Before I get flamed, I have searched and read through several threads on this topic, but I wanted to get some informed opinions on this...

Over this past weekend I got a little brave and decided I'd see what my car was like with the pill removed from the BCS line. There have been a couple threads about removing the pill, so I thought I'd give it a try.

The only "mods" the car currently has is a Jestr M1 flash, and a K&N filter (if that matters).

As expected, the car pulls MUCH harder with the pill removed. However, because I don't have any kind of boost gauge I don't know how much I have increased boost. I did some 2nd, 3rd and 4th gear pulls logging with EvoScan and would see as much as 9 counts of knock between 4k and 5k with the Jestr M1 flash. This scared me as in my previous logs I have never seen knock sum go any higher than 3.

So I sent an email to Jestr to see what he thinks about this, or if he would recommend reinstalling the pill. But in the mean time I went through my Jestr tune and added some fuel back in to the areas where I'm seeing the knock.

After these changes to my fuel map I'm now back to seeing no more than 3 counts of knock in any gear. I've read that less than 3 is generally considered to be safe, so I'm much less worried now that my knock count is down.

My overall question is this...

What is the safety of removing the pill in the BCS line?
I know that this can cause boost spikes, but can the Jestr tune deal with this better?
I run my car at several road course events throughout the season... is running without this pill during a extended event like this dangerous?

Thanks

EDIT: This is in MI, so I'm always running at least 93 oct. Would it be safer to add some octane boost when going to the track? Or run full race fuel?

 

It is always safer to run race gass. If you are getting some knock, it should almost be completly delt with if you run race gas. I had C16 in my car with the high boost map, and saw no knock at all. I am also runing 11.8 afrs with 23d of timing.

 

Just a fyi, I use to boost around 20 - 21 with pill at 100 duty cycle, I had to drop that down to about 80 with the pill at the solenoid removed so you probably are boosting more. Did your log show what load cell you hit.

 

Well, I'm not sure if EvoScan can accurately tell what load cell you're in... but here's what a 2nd gear pull looked like this morning...

NOTE... attached file is a .csv (comma separated value), and can best be viewed in Excel or EvoScan, but the file extension needs to be changed to .csv from .txt

 

load generally maps to boost, so 200 load is roughly 20psi of boost.

of course whenever playing with the restrictor you should have a gauge or logging real boost at least... that way you can be sure you aren't over boosting..

 

You are mistaken, the load scale is roughly in kPa, 20 psi is 138 kPa so 20 PSI is roughly 240 on the load scale. 200 is roughly 14 PSI of boost.

These equity's only count for a near stock car, any un calibrated changes to induction, cams etc will through this off, the best way to check load is to mod for real load, and a method of logging boost is a necessity when making this type of change.

MB

 

actually yes sorry my mistake, 20psi = about 240 load...

 

I think you understand now that removing the pill increases the boost level. If you're car has a very conservative tune, then it can handle a few more psi of boost without allowing knock. In your case, it sounds like your tune right up to the limit.

Overall, I would not recommend making any changes like what you've done without having at least a boost gauge to see what's happening. You're lucky that the pill probably only increased the boost a few psi. If its removal had allowed something like 5 (or more) psi, that could have been fairly tough on your motor.

 

I realized that I was taking a bit of a risk by doing this, and I know better than to listen to every little thing I see posted on the Intarweb, but there was actually a thread on here about how with a Jestr flash he actually recommends removing the BCS restrictor pill. Supposedly his flash is designed to work without the pill.

When I received my e-flash from him he said nothing about this in his email, but I thought I'd give it a try. I have also emailed him to see what he thinks about this. I trust his advice and if Jestr says, "WTF are you doing?! Put that back in" I'll certainly do so. And I may do say anyways, as I do track my car at least several times during the season so I want it to be able to hold up to sustained 'abuse'.

Thanks for your advice!

 

I recently removed my pill and have my wastegate duty cycle set to somewhere around 45 at peak boost. (I don't have access to my maps at the time of writing this)

This makes 20-21 psi and translates to around 250 load on my car.

So with the pill removed and the wastegate at less than 50% I'd say there is room to boost considerable amount higher than 20 psi.

The only danger I see is you not knowing what boost you're running. Some people have talked about spikes but I have not had any and my error correction table is set to no error correction currently (because I'm still in the middle of tuning my boost).

 

First thing I did before I even put on my exhaust was get a boost gauge, even if its just a Stewart Warner (reliable and cheap) its a must for any tuned turbo vehicle.

 

so you have no restrictor at all?

 

No pill in the line to the boost control solenoid.

 

is there two pills?

one to the BCS? one from the BCS -> TURBO?

 

There are two pills. The one closest to the boost control solenoid is the one that you want to remove to increase boost. This is my understanding of the two pills...

The pill closest to the BCS
- Removal will increase boost by about 2 psi
- Removal increases the likelyhood of boost spikes
- Boost spikes and higher boost will increase the risk of engine knock without a proper tune

The pill closest to the turbo
- Removal will decrease boost to ~10 psi when also removing the other pill
- Removal will allow finest contol of boost

Please feel free to correct any of the above information.