Surging

[1LeSS]

So I have big surging when holding a high rpm. And I have surging in alot of the drivability area too.
6.2ltr, V3si tuner kit, 8.3 lb boost. What's the general conscientious say out there? Bigger blowoff valve..
Ask me questions. Gotta figure this out.

[1fast]

Originally Posted by 1LeSS

So I have big surging when holding a high rpm. And I have surging in alot of the drivability area too.
6.2ltr, V3si tuner kit, 8.3 lb boost. What's the general conscientious say out there? Bigger blowoff valve..
Ask me questions. Gotta figure this out.

When you say high rpm what is high ? and surging on normal driving tend to be fueling issue. A log file would help,

[1KillerSS]

Originally Posted by 1fast

When you say high rpm what is high ? and surging on normal driving tend to be fueling issue. A log file would help,

Could tell a lot with a good data log.

[JANNETTYRACING]

Originally Posted by 1LeSS

So I have big surging when holding a high rpm. And I have surging in alot of the drivability area too.
6.2ltr, V3si tuner kit, 8.3 lb boost. What's the general conscientious say out there? Bigger blowoff valve..
Ask me questions. Gotta figure this out.

What tune are you running?

What injectors?

What fuel pump?

We typically add a second by pass valve on the same pipe to double the bypass.

Ted.

[1LeSS]

the surging happens mostly during autocross. Say I stay in first gear between cones and i'm holding 4500rpm, just as i'm about to enter the next corner, the engine will surge and almost push me out of the corner. the higher the rpm, the more violent the surge. it will surge even at 3000rpm, just not as violent.
zl1 fuel pump
custom tune
63lb/hr Siemens HighZ injectors.

no data log cause the car is now parked ��

The installers are saying I need a bigger BOV. I'm running the Vortech V3si with a maxflow BOV. Vortech says that BOV is good for 1300hp, (which I do not have)

[Unreal]

That BOV is more than enough for anything that blower can move IMO.

I would say tune would be first thing to look at.

Also swap to SD if possibly, works so much better for stuff like this.

[Ajdin@A2BMotorsport]

Originally Posted by Unreal

That BOV is more than enough for anything that blower can move IMO.

I would say tune would be first thing to look at.

Also swap to SD if possibly, works so much better for stuff like this.

Like Unreal said you dont need another BOV that Vortech Maxflow is more than enough, if you can get the datalog, send it over to me and ill have Arun take a look at it.

[vortechc5@A2B Motorsport]

Originally Posted by Unreal

That BOV is more than enough for anything that blower can move IMO.

I would say tune would be first thing to look at.

Also swap to SD if possibly, works so much better for stuff like this.

I agree with Unreal. Not sure if SD would help since the BOV is so far way from the MAF.

[JANNETTYRACING]

Originally Posted by 1LeSS

the surging happens mostly during autocross. Say I stay in first gear between cones and i'm holding 4500rpm, just as i'm about to enter the next corner, the engine will surge and almost push me out of the corner. the higher the rpm, the more violent the surge. it will surge even at 3000rpm, just not as violent.
zl1 fuel pump
custom tune
63lb/hr Siemens HighZ injectors.

no data log cause the car is now parked ��

The installers are saying I need a bigger BOV. I'm running the Vortech V3si with a maxflow BOV. Vortech says that BOV is good for 1300hp, (which I do not have)

You do need another bypass this will correct you problem seen it with these kits quite a few times.

The little 38 mm bypass is barely enough for 500 HP so I don't know who you talked to, but 1300 hp is not even in the ball park.

At 4500 RPM in a road coarse situation that blower is moving a lot of air and has no where to go with your throttle open slightly.

Air stacks up and rebounds like a Slinky in the cold pipe.

At 4500 RPM the blower is moving the same amount of air whether your throttle is open or closed, it needs a place to go.

At 1300 HP we run 2, 50 mm bypasses on the hot pipe for drag racing and would not be enough for road racing conditions.

Ted.

[Trob85]

Originally Posted by JANNETTYRACING

You do need another bypass this will correct you problem seen it with these kits quite a few times.

The little 38 mm bypass is barely enough for 500 HP so I don't know who you talked to, but 1300 hp is not even in the ball park.

At 4500 RPM in a road coarse situation that blower is moving a lot of air and has no where to go with your throttle open slightly.

Air stacks up and rebounds like a Slinky in the cold pipe.

At 4500 RPM the blower is moving the same amount of air whether your throttle is open or closed, it needs a place to go.

At 1300 HP we run 2, 50 mm bypasses on the hot pipe for drag racing and would not be enough for road racing conditions.

Ted.

He's not running 1300 hp though.

[1LeSS]

Appreciating the input. Myself, I'm stuck between the tune and the extra BOV.
I can't get a datalog because we've hit snow now. Should something change I will definitely grab a datalog .
I suppose you just want me to drive the car and capture when it is surging?

Thanks again

Ps, what is SD?

[Slowhawk]

I would just dump the MAF, probably the route of the cause and go 2 or 3 bar SD.

[JANNETTYRACING]

Originally Posted by Trob85

He's not running 1300 hp though.

I didn't say he ways I was referencing what he was told by some one else that 1 38 mm bypass is good for 1300 HP which is laughable.

2 38 mm bypass valves will cure the problem no question about it.

This is not a new problem or a tune problem.

Ted.

[1LeSS]

Thanks Ted. As soon as we get out of hibernation, I'll be giving you a call.