Max Boost on 93 Octane?

[hawkfan]

I don't want to start any debates here, I just want to hear other TR guys experiences with the max boost they were able to get out of straight 93 octane gas for a sanity check. I finally got my T together and have taken it for a few drives. I was setting up the boost controller and I'm currently getting ~20psi of boost at WOT with no knock on the knock gauge or any KR on the scanmaster. My original goal was 18-19psi max. I was honestly expecting to see some lights flashing and at least some KR on the scanmaster at this point. Is there any way for me to test the knock sensor to make sure it's working correctly??? I've turned the boost down a hair until I can figure this out. This is what I have in the T right now.

TE-44
GN1 cold air intake (came with car)
RJC power plate
PTE SLIC
Pypes exhaust with 3" high flow cat
Boostvalve manual boost controller
TT 93 chip burned for mods

 

[earlbrown]

The exact answer to your knock question is 'it depends on a lot of stuff'

as far as testing the knock sensor, bang the block with a metal rod. if you don't see knock, there's a problem with the circuit.

 

[hawkfan]

The exact answer to your knock question is 'it depends on a lot of stuff'

as far as testing the knock sensor, bang the block with a metal rod. if you don't see knock, there's a problem with the circuit.

So I should be able to 'tap' the engine at idle and the knock gauge should work?

 

[getdowngranny]

This happened to me on my old GN and I pounded on it for a few months till I pancaked a rod bearing. Turned out to be a bad knock sensor. I don't know the exact way to properly test it but I am sure someone here will know how. I would try tapping near the sensor while the car is running.

 

[deezdad]

20# is impressive for a slic on 93, good for you man .. Subscribed

 

[hawkfan]

Got it. I'll keep the boost down until I figure out if the knock sensor is working right. If it is, I'll keep tuning and see how far it goes, and then tune it back down for some safety margin.

 

[deezdad]

Fwiw I believe turbodave is running 20# plus on 93 only difference being he has a fmic... He has posted timing/boost specifics per gear in the past that you could probably dig up for comparison..

 

[robzombie]

I tried the bang the manifold thing and it didn't work for me, so I bought a new sensor and still no knock.

I bumped the timing in the chip and then I got some knock and that was with the old sensor back in there.

I forgot what thread I read that had a more in depth description of how to test it but it wasn't just hitting the manifold at idle, that much I remember.

 

[hawkfan]

I tried the bang the manifold thing and it didn't work for me, so I bought a new sensor and still no knock.

I bumped the timing in the chip and then I got some knock and that was with the old sensor back in there.

I forgot what thread I read that had a more in depth description of how to test it but it wasn't just hitting the manifold at idle, that much I remember.

Thanks. I'll have to do some digging to figure out how to test the knock sensor. I won't be able to tune this thing until I get that sorted out.

 

[kidglok]

you really have to hit the back of the motor pretty hard to set it off, and im not sure on the stock ecm but you might have to be in drive for it to register

 

[mgmshar]

From memory, with the stock ECM, the sensor can be tested in park. But, the throttle must be open (i.e. not idling, but being pressed a little bit) and RPMs should be above idle. Probably easier to do with two people. One to sit in the car, press the gas pedal a bit, and read the scan master. The other can tap the engine block with a hammer and long screw driver.

Edit, see post number 3 in this thread.
http://www.turbobuick.com/forums/threads/how-can-i-tell-if-my-knock-sensor-is-working.224660/

 

[Joeld]

i will be doing the same as you
i am expecting around 17
i am looking forward to seeing how much i can get
i am stock other than 340 fuel pump and hotwire kit and boost controller
joel

 

[hiboom]

18 is about all I can get on straight 93 if temp outside gets in the 90's then i'll start seeing a little knock at 18 If i spray a little alky 23-24 no problem

 

[TurboDave]

Ya, in the right circumstances, 20+ is attainable. I keep my 86 at around 20 but only in 1st and 2nd gears. It's electronically pulled back by the Translator Pro to 18 in 3rd.

My 87 on the other hand is different. At 16# it starts tickling the knock sensor, but it's much closer to stock, with it's original intercooler.

 

[tbone87]

I ran 20-21 on 93 with a t t chip and stock intercooler wt a 49

 

[BIGPSI]

18-20 with an esp frt mt and a racetronix dbl pumper

 

[hawkfan]

Glad to see some other guys were able to reach 20# as well. It was only about 80 degrees out yesterday, so maybe I should tune with hotter days in mind. It was never my intention to run the car on the 'edge' anyway. I want plenty of safety margin. It was fun frying the tires in 1st/2nd gear though!

 

[aminga]

I was able to get to 18 on my stock combo (except for 60lb injectors and a TT chip). It wasn't knocking it just wouldn't go any higher (standard actuator)

 

[buickruss]

Make sure you have the right torque spec on the sensor. If you over tighten it may not work properly

 

[GNregistry]

0-15 psi, as quick as I push gas pedal and above 75 mph - I ll get up to 20 psi, no knock, FMIC, TA-49, no alky (yet), 93 Octane, no race gas! When I race on drag strip using 110 octane, I can turn boost up, maximum to 24 but my gnx replica is a daily driver with 110,000 miles driven from WI to Bowling Green, KY for GS Nationals since 2009 and from WI to Maine. Maine to KY back to WI, then fly back to Maine. Lots of bolt on mods, nothing internal to engine, original tranny. Best ET/MPH - 12.396 @ 109 mph using 245/50/16" Kumho Street Tires as seen in my photos and 1.806 60' time on same tires...