New Injector Opinion
#1
24 yrs driving 2nd Gen RX
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New Injector Opinion
Hi Gang,
Looks like I'm going to have to replace the primary injectors. I have a pair of 550cc that are good (but unknown mileage) I could put in, but while the LIM 'nstuff is off, I wonder if I should just replace them with new and possibly larger.
Here's my setup now:
Atkins Street Port
Racing Beat TurboII 3"
Stock Turbo
550cc Primary
RC Engineering 750cc Secondary
Walbro pump
Aeromotive FPR
Microtech LTX12s
Innovate LC-1 wideband
So my question: what would you do?
New RCEng 750cc?
New RCEng 550cc?
New RCEng something larger?
New somebody else's something else?
Something else?
Going for 300+ HP goal.
- kel -
Looks like I'm going to have to replace the primary injectors. I have a pair of 550cc that are good (but unknown mileage) I could put in, but while the LIM 'nstuff is off, I wonder if I should just replace them with new and possibly larger.
Here's my setup now:
Atkins Street Port
Racing Beat TurboII 3"
Stock Turbo
550cc Primary
RC Engineering 750cc Secondary
Walbro pump
Aeromotive FPR
Microtech LTX12s
Innovate LC-1 wideband
So my question: what would you do?
New RCEng 750cc?
New RCEng 550cc?
New RCEng something larger?
New somebody else's something else?
Something else?
Going for 300+ HP goal.
- kel -
#3
24 yrs driving 2nd Gen RX
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#5
24 yrs driving 2nd Gen RX
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#6
Top Down, Boost Up
iTrader: (7)
If you're sticking with the stock turbo, you'll only need 720 or 750cc secondaries. The 720s I use are a pair of Greddy/Denso injectors. They're a little expensive, but they're quality parts. I just switched out my injectors in preparation for a hybrid turbo, but the 550/720cc setup was operating at 73% duty cycle max & 11.5 AFR with the stock turbo giving it all it had.
#7
24 yrs driving 2nd Gen RX
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If you're sticking with the stock turbo, you'll only need 720 or 750cc secondaries. The 720s I use are a pair of Greddy/Denso injectors. They're a little expensive, but they're quality parts. I just switched out my injectors in preparation for a hybrid turbo, but the 550/720cc setup was operating at 73% duty cycle max & 11.5 AFR with the stock turbo giving it all it had.
With stock turbo, you say I won't gain by increasing the primary size? A turbo upgrade could be in the future, but for now, I need to stay with the stock unit.
THX
- kel -
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#8
Top Down, Boost Up
iTrader: (7)
As long as you're staging the secondaries at about 3500 RPM or lower, 550cc primaries will not max out before the secondaries come online. If using the stock 3800 RPM switch point, they will hit max duty cycle and cause a small lean spot with elevated boost levels. And as far as total fuel delivery, 550/750 will be more than the stock turbo needs.
If you're wanting to go bigger for later upgrades, you'll probably be better off just using larger secondaries with the 550cc primaries. If you leave the primaries alone, you won't have to adjust as much of the fuel map. Idle, start up and the vacuum parts of the map will be affected by increasing primary size.
If you're wanting to go bigger for later upgrades, you'll probably be better off just using larger secondaries with the 550cc primaries. If you leave the primaries alone, you won't have to adjust as much of the fuel map. Idle, start up and the vacuum parts of the map will be affected by increasing primary size.
Last edited by RotaryRocket88; 05-23-11 at 11:31 AM.
#9
24 yrs driving 2nd Gen RX
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As long as you're staging the secondaries at about 3500 RPM or lower, 550cc primaries will not max out before the secondaries come online. If using the stock 3800 RPM switch point, they will hit max duty cycle and cause a small lean spot with elevated boost levels. And as far as total fuel delivery, 550/750 will be more than the stock turbo needs.
If you're wanting to go bigger for later upgrades, you'll probably be better off just using larger secondaries with the 550cc primaries. If you leave the primaries alone, you won't have to adjust as much of the fuel map. Idle, start up and the vacuum parts of the map will be affected by increasing primary size.
If you're wanting to go bigger for later upgrades, you'll probably be better off just using larger secondaries with the 550cc primaries. If you leave the primaries alone, you won't have to adjust as much of the fuel map. Idle, start up and the vacuum parts of the map will be affected by increasing primary size.
Thanks again for your thoughtful replies.
- kel -
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