Boost Spike

[PMJ]

Originally Posted by JANNETTYRACING

Must have been the 3 bad ones i sent back LOL

TPIS is Great to work with they helped Us quite a bit and provided us with Great customer service, and replaced all the units we had problems with.

All the ones we have out there now work well.

Moving One to the OP problem.

I believe what you need is to Tune the Predicted and VE Coefficient Tables and set them up for a 3 Bar Map as they are only set up for a 1 bar.

The Coefficient tables will fill in the void of the time between when the Throttle snaps open and the MAF actually sees the Air flow.

The Coefficient tables will provide the fuel based on TP RPM Air Temp and MAP without any input from the MAF..

I have seen this on Every Whipple Car we built, Until I did the Proper Tuning and All Gone.

Greg Banish Teaches this Technique in his Advanced Tuning Class.

You still Keep your MAF and Closed Loop and Enjoy all the Benefits without Disabling Anything.


Ted.

Thank you Ted! I will definitely take this to my tuner. I'm curious why Whipple isn't aware of this issue? Maybe the 3 bar map isn't that common.

Pat

[JANNETTYRACING]

Originally Posted by PMJ

Thank you Ted! I will definitely take this to my tuner. I'm curious why Whipple isn't aware of this issue? Maybe the 3 bar map isn't that common.

Pat

Your Welcome, He will need a copy of HPtuners and the Blue Cat tool or EFI Live to create a virtual VE.

There is No fuel in the Coefficient tables above 1.2 Bar so you have to carry that out and fine tune it when adding a 3 bar MAP

The distance between the MAF and the intake valve is Longer with a Whipple, and there is a lot more (What we Call) Plenum Volume because of it's size.

So the Motor takes a gulp of Air with NO Fuel to Cover the HOLE before the MAF Sees it.

The Further the MAF is from the intake valve the worse this problem gets.

Remember Air flows Like a Slinky.

[ToddB]

BBK has some new throttle body's coming out. Hope they work cause I want a 102 for my whipple.

[Supercharged SS]

Originally Posted by ToddB

BBK has some new throttle body's coming out. Hope they work cause I want a 102 for my whipple.

You can get a TPIS 102 right now.

[Whipped416]

TPIS

[ayousef]

Originally Posted by JANNETTYRACING

Your Welcome, He will need a copy of HPtuners and the Blue Cat tool or EFI Live to create a virtual VE.

There is No fuel in the Coefficient tables above 1.2 Bar so you have to carry that out and fine tune it when adding a 3 bar MAP

The distance between the MAF and the intake valve is Longer with a Whipple, and there is a lot more (What we Call) Plenum Volume because of it's size.

So the Motor takes a gulp of Air with NO Fuel to Cover the HOLE before the MAF Sees it.

The Further the MAF is from the intake valve the worse this problem gets.

Remember Air flows Like a Slinky.

So Ted, what you suggested might be a plausible explain ion for the Lean spot hes getting, but what explains the boost spike, as far as I know the MAP values we read are simply lookup values for the voltage using the inputed 0-5v MAP voltage slope.

So im thinking your idea could solve the Lean AFR which is a symptom associated with the spike, but not solve the original problem, which is the boost spike.

[JANNETTYRACING]

The boost spike is a product of the rotor speed and how fast the bypass valve closes

[JANNETTYRACING]

The fix is in shifting with the throttle on the floor Or what is better known as power shifting

[JANNETTYRACING]

This would prevent the bypass valve from opening between shifts

[mikepage0007]

on the tpis , i had issues with the tpis throwing code on decel around the 3k rpm...would go into protect mode...of course , that happens to be my highway cruising speed around 80-85mph, if i would see a cop, i would let off gas and it would throw code...jim sent another tb and it worked perfect...as for the big hp gains, we had to tune the car on the stock tb, and when we got tpis in we retuned and only saw about a 8hp gain...imo..

[PMJ]

I'm at the track now. I'll try that in my next run. Always scares me.

[ayousef]

Originally Posted by JANNETTYRACING

The boost spike is a product of the rotor speed and how fast the bypass valve closes

rotor speed is always in sync with crank speed so there is no way the rotor is spinning out of sync causing the boost spike.

What im saying is if at 4000rpms the blower is spinning at 8000rpms (just for the sake of the argument) it should compress enough air to pressurize the manifold 5psi, there is no way the blower is spinning 16,000rpms at 4000rpm engine speed to cause such a HUGE boost spike.

plus if you look at one of his logs the boost was spiking DURING the run.

[ayousef]

Originally Posted by JANNETTYRACING

This would prevent the bypass valve from opening between shifts

the bypass valve IS opening between shifts and is very obvious in the printscreens on the first page, notice how MAP drops to a very low value and then jumps and keeps on going up.

I did find that desired throttle position isn't equal to actual throttle position, and ive seen this exact phenomena cause spike even though I dont know how to explain it well, im thinking the throttle body opens up flows alot of air gets to the point where it cannot hold blade position due to the large amount of CFM flowing through the motor shuts partially and causes a spike of pressurized air between the throttle and the cylinders on a decelerating motor, notice how the spikes are happening when the throttlebody is OPEN but rpms are steady or in some cases going down.

This is just a theory.

[PMJ]

Originally Posted by mikepage0007

on the tpis , i had issues with the tpis throwing code on decel around the 3k rpm...would go into protect mode...of course , that happens to be my highway cruising speed around 80-85mph, if i would see a cop, i would let off gas and it would throw code...jim sent another tb and it worked perfect...as for the big hp gains, we had to tune the car on the stock tb, and when we got tpis in we retuned and only saw about a 8hp gain...imo..

How much boost are you making? Was your stock TB a bottleneck? Whipple says my TB is a bottleneck...i should be making 16+ psi, but only making 15. So if the TPiS lets the air flow, i should get another pound out of it...which should be good for 20+ hp easy. At least that's the theory.

I'm also seeing ridiculous IATs, my coolest run at the track tonight got up to 172 degrees (hotest was 199) ; Ted posted he saw a 25 degree drop in IATs...I'm thinking that and the RX Super CHiller i have ordered should knock out my IAT issue.

I have some work to do, but I'm determined to get into the 10s my next trip to the track.