Ericy321

TDonnell, are you running open wastegate on yours as well or plumbing that in eventually? I think Im going to have to get mine back into the exhaust somehow because its just stupid loud right now with 3 inch exhaust and open dump.

Enthalpy

Hey guys! How's it going. I'm the EMS tuner that setup Tommy's (tibbytib) car and did the plug-and-play harness for Tyler's (tdonnell) car. I'm also coaching him through EMS tuning over the phone.

Venting off one cylinder is somewhat a no-no because you wind up with a much higher flowrate out of that individual cylinder, but only when the wategate is open. This means the AFR is a lot leaner on that one cylinder! It also means to get the wideband to read the desired AFR reading when sampling all 4 (downstream of the turbo), the other 3 are QUITE rich.

This means you are down on power on the 3 cylinders and potentially close to knocking on that vented cylinder.

If you try to compensate and add fuel to the cylinder, then it winds up REALLY rich before the wastegate is open, which kills spool and power!

Another issue that can arise is you simply can't flow the required air through that one runner to fully control the turbo. This is probably what you are hitting, tdonnell. I suspect if you figure out how to vent all 4 cylinders, this issue will go away. The reason? As you open the wastegate a large amount, the pressure in the one running drops a LOT and the waste airflow potential goes away. The pressure is still high in the other 3 runners, which is what's overdriving the turbo. Venting all 4 cylinders means you are keeping the pressure you want and establishing a sufficient waste airflow to keep the turbo's speed (boost pressure) in check.

Adding the rest of your exhaust system and/or re-merging the wastegate dump tube might also fix this issue.

This is one of the big reasons we decided on an internal wastegate for Tommy's setup.

As for boost control, no electrically-actuated solenoid-type controller in the world will fix this issue, it's purely mechanical.

As for the boost control inside the E8, I have to say, I'm VERY impressed with the E8's internal controller that Tommy is running!! I haven't fiddled with the E6's, so I reserve judgement there. I don't notice as many features on the E6's, so I don't suspect it will work quite as well. It will probably be quite acceptable though.

If you guys are looking at boost control internal to the EMS as a completely legit way to save some cost on your project, the E8's internal controller is very good! You can even add things like switches or knobs to control boost!

tibbytib

tdonnell - no prob man, just thought I would through a suggestion out. With your equipment and knowledge, yep, dont be lazy and just do it! fing02.gif You will defiantely be better off, plus, it will loook better as well.

Enthalpy- I want a button that says turbo boost with a chasing red light in my grill all the while playing back to back recordings of KITT saying: KITT

Enthalpy

LOL! Actually, that's completely feasible. I could wire up the chasing LED quite easily, the turbo button is easy, and the recordings...well...you have a powerful stereo. wink1.gif

Denisst99

finishing off the exhasut sytem will help with bosot creep but won't solve it
you def. need to put the wastegate tube on the front of the manifold wit ha smooth 90° mandrel bent tube

this will solve you're problem

tdonnell

Hey there guys, thanks for all the replies!

I just got done the exhaust and all I can say is WOW. I can't wait to post some pics of this, I am in awe of what I have done. Not to brag, but it has come out SO perfect. I had to call out of work for today due to lack of sleep and finishing the exhaust 2 hours until I leave for work. I rarely do it, but I literally have done nothing but wake up and work on the car the last two weekends straight, probably about 60 work hours, maybe 70. I am physically exhausted.

As for the open dump, I dunno yet. I kind of plan on integrating it back into the exhaust, but I won't worry about that until I fix this overboost issue.

I am off to drive it with the entire exhaust on it for the first time, I will report back with info on how bad the boost creep may remain to be tomorrow.

I am very confident that if boost creep still remains I can fix it by moving the gate flange after extending the collector. I will get a nice even flow off all 4 cylinders to ensure precise boost control.

cool.gif smile.gif

OMFG!!! This car is insane! Hahahaha, soooo fun to drive!

