gm solenoid strange boost?
gm solenoid strange boost?
I still can't seem to get this thing figured out or maybe this is just the way this setup is. I added the new definations to my rom from Mrfreds recent boost post hoping that would help but it still seems to behave the same. I'm trying to acheive 27psi tapering to about 23-24ish.
Here is the deal, I can get it to hit 27psi as long as I start in 3rd gear. but when ever I start a WOT run from 1st and up all the way through 4th I can only hit about 24.5 psi. I have tried multiple changes to the MWGDC tables, TBEC tables, etc.. about the only thing I have going right is my BDEL+offset match my 2-byte load. About the only thing I haven't tried is the lean spool disable (I kinda figured that the mitsu engineers put this in for a reason
)
I have increased my MWGDC table alot from when I switched from 91 to E85 and it just doens't make much of a difference in a 1st and up pull
Hopefully more of you guys out there have got the hang of this solenoid and can chime in. Any help would be greatly appricated.
thanks,
ed
Here is the deal, I can get it to hit 27psi as long as I start in 3rd gear. but when ever I start a WOT run from 1st and up all the way through 4th I can only hit about 24.5 psi. I have tried multiple changes to the MWGDC tables, TBEC tables, etc.. about the only thing I have going right is my BDEL+offset match my 2-byte load. About the only thing I haven't tried is the lean spool disable (I kinda figured that the mitsu engineers put this in for a reason
)I have increased my MWGDC table alot from when I switched from 91 to E85 and it just doens't make much of a difference in a 1st and up pull
Hopefully more of you guys out there have got the hang of this solenoid and can chime in. Any help would be greatly appricated.
thanks,
ed
edit: just read your post over again, OOPSS
1) You wont see 27psi in first
2) If you are going 1-4, that means you wont ever really see below 5k in 2nd-4th, by that time you are out of the peak torque range, and thus wont ever see 27psi (maybe in second with the wastegate shut
)
good luck hitting 24psi at redline, even the GM solenoid cant beat the physics behind our turbo
1) You wont see 27psi in first
2) If you are going 1-4, that means you wont ever really see below 5k in 2nd-4th, by that time you are out of the peak torque range, and thus wont ever see 27psi (maybe in second with the wastegate shut
)good luck hitting 24psi at redline, even the GM solenoid cant beat the physics behind our turbo
Last edited by UCB; Aug 27, 2007 at 10:26 PM.
edit: just read your post over again, OOPSS
1) You wont see 27psi in first
2) If you are going 1-4, that means you wont ever really see below 5k in 2nd-4th, by that time you are out of the peak torque range, and thus wont ever see 27psi (maybe in second with the wastegate shut )
good luck hitting 24psi at redline, even the GM solenoid cant beat the physics behind our turbo
1) You wont see 27psi in first
2) If you are going 1-4, that means you wont ever really see below 5k in 2nd-4th, by that time you are out of the peak torque range, and thus wont ever see 27psi (maybe in second with the wastegate shut
)good luck hitting 24psi at redline, even the GM solenoid cant beat the physics behind our turbo
The GM 3port is more responsive and allows the tuner more "headroom" to properly tune the boost tables for flatter boost accross rpm range as well as being able to run more boost than the stock system. The GM 3port with a resistor is a compatible replacement for the stock 2 port boost control solenoid.
I am not sure what turbo you are using but hitting 27 PSI in 5K would be difficult. I would just set 100% MWGDC and see if it can hit it (I would also put 280ish all over the BDEL for testing purpose -- 280 - BOffset = number you want to set in BDEL)... That would be the max any way. Before you try it, make sure to put correction in so that it reduce WGDC if it does go up beyond your target...
27PSI is about 280ish load... Are you really hitting this load? 24.5 is about 264 load. I don't see TURBO upgrade in your sig... That seems way too much boost in my opinion even if you had ALKY kit in there for safety margin....
27PSI is about 280ish load... Are you really hitting this load? 24.5 is about 264 load. I don't see TURBO upgrade in your sig... That seems way too much boost in my opinion even if you had ALKY kit in there for safety margin....
