[Boost Me]

I’ve searched and can’t find a definitive answer to my question so I’ll post it to the group. I just upgraded my ’93 TT 6-speed Supra to full BPU. I installed the new Blitz SBC-ID III EBC and I’m a little fuzzy on the correct settings for my BPU setup. I would like to program a safe street driving setting (~12-13 PSI - with 93 octane gas), a performance/street setting (~16-18 PSI - with 93 octane gas) and a race/dyno set up (~21-22 PSI - with race gas).

Here are my mods in case you are wondering:
1.) MVP Max Air Intake System
2.) Apex’i Twin Chamber BOV – Came with the car when I bought it.
3.) RMM 3” Turbo Down Pipe
4.) HKS Super Dragger Exhaust
5.) Waste Gate Spring Mod
6.) Greddy BCC – set to 14.28 V per MKIV directions
7.) Powerhouse Racing EGR Block Off Plates – Waiting to be installed.
8.) Autometer Phantom Electric Full Sweep Boost Gauge
9.) Autometer Phantom Electric EGT Gauge

Thanks!

 

[MyKarIsVicious]

i get 14 psi with the controller off, so i dont think you will obtain 12-13

33% is 15psi for me
45% is 17-18 psi
55% and above would be 19-20 psi

but its a little different for all cars so just start at your lowest setting, put some race gas in and dial in ur settings

 

[VeilsideTT]

Yup, every car is very different. I saw 18-19 psi with my EBC off and saw no spikes with the gain at 100%. Others see very low boost with high settings. Just start low and keep turning it up until you get yor desired boost level. Keep in mind this may have to be adjusted for weather changes. Next, just crank the gain up until you see small spikes, then back it down a little.

 

[Nick 95 6sp]

I have it too, same advice as above.

 

[Hands On]

gain=15
Set ratio:
48=14psi
78=17psi
90=21psi
You will find that it is a guessing game. In different gears you will see different psi due to load conditions and ambient air temps. Just remember that the ratio is a percentage of your turbo's total capable output. So theoretically if your turbo can push 24psi max (not efficent of course) at set point of 100 you should see 24psi. Again all relative.

The best feature of the controller is the limiter warning function. Set it to your safe zone and then you don't have to worry about over boosting. It will actually let you pic a psi setting. I get so frustrated at guessing my boost level when dynoing and racing I want to play around with setting my limiter at the desired psi and put the controller to 100 and rely on the limiter. Hope it doesn't fail. To be cont....

P.s. I still haven't figured out how to turn it off.

 

[Nick 95 6sp]

If I recall correctly, I thought the instructions specifically recommend against using the "limiter" function to "control" the max boost, maybe it even explained why. If you work with other types of programmable controllers, PLC's etc, which I do sometimes, they typically operate in a very similar manner. I'm not saying don't try it, play to your hearts content. But using the high or low limit function of any controller is usually not a good way to control the process.

 

[ChBrAc16]

i have my SET at 60 and consistently hit 17-18psi with the gain set low, i cant remember but its between 8-10. i havent tried any higher b/c i want to control the spiking but i have the limiter set at 18.5 which is a great feature to have i think. with it off, like everyone else, i hit stock bpu boost of 14psi. to reiterate everyone else again, start low, i say at 50 and work yourself up from there. to calculate a dyno set up, the best bet is to make sure you put some race gas in the car and go cruising. find a nice highway and just keep doing pulls but make sure you have someone else in the car with you that can keep an eye out on the controller while u watch the road

 

[John H]

Yup, every car is very different. I saw 18-19 psi with my EBC off and saw no spikes with the gain at 100%. Others see very low boost with high settings. Just start low and keep turning it up until you get yor desired boost level. Keep in mind this may have to be adjusted for weather changes. Next, just crank the gain up until you see small spikes, then back it down a little.

I have the DSBC model, but maybe my question is applicable here.

WHAT does GAIN actually do? Is this the responsiveness of the actuators? Does a higher gain number coorelate to boost coming on quicker? Too high possibly causing boost spikes? I haven't experimented with the GAIN in a long time and I probably should. On stock turbos in sequential I recall having too high of gain would make a boost spike on the sequential transaction. I don't believe this is an issue with TTC or a single turbo. Correct? So would 100% GAIN have any drawbacks if it didn't spike?


John H

 

[John H]

I have the DSBC model, but maybe my question is applicable here.

WHAT does GAIN actually do? Is this the responsiveness of the actuators? Does a higher gain number coorelate to boost coming on quicker? Too high possibly causing boost spikes? I haven't experimented with the GAIN in a long time and I probably should. On stock turbos in sequential I recall having too high of gain would make a boost spike on the sequential transaction. I don't believe this is an issue with TTC or a single turbo. Correct? So would 100% GAIN have any drawbacks if it didn't spike?


John H

?????????????

 

[Espeefan]

I have the DSBC model, but maybe my question is applicable here.

WHAT does GAIN actually do? Is this the responsiveness of the actuators? Does a higher gain number coorelate to boost coming on quicker? Too high possibly causing boost spikes? I haven't experimented with the GAIN in a long time and I probably should. On stock turbos in sequential I recall having too high of gain would make a boost spike on the sequential transaction. I don't believe this is an issue with TTC or a single turbo. Correct? So would 100% GAIN have any drawbacks if it didn't spike?


John H

I'm still new to all of this EBC stuff too, as I just bought my Supra with a Blitz DSBC II already installed. From my reading and searching on the net for some kind of instruction as to the set-up of a boost controller like this, yes, gain controls how quick the boost comes on. Higher gain settings get the turbos spooling up quicker, but to high of a setting can cause over boost situations due to the solenoids not being able to react quick enough to open a wastegate once the limiter is hit.

I can't speak from experience yet, but it would seem that true twin set-ups and single turbos could also suffer over boost or spiking, but it seems to be related mainly to the size of your turbocharger. A bigger turbo won't spool as quick so a higher gain setting can be safely used.

Anyway, perhaps the best information I've found on setting up the Blitz DSBC was a link from mkiv.com.

http://www.geocities.com/MotorCity/Speedway/9589/dsbc_manual.html

This guy should be commended for a nice write up, especially since I didn't get a manual with my car for the boost controller. I'm still waiting to actually start playing with the boost controller and see what kind of tuning difference I can make. I've yet to even drive the car, so we'll see.

In the mean time, what settings would you guys recommend for the DSBC on a Supra with a full 3" exhaust, 3" down pipe, and a Greedy front mount IC? Also, where about does the computer shut off the fuel?

 

[VeilsideTT]

In the mean time, what settings would you guys recommend for the DSBC on a Supra with a full 3" exhaust, 3" down pipe, and a Greedy front mount IC? Also, where about does the computer shut off the fuel?

Again, theres no "right" setting or even anything that someone could recommend. Each car is very different and you need to figure it out for yourself. Start low and work your way up with the set. The gain setting should be done the same way.

Also, not sure what you mean by shut off fuel. if your talking about boost cut, I think its around 14psi. just get a BCC and you should be good to go.