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-   -   max boost (https://www.rx7club.com/single-turbo-rx-7s-23/max-boost-627187/)

Feelin' Fine 02-25-07 02:50 PM

max boost
 
how much boost would be possible on a stock 93 with a gt35-40 turbo kit and methy inj. on pump gas? also does anyone know how much boost a rotary engine can handle?

fastcarfreak 02-25-07 04:22 PM

just pump: ~17-18 psi with good tune

pump and meth inj: ~24 psi i believe people are doing

fastcarfreak 02-25-07 04:24 PM

Rotary engines can pretty much handle as much boost as you can throw at them if you are dowel pinned, your clearances are good, the type of fuel your using is proper, and your tuned very good....

BLitzed33 02-25-07 04:40 PM


Originally Posted by fastcarfreak
just pump: ~17-18 psi with good tune

pump and meth inj: ~24 psi i believe people are doing

But make sure he realizes that if the meth system fails, he is done, because the tune will be tailored to the meth injection and if it fails, you will go lean and bad things will happen. I have seen most go to around 20-21 lbs on water/meth injection, but remember its not a bandaide for poor tuning or wanting to make a gazillion hp on pump. I myself wouldnt go above 16 on pump gas, just because you never know the consitency of the gas you are getting, or if you get a bad tank of gas or something like that. I actually dont run pump for that reason because I dont trust it, I just run race gas all the time, but of course mine isnt a daily driver and I want more power then what pump can provide.

I believe you are more limited to the power you make vs the boost you run, because I can make 562 whp at 27 lbs, while a guy can make 562 at 23 lbs with a bigger turbo pushing more volume for the same given boost, plus tuning and porting comes into play as well.

At a certain point you have to clearance your rotors to prevent rotor to housing contact. Dowl pinning is something people say you need, others say you dont.

GoodfellaFD3S 02-25-07 08:39 PM

On straight pump 93 octane, I wouldnt go above 15 psi. You need to leave a bit of a window, and in this case if you spike/creep to 16-17 psi under certain circumstances you'll be fine. With my water injection setup I run 17 psi on pump gas, which is plenty fast enough for the street.

pwwatkins 02-25-07 11:26 PM


Originally Posted by GoodfellaFD3S
On straight pump 93 octane, I wouldnt go above 15 psi. You need to leave a bit of a window, and in this case if you spike/creep to 16-17 psi under certain circumstances you'll be fine. With my water injection setup I run 17 psi on pump gas, which is plenty fast enough for the street.

Aren't you still gonna go with meth inj and up your boost to 24psi?

GoodfellaFD3S 02-25-07 11:29 PM


Originally Posted by pwwatkins
Aren't you still gonna go with meth inj and up your boost to 24psi?

At this point I'll be happy when I next get to drive the car (snowing like a mofo outside right now).

I may just run c16 for the higher boost, I recently found a convenient local source for it, and the FD is a weekend car at this point.

pwwatkins 02-25-07 11:40 PM

What made you change your mind? Why not c16 and meth

fastcarfreak 02-26-07 02:28 AM

thats why you run water injection and c16... then run as much boost as your fuel system can handle...

GoodfellaFD3S 02-26-07 08:19 AM


Originally Posted by fastcarfreak
thats why you run water injection and c16... then run as much boost as your fuel system can handle...

That's one thing I have to get sorted out. Supposedly there is an internal valve in my Apexi BNR33 pump that diverts fuel pressure above 75 psi, which approx correlates with 20 psi boost pressure. It's a great pump up until that point, but it looks like I may have to change up my fuel system, again.

mirabile 02-26-07 08:55 AM

Rich, can you post a few pictures of your water injection set up? If you have, I can not find them amongst your 15000000000 posts

fastcarfreak 02-26-07 12:31 PM


Originally Posted by GoodfellaFD3S
That's one thing I have to get sorted out. Supposedly there is an internal valve in my Apexi BNR33 pump that diverts fuel pressure above 75 psi, which approx correlates with 20 psi boost pressure. It's a great pump up until that point, but it looks like I may have to change up my fuel system, again.

are you saying your running 55 psi fuel pressure during normal driving? that is nuts...lol...unless im looking at this in the wrong way...

dont feel bad about redoing your fuel system... Im in the same boat as you are...Im throwing the Aeromotive a1000 in this year and redoing all the lines with SS braided.

tdazmansFD 02-26-07 04:38 PM

Other things to consider than the above are the turbo's efficiancy at particular boost levels. No use in running more pressure than the turbo is capable of right?
According to my compressor map, my max effiency is about 20-22lbs. 62-1.

GoodfellaFD3S 02-26-07 05:52 PM


Originally Posted by fastcarfreak
are you saying your running 55 psi fuel pressure during normal driving? that is nuts...lol...unless im looking at this in the wrong way...

dont feel bad about redoing your fuel system... Im in the same boat as you are...Im throwing the Aeromotive a1000 in this year and redoing all the lines with SS braided.

There is an approx 15 psi pressure drop through the fuel system, so base fuel pressure of 40 psi + 15 psi is where the 55 came from.

Some good reading here, this is back on the BNRs when I intended to keep boost levels below 20 psi:

https://www.rx7club.com/3rd-gen-archives-73/some-fuel-system-ramblings-578521/

GoodfellaFD3S 02-26-07 05:58 PM


Originally Posted by mirabile
Rich, can you post a few pictures of your water injection set up? If you have, I can not find them amongst your 15000000000 posts

A simple search for 'aquamist install' with my username and 'threads started by user' will give you the thread you want. Stangely enough, it's the first thread that comes up for the search results ;). The pics are on page three.


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