Trending Topics
ok..none of that means anything when you are trying to hit 27psi in a 1-4gear pull.
There are some things you can change about our cars, the turbos efficiency range is not one of them
There are some things you can change about our cars, the turbos efficiency range is not one of them
so basicaly what my car is doing is normal? so the only time I will hit peak boost is on a 3rd or 4th gear pull? this just doesn't seem right so basicly when drag racing you would never hit max boost?
I am not sure what turbo you are using but hitting 27 PSI in 5K would be difficult. I would just set 100% MWGDC and see if it can hit it (I would also put 280ish all over the BDEL for testing purpose -- 280 - BOffset = number you want to set in BDEL)... That would be the max any way. Before you try it, make sure to put correction in so that it reduce WGDC if it does go up beyond your target...
27PSI is about 280ish load... Are you really hitting this load? 24.5 is about 264 load. I don't see TURBO upgrade in your sig... That seems way too much boost in my opinion even if you had ALKY kit in there for safety margin....
27PSI is about 280ish load... Are you really hitting this load? 24.5 is about 264 load. I don't see TURBO upgrade in your sig... That seems way too much boost in my opinion even if you had ALKY kit in there for safety margin....
I spike 24psi and ~280 load, I hold above 270 load until about 5000RPM when it tapers... ~230 load at redline.
People running high octane and/or meth will run 27-28 psi at be over 300 load
You likely wont ever see 27psi in 1st or 2nd, and not above 5k in any other gear. So yes, for drag racing, its possible to never hit peak boost.
Thanks for sharing... That is a difference from one who has experience versus using a simple math (I'm a n00b : ) )...
I only used Load to PSI conversion (X-Baro)*0.145 = PSI. So, X being load would be x (Load) = PSI/0.145 - Baro.. I used 100 for Baro as an estimate...
But, it's good to know that only high OCTANE can see the load...
I used this method on my MR for tuning boost (2 byte load) for 93 OCT and was very close to where it wants to be.... (Used it to set the BDEL)...
I only used Load to PSI conversion (X-Baro)*0.145 = PSI. So, X being load would be x (Load) = PSI/0.145 - Baro.. I used 100 for Baro as an estimate...
But, it's good to know that only high OCTANE can see the load...
I used this method on my MR for tuning boost (2 byte load) for 93 OCT and was very close to where it wants to be.... (Used it to set the BDEL)...
Um, 27psi on stock turbo/stock cams is not 280 load... at least not the 2 Byte that most people log.
I spike 24psi and ~280 load, I hold above 270 load until about 5000RPM when it tapers... ~230 load at redline.
People running high octane and/or meth will run 27-28 psi at be over 300 load
I spike 24psi and ~280 load, I hold above 270 load until about 5000RPM when it tapers... ~230 load at redline.
People running high octane and/or meth will run 27-28 psi at be over 300 load
I am not sure what turbo you are using but hitting 27 PSI in 5K would be difficult. I would just set 100% MWGDC and see if it can hit it (I would also put 280ish all over the BDEL for testing purpose -- 280 - BOffset = number you want to set in BDEL)... That would be the max any way. Before you try it, make sure to put correction in so that it reduce WGDC if it does go up beyond your target...
Evolving Member
Joined: May 2007
Posts: 178
Likes: 0
From: Italy
Um, 27psi on stock turbo/stock cams is not 280 load... at least not the 2 Byte that most people log.
I spike 24psi and ~280 load, I hold above 270 load until about 5000RPM when it tapers... ~230 load at redline.
People running high octane and/or meth will run 27-28 psi at be over 300 load
I spike 24psi and ~280 load, I hold above 270 load until about 5000RPM when it tapers... ~230 load at redline.
People running high octane and/or meth will run 27-28 psi at be over 300 load
I'd suggest a couple things... first, a JDM MAP sensor. This will allow precise boost logging, as well as give you the option to use mrfred's true EBC (ie., you dial in a boost level and the JDM MAP reports back to ECU)
Using pump gas only, 26psi is pushing it... I was able to spike 26-27psi on pump with no knock, but honestly I'd rather not run more than 25psi on stock internals with only pump gas.