Any engine speed over 4000 rpm and the gate can no longer control the boost.

I can feather the pedal at about 30-40% to keep the boost below 9 psi (my fuel cut setting). It is unbelievably fast, has to be a low 13 second quarter mile.

I have to get some pics up!

I don't think I am going to tear it apart to fix the gate until this weekend, I want to drive it more! LOL.

Am I risking it at 9-10 psi? I have my afr running 11:1 under boost, with a very conservative timing curve.

BTW: open wastegate sounds awesome, definately leaving it that way for a while.

yamaha

You should be ok at that air/fuel ratio. I run alittle higher, but since your on an unopen engine, I would leave it at sub 11's. Where's the pictures man? lmao.gif

tdonnell

I need to buy a friggin camera!!!

LOL. lmao.gif

Enthalpy

Keep in mind the AFR reading is all 4 cylinders, averaged out. 11:1 is just fine if you are confident one cylinder isn't appreciably leaner. Since your airflow is much higher on the one cylinder due to the wastegate, that cylinder is also running leaner. That means the other cylinders are making up for this, putting you at least down on power, if not knock-prone.

The real question isn't your total AFR, it's that vented cylinder's AFR. If it's lean, things get hot QUICKLY and bring on detonation. If nothing else, don't boost for very long at all! Adding fuel to that cylinder will help, but it will also make the cylinder very rich before the wastegate opens, putting you down on power and killing spool.

This is all assuming your timing is appropriate. If your timing is low and your AFR is lean, that combination creates incredible exhaust heat. (It's actually a tuner's trick to improve spool).

Once you fix this issue, then you get to play! If you want to impliment this for improved spool, then set the AFR up to a few pounds shy of your boost setpoint to ~12.5 or so. Then, go rich just shy of your boost setpoint for thermal control. Do the same thing with timing. Retard it about 4-5 degrees in the low boost range, then add the timing back at your setpoint.

The car will feel a little dog-ish at low boost pressures, then HAMMER you as it reaches its boost setpoint! It really makes for a fun car, I think. Plus, it spools the turbo much faster and sooner. Just watch out for turbo compressor surge!

tdonnell

Thanks for the quick lesson Damon, lol; I am always appreciative when a tuner is willing to share his/her knowledge with the average joe. fing02.gif

Secrets are for a-holes who are money hungry if you ask me. The tuner I talked to said he wouldn't let me look at what he was doing while he was doing it even if I was paying him the money for it! It's like, give us your car, then come back in 4 hours, f-that, not me, not after all the blood and sweat I have in this car. mad.gif

I noticed what you said earlier, I will be removing everything tomorrow after work to move the gate and possibly extend the manifold. 3" pipe will work almost perfectly and I have plenty of it so only thing I might need to do is make a shorter oil drain line and extend the fuel lines that run to my ss lines near the turbo for coolant. I think there is enough slack in the oil feed line to allow me to drop the turbo 1". I will also have to shorten the downpipe but that should be easy as well.

I don't want to drop it if I don't have to (due to the gravity oil drain), but if I don't think it will be gating off all 4 cylinders very well I will definately extend it.

I haven't really taken it over 5000 rpm. Maybe 6000 twice while feathering the throttle. I can't wait until I can let her go all the way to redline at WOT. I have to be putting down mid 200 whp + even with this tune, the car is wicked fast. My cam timing must be working well as I can spool to gate pressure at 2500 rpm in 5th gear after about 3 seconds. If I am in the 4-5k rpm range, boost onset to gate pressure takes about 1-1.5 seconds. Pretty good numbers right? I didn't think it would spool until 3500, my 10.3:1 compression must be playing a large part in the spool time.

No more fun for me until the gate is repaired! sad.gif

So far this tank mpg are around 15-18.

If I fill up with 100 octane, how much additional boost could I run theoretically? Or more mathmatically, how much extra boost can you run per point increase in octane numbers?

Thanks!