How can I boost more than 16 psi?
08-08-01, 02:00 PM
#1
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How can I boost more than 16 psi?
I have a 93 FD. T-88 kit, RP comp fuel pump, RP 1600 inj kit, Paxton fuel reg, FMIC, Apexi PFC, pulleys and all the little extra's. (pulleys, ast deletion,suspension stuff, etc..)
I'm still running 73K on the stock motor, but it still runs strong.
On 93 octane I was suggested to run no more than 15 psi. Is there any way I can boost up? (besides the 116 octane thing) There aren't too many places I can get that kind of octane. What mods can I do. Also a street port w/ bigger seals are on my to do list.
I want to KICK some mitsubishi Butt!!
I'm still running 73K on the stock motor, but it still runs strong.
On 93 octane I was suggested to run no more than 15 psi. Is there any way I can boost up? (besides the 116 octane thing) There aren't too many places I can get that kind of octane. What mods can I do. Also a street port w/ bigger seals are on my to do list.
I want to KICK some mitsubishi Butt!!
08-08-01, 06:06 PM
#2
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I'm no expert, I'm sure someone with more knowledge and hands on experience will speak up, but...
Either a second fuel pump to complement the one you've got, or one of the higher flowing/less plug-and-play pumps.
And better apex seals. My mechanic/tuner told me I'd really want 2 piece seals (we go back and forth on the 2mm/3mm issue) before running higher boost levels (and while the engine is apart for the seals, might as well port at the same time, though I don't think it's a requirement for higher boost).
Tuning is the other side of it, of course. And this is where I get confused. People say that with proper tuning, you can run as much boost as you want. So, ok, let's say my tuner (or me, with some more knowledge) starts tuning and he finds I can run 18psi with no problems and a nice margin for error. But then people also say you need better seals at more than 16psi. Ok, why? If I'm not detonating, why do I need the seals? And if I am detonating, better seals aren't going to solve the problem, I'm just going to wind up breaking them.
So what's up with the better seals? I know they help with the floating, issue, right? But the floating thing is mostly and RPM issue, isn't it? So, are 2 piece (or 1 piece) seals just better able to maintain the seal under high boost pressure or something?
Sorry. I didn't mean to try to answer a question, and then ask more questions, it just came out that way...
08-08-01, 06:07 PM
#3
NYC's Loudest FD
I was running 20psi in the street with 93 octane with a T88, stock seals and never had a problem with anything. From what I see that your car has, my only question is what size of primary injectors are you using? Cause that will be your limiting factor in how much boost you can run.
08-08-01, 06:36 PM
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I was going to run the 850 primaries and 1600 secondaries, although Dave at KD rotary talked me out of it. He's going to install the 550 - 1600 combo. He said it wouldn't make a difference, my car would actually run better with the 550's as the primaries. (something about running rich) Anyway, Ari at RX7.com told me he was always running the 550 - 1600 combo too. But he's got that horse power everyone would want, even without NOS. I still haven't had my question answered. I want at least 500 rwhp!!!
(streetable of course, how else will I be able to kick some mitsubishi ***?)
(streetable of course, how else will I be able to kick some mitsubishi ***?)
08-08-01, 07:31 PM
#6
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From the information I have gathered on this subject, it is my understanding that you can safely run up to 20psi on 93octane. Maybe you wouldn't want to go higher than 18psi, but I think as long as you are running 12:1 air/fuel and have the injector size you are plenty safe. What ecu are you running?
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08-12-01, 10:40 AM
#8
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I've been getting pm's from people that had the 850 - 1600 set up. They say their cars run well, and if for any reason they need the extra fuel, they have it. Besides Dave put that exact set up on AARotary's car, so why not mine? (I've got a larger turbo than he does)
08-12-01, 11:04 AM
#9
Bigger and better things
Usually a big port job and a big injectors is a problem... They have a harder time keeping the flow constant..
I would go with 550cc as primarys and 1200cc's as secondarys.. And if my seltup was crazy enough (t-100 ?) to warrant more fuel Id go with an AIC and run 850cc's there too!
That ensures good idel. Good midrange and great top end aswell as more tuneability than the PFC allows and keeps injector cycle duty low enough to never have an issue about a stuck open or overloaded injector!
I would go with 550cc as primarys and 1200cc's as secondarys.. And if my seltup was crazy enough (t-100 ?) to warrant more fuel Id go with an AIC and run 850cc's there too!
That ensures good idel. Good midrange and great top end aswell as more tuneability than the PFC allows and keeps injector cycle duty low enough to never have an issue about a stuck open or overloaded injector!
08-12-01, 11:31 AM
#10
I think the last post is missing some info. For one, what ecu are you using to control the 550/1200 combo? The AIC is another $500 to $850, not counting the $200 you'll spend for 1 injector. Just get a hal-tec and go with the 550/1600 set up, since according to rx7.com's fule calculator, this will net you an estimated 550 flywheel HP at 85% duty cycles. No need to freakin try and tune another injector in with an AIC, more work than is necessary going that route, not to mention more money spent than just a hal-tec. If you go with the PFC, you'll need the boost controller kit to run more than 17 psi anyway since the stock boost sensor isn't meant to go above 17 psi.
Tim Benton
Tim Benton
08-12-01, 05:45 PM
#12
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I'm running the Apexi PFC. I need to bet that boost control kit. Some say that the kit comes with a new solenoid for the PFC, map sensor, and some other crap.
I have a profec B already, don't I only need a new map sensor (like that universal MSD 3 bar map sensor)?
MSD 3 bar map sensor: $50
Apexi boost control kit: $400
"Apexi can kiss my butt."
I have a profec B already, don't I only need a new map sensor (like that universal MSD 3 bar map sensor)?
MSD 3 bar map sensor: $50
Apexi boost control kit: $400
"Apexi can kiss my butt."
08-13-01, 10:14 AM
#16
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Thanks for the tip Gordon. I'm not disregarding Dave and Ari's suggestions, I just wanted to know if it would hurt to have the extra fuel onboard for when ever I needed. (Dave told me it wouldn't cost any more to put the 850's on, just a little more time on the dyno).
By the way, Ari's 550 -1600 setup is changing to the 850 - 1600 set up soon (that's what Rocco at RX7.com told me). That's probably another reason I thought twice about the 850 - 1600 set up. If Ari's going to change it, maybe it wouldn't be such a bad idea to follow.
By the way, Ari's 550 -1600 setup is changing to the 850 - 1600 set up soon (that's what Rocco at RX7.com told me). That's probably another reason I thought twice about the 850 - 1600 set up. If Ari's going to change it, maybe it wouldn't be such a bad idea to follow.
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