Vacuum and altitude?

[Canuck]

How much lower is your vacuum from seal level. On my RX7 I am suppose to get about 16 in/Hg but here I only get about 11-12. Is this ok or is it too big of a drop considering altitude?

Thanks

[Skaterkid]

This why you had your hood open today? Rode by on my bike and saw you with the hood open. Woulda said hi, but I had to get to class.

[Canuck]

This why you had your hood open today? Rode by on my bike and saw you with the hood open. Woulda said hi, but I had to get to class.

Yep, just installed the boost gauge. I have some serious creep problems that I need to take care of asap with a boost controler.

[Skaterkid]

Yeah, creeps always a problem with those bad boys. Boost spikes too, but you don't seem to have much of a problem with that.

[Canuck]

Yeah, creeps always a problem with those bad boys. Boost spikes too, but you don't seem to have much of a problem with that.

No but creep seems to be a problem anytime it is less than 50 deg out. I can't imaginge how bad it would be at sea level.

[HONDA GHANDI]

You are correct canuck. The altitude will affect your low vacuum settings. The best you can hope for here is maybe 18-20 going 100mph down a hill with the throttle shut completly.

[stu]

I get 18 whenever I let off the throttle over like 30mph. Otherwise it's at 16.

[Canuck]

I get 18 whenever I let off the throttle over like 30mph. Otherwise it's at 16.

I get about 18 off the throttle to, but idle is only 12 when the car is warm.

So would this low vacuum do to altitude also affect how the sequential turbos work since they are actuated by vacuum?

[HONDA GHANDI]

No, they will actuate from full boost at about 8-10 inches. That is all thats needed to move the wastegates. Just make sure they have a dedicated vacuum source, no tees and extra accessories and stuff off the vac line. Same with the MAP sensor, it needs to have a dedicated vac source also.

[Canuck]

No, they will actuate from full boost at about 8-10 inches. That is all thats needed to move the wastegates. Just make sure they have a dedicated vacuum source, no tees and extra accessories and stuff off the vac line. Same with the MAP sensor, it needs to have a dedicated vac source also.

It nice to have an extra point off the maniflod to tap the boost gauge. The japanese version comes with a boost gauge so I didn't have to tap any vacuum lines.

[stu]

Same with the MAP sensor, it needs to have a dedicated vac source also.

Is this true for me as well? Right now I have the boost guage teed off the map sensor line. I didn't realize it until last night though.

[sqrsaab]

This why you had your hood open today? Rode by on my bike and saw you with the hood open. Woulda said hi, but I had to get to class.

You guys go to mines?

[Skaterkid]

Yeah, and we live in the same apartment complex

[ryanman]

In CO I'd get about 14-16 vac and when I'd come down here to TX I'd get about 19-21 depending on weather.

[s1ngle]

i bet i know which apartment, mines park?

[Canuck]

i bet i know which apartment, mines park?

Nope, and I don;t really want to say since I would prefer to keep my car :)

[Mario]

i bet i know which apartment, mines park?

Does it honestly matter...?
;NutKick;

[Canuck]

Does it honestly matter...?
;NutKick;

It does to the theives who read this thread!!!

[gjcivic]

but you don't have a honda...... no worrys for you

[Mario]

It does to the theives who read this thread!!!

Exactly. Just thought I'd realize that in public... :cool:

[Canuck]

but you don't have a honda...... no worrys for you

Lol true, true. :)

[hsunchen]

You are correct canuck. The altitude will affect your low vacuum settings. The best you can hope for here is maybe 18-20 going 100mph down a hill with the throttle shut completly.

It will vary based on what cam you're running also, and any cam gear tuning you've done. At least that's what appears to be the case with my limited experience.

You thread hijackers can continue with your off-topic BS now. :Peace:

[HONDA GHANDI]

Right, cam tuning and overlap will have a lot to do with it. On a stock engine though the numbers I put up are the norm. On a big block chrysler I worked on last year we were lucky to see 8 inches. The power brakes didnt even work any more. Good thing it was making 800 hp and we couldnt get it stopped.

[s1ngle]

It does to the theives who read this thread!!!

sorry, i didnt mean to reveal you. I think ive seen your car around!! is it the grey RX7 with the bling bling mufflers?

[Canuck]

sorry, i didnt mean to reveal you. I think ive seen your car around!! is it the grey RX7 with the bling bling mufflers?

Nope its white, and the exhaust isn't that bling bling.

[Skaterkid]

I still have a hard time believing the exhaust isn't stock

[Canuck]

I still have a hard time believing the exhaust isn't stock

I know racing beat makes such a nice, quite low key exhaust that flows so well!!!