usually see a peak of 22-23 degrees advance... I just opened a log to check and on this log:
@ 5411rpm I had 15.1 degrees, @6178 I had 19.3 and I did not get to 22.1 until 7310rpms.

I think your creep issue can be solved as stated by proper porting, if you get fed up and want to go external, do it like the pic I showed you of mine on ORLDSM, works like a champ!

This is just a question for someone wiser than I: Could the extreme advance in timing make the turbo spool up faster, thus causing worse boost creep? My line of thought on this comes from Anti-Lag in DSMLink, IE: with just a studder I build less than 10psi, but with the Anti-Lag set on 10degrees ATDC I build 20psi. I may be totally off on this, just a thought.

 

[RipperXX]

I am currently in the process of swapping over to a external 38mm Tial that routes back in just before the DP with a tubuler O2 houseing.

I was haveing the same problems, I would set my boost to 15psi and it would go to this, then creep to 18or so, then 20 then sky rocket to 27+ So I said screw it, im going to make sure this doesn't happen again and look good doing so. So I called forth the might Tial and we will see what happens in a few days.


For the poster, I would assume that locking in your timeing wasn't a..great idea and could be the problem, but doesn't quite sound like it to me. As I just installed a DSMLink not long ago, and noticed even with my uncontrolable boost, my timeing stays right around that area. 18-23* advance with once in a while .4 to .7 degree's of knock. Corse im still with the stock 90 cams soo... that may be why im still getting so much timeing. Which was proably more due to the 6 month old gas than anything.


P.S. About this porting thing... obveously I have to remove the internal gate, but once thats done, would it be best to tap and put a bolt in the hole where the shaft to the flapper was (to move it via actuator) or weld it shut? Any way back to porting, im afraid to do much porting infront of the stock flapper location, I only intend to open up the hole as much as I can, since im going external with a 38mm Tial I didn't figure theres alot to gain by porting infront of the passage to aim exhaust at the WG.

But im wondering how much should I port the WG passage out to? I had a 34mm flapper installed which on a 32mm hole didn't make much since I guess, but can I port it much more than 34mm? I just want to take full advantage of the external since I spent the $ for it. Is there anything to gain by trying to open it up to say 36+mm or does that just make it more likely to crack? I dont start port work untill tomarrow, and havn't looked at it exteramly close so... im not sure how much it can even be opened.

 

[firebirdvert305]

Hey ripper just make sure you post pics of your engine bay after you mount the external. Are you going to be running it off the #1 runner or collector or 02 housing? Did you go tial 38mm? Im going this same route.

 

[RipperXX]

Im mounting it onto a tubuler O2 houseing, and yes it is a 38mm tial. Also since the car was just painted i'll be sure to post lots of pics.



Just to clairify earlier I was asking the best way to port the waste gate passage.

 

[oldman]

Im mounting it onto a tubuler O2 houseing, and yes it is a 38mm tial. Also since the car was just painted i'll be sure to post lots of pics.



Just to clairify earlier I was asking the best way to port the waste gate passage.

You will have to port it as if you were porting an internally gated one making an O2 mounted external almost pointless.

 

[BISHILVR]

If you are using an external then why bother porting the wastegate area that you wont ever be using?

 

[oldman]

If you are using an external then why bother porting the wastegate area that you wont ever be using?

Because his wastegate is mounted off the O2 housing. Although better than a plain old internal o2 dump due to lack of flapper, it is still not a gaurentee without porting because it is the flow characteristics of the wastegate path in the turbine housing that contributes the most to boost creep, not the dumping capacity of the o2 housing. This is why I think an O2 mounted external wastegate is pointless for the purpose of solving boost creep because the required porting alone is probably enough, An o2 mounted external become worth while in high power applications where boost creep is no longer an issue but keeping the internal flapper shut is.