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S3 bridge port motor in 91 lemons car

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Old Feb 16, 2011 | 04:05 PM
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Exclamation S3 bridge port motor in 91 lemons car

ok guys i know this is gheto rigged but we are trying to get this car running for a lemons race
hers a break down of what is in the car

its a 91 vert. The motor was supposed to be a street port but ended up being a small bridge port when we picked it up. The motor is from an 85.

What we have done so far

we have the S5 intake stuff on it. ground down the housing and such.
it has an ebay header on it
it has a 255 fuel pump on it although im sure this isnt needed.
still has stock injectors and stock ecu
obviously the car is incredibly hard to start as it sits and wont run for long.


now the question is, is there a ghetto way to make this car run using the stock ECU. such as an adjustable fuel regulator with the pressure jacked way up. or possible running larger injectors with the stock ecu.

I know this isnt going to be optimal or the best performing way to go about this but we just want the car to be able to race.

Our only other option that we didnt want to have to do would be to use a megasquirt. How difficult is this to get running using the stock harness or is that even possible. I know there are maps online to download for atleast a starting point for tuning.

So if you can help suggest a way to make this car run please give your input.
thanks
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Old Feb 16, 2011 | 05:03 PM
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also forgot to add, it has the s5 from cover on it and the 91 ignition parts instead of the dizzy
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Old Feb 16, 2011 | 05:48 PM
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With a walbro 255 pump & stock FPR in there you'll already end up with higher-than-stock fuel pressure. You'll be looking at roughly 10 psi higher fuel pressure under all conditions, so that'll boil down to roughly 10% more fuel being pushed through the injectors. So...are you using four 460cc injectors, or two GSL-SE 680cc injectors? I'm assuming 4x460cc since it sounds like you're using the S5 ECU for control.

If using four 460cc injectors, I think the real question is do you even need more fuel? Stock injectors are good to about 200 whp, and the flow limitations of the S5 intake will probably put you below that point.
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Old Feb 16, 2011 | 06:17 PM
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Originally Posted by RotaryRocket88
With a walbro 255 pump & stock FPR in there you'll already end up with higher-than-stock fuel pressure. You'll be looking at roughly 10 psi higher fuel pressure under all conditions, so that'll boil down to roughly 10% more fuel being pushed through the injectors. So...are you using four 460cc injectors, or two GSL-SE 680cc injectors? I'm assuming 4x460cc since it sounds like you're using the S5 ECU for control.

If using four 460cc injectors, I think the real question is do you even need more fuel? Stock injectors are good to about 200 whp, and the flow limitations of the S5 intake will probably put you below that point.
yes 4 460s. That was our whole concern. the car is really hard to start and wont stay running. that is why we were thinking about using the megasquirt. Even with starter fluild and the fuel pump unplugged the car is still hard to start. I know this is not a good test but Ive seen many a cars run off strait starter fluid for a bit.

I guess another question would be,
Since the "short block" is S3, and the front cover and main pulley is S5. is it possible that the timing marks are not correct? Im not sure if there is a difference in the pulleys from series to series. But again we are using the S5 trigger wheel and ignition
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Old Feb 16, 2011 | 06:45 PM
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How much overlap did you put into the port?
Are you using a wideband to tune, if so, are you running rich or lean?
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Old Feb 16, 2011 | 06:48 PM
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Originally Posted by Pele
How much overlap did you put into the port?
Are you using a wideband to tune, if so, are you running rich or lean?
honestly the motor was bought already ported and from a running car.
We cant even get a reading on the wideband because the car wont stay running long enough or smooth enough to get a reading. we have tried all different positions turning the CAS. and it starts the easiest when put in there using the factory settings
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Old Feb 16, 2011 | 11:27 PM
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Originally Posted by RotaryRocket88
With a walbro 255 pump & stock FPR in there you'll already end up with higher-than-stock fuel pressure. You'll be looking at roughly 10 psi higher fuel pressure under all conditions, so that'll boil down to roughly 10% more fuel being pushed through the injectors.
Uh... No.
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Old Feb 16, 2011 | 11:31 PM
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Originally Posted by Red95T-Rex
ok guys i know this is gheto rigged but we are trying to get this car running for a lemons race
hers a break down of what is in the car

its a 91 vert. The motor was supposed to be a street port but ended up being a small bridge port when we picked it up. The motor is from an 85.

What we have done so far

we have the S5 intake stuff on it. ground down the housing and such.
it has an ebay header on it
it has a 255 fuel pump on it although im sure this isnt needed.
still has stock injectors and stock ecu
obviously the car is incredibly hard to start as it sits and wont run for long.


now the question is, is there a ghetto way to make this car run using the stock ECU. such as an adjustable fuel regulator with the pressure jacked way up. or possible running larger injectors with the stock ecu.

I know this isnt going to be optimal or the best performing way to go about this but we just want the car to be able to race.

Our only other option that we didnt want to have to do would be to use a megasquirt. How difficult is this to get running using the stock harness or is that even possible. I know there are maps online to download for atleast a starting point for tuning.

So if you can help suggest a way to make this car run please give your input.
thanks
There isn`t going to be any real way to make the engine run well with a stock ECU. The fuel and timing maps change significantly on a BP engine.
Best bet is likely going to be a megasquirt. You can pick up a used plug and play unit, or build your own and wire it to the stock harness. Even better, build a new harness. There are maps available that`ll run your engine pretty well, if not, I`ve got a tuned bridge-460cc injector map you can use that`ll run your engine pretty well.
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