what's the fastest
what's the fastest
built my own engine
Joined: Dec 2002
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From: Buckhead, Atlanta
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11.7@128
Joined: Mar 2004
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From: new jersey
thanks. the reason i asked is because i just got an fd and was thinking of going single since i'm also getting a rebuild /streetport. Someone I spoke to recently reccomended that i keep the stock twins until they quit. Any advice? thanks
FD = Mr. Toad's Wild Ride
Joined: Mar 2004
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From: San Antonio, TX
I personally don't want to give up the lower RPM power that the sequential twins give despite the added complexity of the system.
If your car is mainly for street use how much HP do you really need? You can run in the mid 11s 1/4 mile with cat-back exhaust, cold air intake, pully kit, boost controller (watch those spikes), and PFC/tuned ECU and 12-14PSI. If you are having a hard time maintaining boost look at replacing stock Y-pipe with Efini (forum concensus I've read is you pickup about 1lb of boost from that).
You'll want an AFU/O2 sensor/gauge for tuning and keeping an eye out so you don't kaboom but the stock injectors should keep up with that setup.
All of those changes even leave you able to pass emissions in any state (you'll need a smog testing map for the PFC that doesn't run rich at low RPM).
The limit on your 0-60 time once you start adding much HP at all to the FD will be traction. You might be able to pull a few nice launches at big HP numbers but one bad launch with a lot of wheel hop and you're broken. Since most singles spool at such a high RPM its hard to launch clean in them so you may actually end up slower 0-60 (and almost for certain on the 60') than a sequential twin setup.
I started a thread about this on the Race Car Tech section with a poll. Some good comments are there as well as some informative voting.
https://www.rx7club.com/showthread.p...hreadid=295358
If your car is mainly for street use how much HP do you really need? You can run in the mid 11s 1/4 mile with cat-back exhaust, cold air intake, pully kit, boost controller (watch those spikes), and PFC/tuned ECU and 12-14PSI. If you are having a hard time maintaining boost look at replacing stock Y-pipe with Efini (forum concensus I've read is you pickup about 1lb of boost from that).
You'll want an AFU/O2 sensor/gauge for tuning and keeping an eye out so you don't kaboom but the stock injectors should keep up with that setup.
All of those changes even leave you able to pass emissions in any state (you'll need a smog testing map for the PFC that doesn't run rich at low RPM).
The limit on your 0-60 time once you start adding much HP at all to the FD will be traction. You might be able to pull a few nice launches at big HP numbers but one bad launch with a lot of wheel hop and you're broken. Since most singles spool at such a high RPM its hard to launch clean in them so you may actually end up slower 0-60 (and almost for certain on the 60') than a sequential twin setup.
I started a thread about this on the Race Car Tech section with a poll. Some good comments are there as well as some informative voting.
https://www.rx7club.com/showthread.p...hreadid=295358
I got 118 trap speeds but only a 12.42 while breaking my diff and PPF due to retarded wheel hop on street tires.
I still have stock sequential twins and a mild streetport. See for yourself on the dyno numbers and nice torque curve of em. I keep the sequential for drivability even though non-sequential is proven to provide more power, it's not as nice to drive around town.
I've put almost 80k miles on these rebuilt twins beating the **** out of them, so there for your reliability. My car has just about 180k miles on it, and these turbos were rebuilt once
AND there is NO F@#% way to go mid 11's on the stock injectors. Ain't happening.
EDIT sorry, couldn't get dyno chart post, will try again later
I still have stock sequential twins and a mild streetport. See for yourself on the dyno numbers and nice torque curve of em. I keep the sequential for drivability even though non-sequential is proven to provide more power, it's not as nice to drive around town.
I've put almost 80k miles on these rebuilt twins beating the **** out of them, so there for your reliability. My car has just about 180k miles on it, and these turbos were rebuilt once
AND there is NO F@#% way to go mid 11's on the stock injectors. Ain't happening.
EDIT sorry, couldn't get dyno chart post, will try again later
Last edited by fitzrx7; Apr 22, 2004 at 10:35 PM.
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Joined: Feb 2001
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From: Union, NJ
<<<I think anything is possible with stock twins and a ULTRA light 7! LoL>>>
Ran 10.98 back in Nov of 2003 in full weight (2940lbs) and 18 psi on pump gas (94 oct).
With 4x 850cc injectors I ran 11.56 @ 122mph maxxing them out...
Ran 10.98 back in Nov of 2003 in full weight (2940lbs) and 18 psi on pump gas (94 oct).
With 4x 850cc injectors I ran 11.56 @ 122mph maxxing them out...
Eats, Sleeps, Dreams Rotary
Joined: May 2003
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From: MIA
Originally posted by Boostn7
<<<I think anything is possible with stock twins and a ULTRA light 7! LoL>>>
Ran 10.98 back in Nov of 2003 in full weight (2940lbs) and 18 psi on pump gas (94 oct).
With 4x 850cc injectors I ran 11.56 @ 122mph maxxing them out...
<<<I think anything is possible with stock twins and a ULTRA light 7! LoL>>>
Ran 10.98 back in Nov of 2003 in full weight (2940lbs) and 18 psi on pump gas (94 oct).
With 4x 850cc injectors I ran 11.56 @ 122mph maxxing them out...
Banned. I got OWNED!!!
Joined: Sep 2003
Posts: 261
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From: CA
comment: Howcome american people are mainly focusing on the horse power and the 1/4mile ?
I think thats a waste of FD.
I personally enjoy driving places where I can put my FD to use and enjoy the handling. (up in the hills, road racing)=)
Anyone feel me ova here??
I think thats a waste of FD.
