LPM programming?

[jmpSHO]

I didn't get any responses so I guess I will change my question. Will I benefit any by changing when my secondaries open? I was thinking that if they open up a little early it might benefit me a little maybe at like 3800rpm as opposed to stock 3950.

 

[jmpSHO]

By the way my SHO is a 95 ATX with a CAI, highflow cats (I might try catless though) and Magnaflow mufflers and I will be adding an 80mm Mark VIII MAF.

 

[VortecGT]

I dont really know but yamaha did put a lot of thought into the intake. I really dont think it will gain any power but you will get to hear them open up more often!!!

 

[hawkeye18]

There is really only one good way to figure out when you need to open your secondaries.

You need to do two dyno runs. on the first one, you need to force the secondaries closed. Do do this, disconnect the secondaries controller electrically, or use any other method to ensure that vacuum is constantly applied to the secondaries.

Then, you need to make another run with them forced open. To do this, you need to simply disconnect the vacuum reservoir for the secondaries and cap the vacuum ****** at the intake. Or any other method of preventing vacuum from reaching the secondaries.

Then, compare the charts for the two runs. Where the HP lines cross on the two charts is when you need to open your secondaries.

It may very well not be at 3950 RPM, which is the factory setpoint. It might be earlier, it might be later, but you won't know unless you have those charts to compare.

 

[Lupo]

There is really only one good way to figure out when you need to open your secondaries.

You need to do two dyno runs. on the first one, you need to force the secondaries closed. Do do this, disconnect the secondaries controller electrically, or use any other method to ensure that vacuum is constantly applied to the secondaries.

Then, you need to make another run with them forced open. To do this, you need to simply disconnect the vacuum reservoir for the secondaries and cap the vacuum ****** at the intake. Or any other method of preventing vacuum from reaching the secondaries.

Then, compare the charts for the two runs. Where the HP lines cross on the two charts is when you need to open your secondaries.

It may very well not be at 3950 RPM, which is the factory setpoint. It might be earlier, it might be later, but you won't know unless you have those charts to compare.

Exactly!

Funny enough, in F/I setups, the optimum RPM to open the secondaries in much higher than stock.

 

[walser]

when i got mine tuned, i set it at 3800 rpm secondary opening and the guy programming it at shosource told me i would gain nothing, just loose some torque... and id imagine they know exactly what there talking about. so of course i listened. for my mods look in my sig

 

[jmpSHO]

Thanks for the response because that was what I was going to set mine at.

 

[jmpSHO]

when i got mine tuned, i set it at 3800 rpm secondary opening and the guy programming it at shosource told me i would gain nothing, just loose some torque... and id imagine they know exactly what there talking about. so of course i listened. for my mods look in my sig

How do like the y pipe without cats?

 

[walser]

well my y pipe is a stock with a sho source tail end. its virtually a stock y pipe without cats but the actual Y part is from shosource. and i have a set of high flow cats im thinking about putting them on. the only difference I felt with the new Y without cats was it was raspier and much louder with a little bit more low end torque... im working on finding a real y pipe used for cheap. the idiot i bought it from decided to cut the damn thing in half. i was not happy lol