would it have to be a specific BOV? how about a wastegate. can that be used? also, im interested in knowing how it would be implemented to prevent surging at lower rpms.

thanks

 

I won't post name brands, but yes, you would want to use a BOV that is setup similar to a wastegate, or use a wastegate. The strategy that I'm using requires pressure control chambers above and below the diaphragm.
The BOV can be controlled to open easily with small boost numbers which would keep you away from the surge line. You would need to incorporate some simple electronic controls to come up with a control strategy that would work bitchin for what you're trying to accomplish.

 

I know JGS made theirs with two nipples for that reason.

 

Yeah, I'm trying to spin two mp t70s with a 5.3 on e85. The calculator says its doable but a blowoff strategy might be necesary if for some reason I can't get out of surge.

Will a bov strategy allow measured bleeding or will it open and let all the air escape because my goal is to be able to tune it so that if the 5.3 can only use x amount of air at say 3500rpms then it will get exactly that amount.

Do you think this is possible?

 

It is very do-able. CO2 control would be the easiest way to accomplish this. Although, you could play with varying springs or spring setting adjustments to accomplish the same.
What I've found with my system is that a 1 psi change in CO2 control pressure to the BOV nets very close to a 1 psi change in boost level. It is extremely controllable.

 

great to know thanks. I think if I need it I will try it with an inexpensive wastegate.

 

The latest high boost launch with the car. The creep feature is pretty well dialed in. The tires didn't do too good at this power level. The MAP was between 260-277 kPa for this launch. Notice how quickly the turbo came up on boost.

 

What was the time?

 

On that run, you can see that the car snaked at the start. The car never really straightened out the rest of the run and I was forced to get out of it before the finish line. You can hear the tires squeal on the top end at the end of the video. It was starting to get a little hairy. Still, the car clocked off a 1.323 60', 5.79 et @ 110.19 mph. Down 16 mph at the finish.

 

I like how it's not a 2min vid to watch a 1/8 mile run

 

Is that the creep feature on the FAST ?

Doesnt seem any different than just bumping the t-brake button .

 

No. It's my own creation.
It's different. Much more controllable and less harsh.

Finally got a 1/4 mile time on a real pro light at the Pinks event in Arizona yesterday and today.
1.339 60', 8.769 @ 156.81. Highest mph for the day was 158.69.
I was expecting 8.90s. 8.80s was a far fetched dream.
The staging creep was flawless and automatic.

 

Guess it wasn't that far fetched of a dream huh? Congrats on the .76!!!! Theres enough mph there for a .6x too!

 

Uh oh. Time for cage work. Get ready....
Congrats Donnie. Wish I coulda seen your face man.

 

With these quarter passes, the engine showed me that it is absolutely craving more fuel. I'll be throwing a 4 bar map sensor on it and mounting a mechanical fuel pump.

During the event I had to lower the nitrous turn off point, lower the launch rpm/boost level, and raise the wheelie bars to get traction at the start. Very poor launching pad for my needs. Still, I was able to crank out a 1.33 on a pro light. And, this light came down quick. I was very happy with the way the ALS and the staging creep worked. I actually had to tune down the launch because too much power was being built up by launch time. I never would have thought that was going to be a problem with my configuration. This engine absolutely amazes me.

I think there's 8.50s in this car,... but then, this car always likes to surprise me. 8)

 

Who would ever have thought that heads with 1.835 intake valves and 1.500 exhaust valves on a small V6 could perform like this. Heck, when I first put this motor together, I thought I'd be lucky to break into the high nines, let alone trying to surpass my chassis cert. Holy cow!

Can you guys tell I'm stoked?

 

I've been following this thread from the start and I gotta say, it's awesome to see how well it's working. Congrats.

 

Thanks for the congrats. It's all very much appreciated. I've got some video of 3 of the 4 passes. I'll do some editing and get it posted up soon.

You won't believe how quick this 91mm spooled. Amazing.

 

Here's the video of the 8.76 run at Pinks All Out. This was the last qualifying run (arm drop start). Doesn't look like much. Hard to believe it's an 8 sec run.
If you listen hard to the video, you'll hear the engine lean surging at the 1,000' mark. The engine was leaning dangerously due to a borderline fuel supply system. That will be addressed. Over the weekend, I tried to throw more fuel at the top end, but that just made more power and boost, which just increased the demand for more fuel.
There's more in her, people.

The car in the other lane got a 3 tenths jump on me. I was sleeping. Beat me at the end by one tenth. If only I had a better reaction time, it would have turned out to be a close race.

Check out how quick I got that 91mm to speed. I didn't go WOT until after final staging.
Due to track conditions, I actually had to de-tune the launch to get the car to hook. On the two previous runs, the tires went up in smoke at the launch.

 

New bests for the car. 5.57 @ 126 mph in the 1/8 mile. 1.27 60'.
Time on the system before launching, 1.76 seconds.