1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

S5 TII to go EFI or Carb???

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Old Sep 6, 2008 | 10:39 PM
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S5 TII to go EFI or Carb???

Ok I have a dillema I have S5 TII broken donw in my garage getting ready to rebuild and my biggest dillema right now is eather try to get the EFI working or just say srew it and get a holley 650 carb port the **** out of the motor and run it like that. The only problem is that I would have to use stock ECU if I went the EFI way. Any input is greatlly apreciated.
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Old Sep 6, 2008 | 10:42 PM
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Are you familiar with the wiring harnesses? If not do you want to become familiar with them, if not then carb it.
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Old Sep 6, 2008 | 11:33 PM
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TII motors are low comp. If you carb it, you'll have to build some kind of blow-through turbo setup, it wouldn't run N/A.

If you have a complete setup including ECU and harness then go EFI. If you don't have the harness or the ECU, get a standalone. Then again, if you're more comfy with carb, run with it. It's really a question of how much money, time, and effort you want to put in and how much do you know about either option already.

Jon
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Old Sep 7, 2008 | 12:10 AM
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It would run just fine NA. S5 is 9.0:1. The old ACVW engines went at least as low as 6.8:1. It's not like you're boosting while cranking.

But I would recommend a smaller carb than that. I'd run a 48 IDA if I didn't like fuel injection. But if it was my engine I'd ditch the stock ECU and wiring and run a MegaSquirt. It's cheaper anyway.

Last edited by PercentSevenC; Sep 7, 2008 at 12:20 AM.
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Old Sep 7, 2008 | 07:54 AM
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I am going turbo I got the motor as a long block so everything is there I need a few more wires for the coils and the CAS and the MAF to run stock ecu I just cant swing for stand alone right now I have a baby on the way and a lot more house work to get finished before that and if I dont get the car done now I dont know if it will get done anytime soon after that so Iwas just wondering witch way would be simpler to do carb or efi.
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Old Sep 7, 2008 | 08:33 AM
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Originally Posted by PercentSevenC
It would run just fine NA. S5 is 9.0:1. The old ACVW engines went at least as low as 6.8:1. It's not like you're boosting while cranking.

But I would recommend a smaller carb than that. I'd run a 48 IDA if I didn't like fuel injection. But if it was my engine I'd ditch the stock ECU and wiring and run a MegaSquirt. It's cheaper anyway.
+1

Very well put. I have a turbo motor that I've been running NA for 3 months while waiting for some additional mods and a tune before I hook up the tube from the IC to the intake. It runs just fine.
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Old Sep 8, 2008 | 08:38 PM
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From what I have experienced Holley carbs will tend to bog in hard corners. FI is the way to go. Spend some time, learn the wiring and keep the FI.
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Old Sep 8, 2008 | 11:15 PM
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Originally Posted by vipernicus42
it wouldn't run N/A.
Even if he had an S4, which is like 8.6, it would still run NA. Older rotaries had 9.2 compression ratios and were NA. That's just .2 more than S5 T2. They run fine. Sheeshkamunga!

Last edited by Jeff20B; Sep 8, 2008 at 11:18 PM.
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Old Sep 13, 2008 | 11:14 AM
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go carb and avoid the efi wiring headache, even if it means using a holley
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