I personally enjoy driving places where I can put my FD to use and enjoy the handling. (up in the hills, road racing)=)
Anyone feel me ova here??
proper motoring
Joined: Jan 2004
Posts: 1,706
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From: USA
have ya seen Nascar? yeah, there ya go. americans, fast, lots of power, and the only reason it goes in a circle is because a 500 mile straight track would cost too much to build, decrease the cost of sponsor adds, etc. i never got it to, but you have to admit, feeling like your *** is in the storage bins is fun always been a road fan myself though
always been a road fan myself though
Hopefully this links works to the dyno sheet.
Jon Fitz/ 12.5 psi stock twins /'03
That is a mild streetport with stock sequential twins. On top of that the second turbo has a bent compressor fin and has been running fine like that for 40k miles now. No oil burning, perfect transition. Thanks to Chuck for the stellar timing maps.
Jon Fitz/ 12.5 psi stock twins /'03
That is a mild streetport with stock sequential twins. On top of that the second turbo has a bent compressor fin and has been running fine like that for 40k miles now. No oil burning, perfect transition. Thanks to Chuck for the stellar timing maps.
Originally posted by fitzrx7
AND there is NO F@#% way to go mid 11's on the stock injectors. Ain't happening.
AND there is NO F@#% way to go mid 11's on the stock injectors. Ain't happening.
1/4 mile time 11.42
1/4 mile MPH 120.60
358RWHP is the theoretical maximum for wheel horsepower with the stock injectors and fuel pressure.
see http://rx7.com/cgi-local/3rdgencalc.cgi
I can pretty well say that the current HP output of this car is not possible on the stock fuel system.
There is a possibility of breaking into high 11's on the stock fuel system with drag slicks...and I am sticking to not being able to do mid 11's (11.4-11.6) on stock fuel.
see http://rx7.com/cgi-local/3rdgencalc.cgi
I can pretty well say that the current HP output of this car is not possible on the stock fuel system.
There is a possibility of breaking into high 11's on the stock fuel system with drag slicks...and I am sticking to not being able to do mid 11's (11.4-11.6) on stock fuel.
Last edited by fitzrx7; Jun 2, 2004 at 10:31 PM.
Originally posted by fitzrx7
358RWHP is the theoretical maximum for wheel horsepower with the stock injectors and fuel pressure.
358RWHP is the theoretical maximum for wheel horsepower with the stock injectors and fuel pressure.
Originally posted by Wade
"Safely" is a relative term, safety doesn't have as much to do with the duty cycle of your injectors as it does everything else like charge temp, a:f ratio, timing. PFS is right on this one, think of PFS whatever you want (good or bad, I couldn't care less) but an FD can certainly make 400 rwhp with the stock injectors, it has been done.
I'm not sure why so many people freak out about hitting high duty cycles with stock injectors. Here are some things to consider:
1) I don't know anyone who has had an injector failure from driving the stock ones at high duty cycles, and a lot of people have done this for YEARS
2) I DO know several people who had enlarged injectors fail
3) There is no reason why an injector should fail just because it is staying open instead of clicking on and off several times per second... someone explain to me their reasoning on this!
4) It is the fuel injection companies that are telling you that beyond 85% duty is a bad thing, big surprise
5) I think beyond 85% *IS* a bad thing in a sense because it leaves no more room for mods if your a:f is exactly where you want it, you could lose tuning flexibility... but I wouldn't freak out about thinking my engine would blow because my duty cycles are high
6) High duty cycles only occur right near redline anyway, we're talking about a second or two when raking through the gears unless you are going for a top speed run at Bonneville
My conclusion is there is no need to upgrade injectors until there is a NEED to upgrade injectors. I run 15psi of boost with stock injectors and pressure and have been hitting 100% duty for almost 4 years now. If one of my injectors fails I'll know it and I highly doubt I'll blow my engine because of it.
Wade
"Safely" is a relative term, safety doesn't have as much to do with the duty cycle of your injectors as it does everything else like charge temp, a:f ratio, timing. PFS is right on this one, think of PFS whatever you want (good or bad, I couldn't care less) but an FD can certainly make 400 rwhp with the stock injectors, it has been done.
I'm not sure why so many people freak out about hitting high duty cycles with stock injectors. Here are some things to consider:
1) I don't know anyone who has had an injector failure from driving the stock ones at high duty cycles, and a lot of people have done this for YEARS
2) I DO know several people who had enlarged injectors fail
3) There is no reason why an injector should fail just because it is staying open instead of clicking on and off several times per second... someone explain to me their reasoning on this!
4) It is the fuel injection companies that are telling you that beyond 85% duty is a bad thing, big surprise
5) I think beyond 85% *IS* a bad thing in a sense because it leaves no more room for mods if your a:f is exactly where you want it, you could lose tuning flexibility... but I wouldn't freak out about thinking my engine would blow because my duty cycles are high
6) High duty cycles only occur right near redline anyway, we're talking about a second or two when raking through the gears unless you are going for a top speed run at Bonneville
My conclusion is there is no need to upgrade injectors until there is a NEED to upgrade injectors. I run 15psi of boost with stock injectors and pressure and have been hitting 100% duty for almost 4 years now. If one of my injectors fails I'll know it and I highly doubt I'll blow my engine because of it.
Wade
R1ownesYou
Joined: Mar 2004
Posts: 46
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From: Atl
aside from times...stock twins are way hotter than any single. With loss of excess solonoids and all sorts of crap, the car also seems to run a bit better with the upgrade. I use a T70. There is not as much lag as you might think...it may not boost as low in rpms, but full boost is attained about the same as stock.
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