LB Lex

As most of you know, there is a secondary "throttle" in the mid-section of the intake manifold. Some of us, including me, have experimented by holding the valve partially open. A 1/8 to 1/4 inch gap seemed to work the best, anymore didn't seem to help. I think that holding the valve open any more than 1/8 or 1/4 disrupts the air-flow too much, so it has a negative effect. And opening it all the way might reduce low-speed torque because there is too much air-flow. This was just a thought.

The other day, I was on SupraForums where one of the members described the valve as controlling air-flow into the two middle cylinders (3, 4) because he saw it when he took the intake manifold apart. Going on this knowledge, I used a zip-tie to hold the secondary "throttle" open all the time. I did this so the #3 & 4 cylinders are receiving more airflow during medium-speed acceleration, which would hopefully increase mid-speed torque.

Well, I tried it out for the last few days and it seems to have increased the "seat-of-the-pants" pull during low to medium acceleration. When I cruise on the freeway, I barely have to keep my foot on the throttle because it seems to be making more power now. And when I give it a little gas while going around 75-80, it seems to pick up speed faster.

Although this mod will not increase full-throttle (hard) acceleration because the valve opens all the way when flooring the gas pedal, it seems to be a nice power-boost. I will write more after a few more days.

LB Lex

Well, it's been four days now since I tried this little experiment I am pleased by it. I really like the increased mid-range power, which helps out during acceleration on the street and freeway. Like I said though, it doesn't help when you floor the gas pedal all the way because this secondary "throttle" opens during full-throttle acceleration anyways.

Since most of my acceleration is done when I push down the gas pedal half-way, this mod gives a noticeable boost in power because the 3 and 4 cylinders are getting more airflow during part-throttle acceleration. Not only that, the transmission doesn't have to downshift because of the added power during part-throttle acceleration, and I find this better than downshifting because it takes the tranny a second or two to downshift. And when it downshifts, the engine goes to around 4,500- 5,000 rpm, which leaves me 1,500 rpm of power before it hits redline. Since I don't have to downshift, the engine moves the car swiftly from 2,500 rpm and up, and therefore I still have a lot of useable RPMs before it hits redline.

Since doing this mod, I haven't noticed my gas mileage go down, so it seems like there is no down-side to it.

On another note, I have to find a way to keep the valve open all the time (right now I am using a zip-tie to hold it open). I will work on a solution this weekend.

Pianoman72

Thanks for posting up the info. Sounds like something we can all benefit from!

gompka

iTrader: (6)

Well I went ahead and tried this mod today, i kept the throttle open with a wire that I tied around the end of the throttle and a metal piece under the intake manifold, it holds nice and tight. I noticed a big improvement in acceleration, the car shifts much faster now when you give it some gas. Can't wait to try it on the highway tonight seems like the faster you go the better hehe.

LB Lex

I'm glad to hear that you like the mod and that it works well

Wald GS

iTrader: (1)

I have no clue what you guys are talking about. Can one of you take a pic and explain what to zip tie? Thanks
hehehe

LB Lex

Here ya go: (this photo is courtesy of CL member Marcus)

Wald GS

iTrader: (1)

Thanks Eric! I don't know if I should do this. I'm afraid I will mess something up.

LB Lex

All this mod does is allow air to flow into cylinder 3 & 4 during part-throttle acceleration. The worst it could do is slow down the car by letting in too much air, but it seems like our cars hunger for more more air.

Hey, you could easily undo this mod if you don't like it!

Wald GS

iTrader: (1)

After putting in my injen hi flow air filter I guess this may NOT effect me. I don't know..

gompka

iTrader: (6)

I dunno if its my lead foot driving style since I got the mod or the mod itself but i went through a tank of gas like a can of coke since I did the mod, I also have a cone intake. I'll drive normally this week and i'll see if it makes a difference. anyone else notice this?

LB Lex

The mod does in extra air, and if you have a lead foot more gas will be used. I don't have much of a lead foot, so my gas mileage has not drop off.

Pianoman72

here's my attempt at it. I couldn't get it all the way open but most of the way. The hood kept coming down on me and I couldn't find my vice grip.

I used picture hanging wire twisted together.

LB Lex

So how does it feel, any improvement?

Pianoman72

I think it has helped a little bit. Kind of more response from the engine when i give it some throttle. Need to do more driving. Do you think I got it open enough?