Hi,

I read here on H-T a while ago about disconnecting some vacuum tube to make the secondaries open all the time. I've done a search in the archives but I think they were lost. I know it decreases all the low end torque and some people noted that the top-end didn't improve much either, but will the 1-2 gear shift be better?

I haven't done much racing in my GSR (new timing belt needed) since I got it, but I heard that when the GSR shifts from 1 to 2 gear, it drops out of the secondaries.

My question is, will opening the secondaries all the time net me better times if 2nd gear doesn't fall out of the secondary range? or am I all wrong about the 1-2 shift?

Thanks

 

disconnecting the secondaries wont give you any gains. better to just leave them there and get a skunk manifold if ya want to get rid of them.

you are right about the 1-2 shifts

 

disconecting the secondaries is stupid on a a stock gsr u will lose bottom end and gain absolutely nothing up top dont do it

 

Thanks for all the info, I guess i'll be keeping this manifold until I get some cams or something else that requires lots of air.

Thanks

 

my secondaries stay open when I shift from 1-2.

 

Mine too.

 

a short shifter doesnt help??

 

i drop outa my secondary. do you power shift or something to stay in it???

 

What RPM does it fall when you shift 1st gear at 8200rpm? I dont pay attention. LMK-

 

yes, i'd also like to know. does the secondaries come open at 5800rpm? correct me if I am wrong. Thanks

 

The GSR secondary runners in the intake mani are supposed to open up at 5800 rpm. I've never checked how far RPMs drop from 8k rpm when shifting from 1st to 2nd 'cause I'm always looking at the road. But I'm guessing a good 1-2 shift will keep you close to 5800-6k rpm, maybe 5500 rpm at the lowest. So, even if you drop below 5800, it won't be for very long. You'll be whistlin' 'Dixie' in no time.

 

Mine close too, just briefly, and only in the 1 - 2 shift. Short of changing your gearing, or changing when the vacuum diaphram...

 

No powershifting. Just shift at redline. Just shift fast. Remember, fast doesn't mean hard/abusive.

If your shifting slower than an automatic, that's too slow.

 

ever since i put my rims on, my secondaries close, bnut only for a brief second. the rpms fall to about 5600 according to my VAFC. on my stockie rims tho , it doesnt happen

 

Don't pull the hose to the diaphram connected to the secondaries. I did this and my car went into limp mode. To get out of limp mode i had to pull a fuse(can't remember wich one).

 

the rpm's drop 2500 from 1 to 2 gear so if you shift at 8100 rpm, you will land around 5600 rpm in 2 gear. Secondaries open at 5750 rpm.
If if shifting "fast" the rpm's will still drop 2500 from 1 to 2 gear. That's beacuse of gear ratios, not how "fast" you shift so if you take "forever" to shift the rpms will still drop by the same amount.

 

This man is correct, I owe you a beer if you're ever in Houston.

I guess I never paid attention to the 1-2 shift or am always focused on the 2-3 shift. Either way, I was wrong. I made an effort tonight to pay attention and yup, it does fall out of secondaries for a brief moment.

Hey, I can admit I'm wrong.

 

So what happens if you make the secondaries open all the time? Will it improve your time since you don't fall out of the range from the 1-2 shift?
I know that on the new Celica GT-S's, if you fall outta VVTi on the 1-2 shift, you're 1/4 miles times drop bad.

 

It'll hurt daily driveability as low end will suffer. Secondaries are tuned to open up and help extend the torque curve starting at a certain rpm. Open them too early and the power will drop. Rigging them to stay open won't help either for racing.

The Celica's problem isn't the VVTi rpm crossover, but the gearing.

 

You can't really compare a gsr's secondaries to a gts's lift(VVTL-i). A gsr has a much smoother powerband whereas the gts is nothing below 6k no low end at all. It get a major boost in hp once you hit 6k though. Sucks to be a 02 gts, they're rev limit is 7700, while the 00,01 have a 8300 limit.

 

do not leave the runners open all the time because your car will feel VERY VERY slow. Honda R&D Engineers already spent many hours on this. Just leave the IM alone, unless you have many mods including a higher redline.

Jesse H, I was in Houston last weekend. I am from Sugarland also.

BTW, from 2 to 3 gear the rpm's drop by 2000 that's why from 2 to 3 gear the runners stay open. I hated 2nd gear in the GSR. It seemed very long.


[Modified by 1fastGSR, 9:27 AM 4/6/2002]

 

thanks for all the replies, it helped me alot, I guess you guys satisfied my curiousity. BTW, I love the 2nd gear, its short, but since we redline high it seems long. It always seems to help me pull away from my opponents, especially third gear.

 

The reason you drop the secondaries in the first place is because of the "60mph conspiracy." Anyone remember that from SCC, or SS, some import mag. Basically, because most automotive magazines test 0-60mph times and it is a pretty standard benchmark, the 2-3 shift always occurs after 60mph. Anything from a little '91 Corolla, to an '03 Lancer Evo. They tested a lot of cars. They set up the 2nd gear ratio badly. A good "racing" gearbox would keep the car in the powerband all the time. HTH...just shedding some light...

-Andrew

 

Just for information, how would I enable the secondaries to be open all the time?

 

pull the vaccum hose from the tank under the manifold.