STS problems help!!!!!!!!
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From: Thibodaux Louisiana
STS problems help!!!!!!!! I just installed a 5 psi kit on a 02 firehawk .The car is all stock other than the turbo, injectors (42#) and 3200 vig converter. He went to get it tuned and the car pulls good to 4500 RPM then it just stops making power. They swapped plugs and still the same result. I'll try to post up the dyno sheet A.S.A.P oh and the plugs are TR6's. The car is still making 5.5LBS at 4500 but the car just falls on it's face as far as power. Any ideas ? Valve springs? Help guys anyone had this problem before?
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From: Ft. Irwin, California (But Virginia is home)
If the car has a stock fuel system (ie stock pump) and stock springs.....either could cause the problem described. I'd address the valvespring issue first, as float will definetly cause the problem using stock springs. Running out of fuel is also possible on the stock pump. Not a good thing either and the symptoms for that are similiar too.
Good luck
Good luck
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From: Thibodaux Louisiana
the Afr is good but the springs is what i was thinking once the fresh plugs were in and it was still doing the same thing. And if springs are upgraded so will the push rods. Do you think 918's will be sufficient?
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From: Ft. Irwin, California (But Virginia is home)
Forgot about the pushods. Change the springs....and the rods so they don't bend under the higher spring pressure. Make sure your tuner knows what he is doing. Datalogging is essential to any good tune and will probably answer your question.
Fuel Pump issue...
Injector Duty Cycle...
Valve float....
etc.
-Wade
Fuel Pump issue...
Injector Duty Cycle...
Valve float....
etc.
-Wade
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From: Thibodaux Louisiana
It's being tuned at Thunder racing. One of the best in the area.But after two days it still has them scratching their heads lol I'm sure they will figure it out though.I just thought someone on here might have encountered the same problem before. I haven't seen the dyno sheet yet but from what they are telling me it's not getting ragged and falling off at 4500 its just leveling out like a plateau. They seem to think it might be bad cats. And the owner is thinking of letting them fab up a ORY for it but from what I'm told that will be extremely loud.I've heard some guys are putting bullet mufflers in the tailpipe after the turbo. How well does that work?
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From: Thibodaux Louisiana
Well chris at sts also said the cats (stock ) could cost as much as 30-40 hp But high flows work well. I'll give the owner of the car a call he is going pick it up today
i'd say there is a 95% chance the problem is the springs. Everyone trys to cheap out on the valve springs for some reason. Stock springs are not strong enough. I floated the valves and customized my pistons on 918's but they should be ok if you keep the boost below 12psi.
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From: Bellevue, Wa
I agree with springs. Kinda suprised a shop like Thunder would even be scratching their head on that one.
I only have 915's and they are 6 years old now and the car now stops pulling right about the same place as yours circa 5000 rpm on just 5.5psi. Pulls great til then and then just falls over and I know it's not my tune.
Dual valve springs are in my future one of these days.
Get those springs upgraded and let us know how it turns out.
I only have 915's and they are 6 years old now and the car now stops pulling right about the same place as yours circa 5000 rpm on just 5.5psi. Pulls great til then and then just falls over and I know it's not my tune.
Dual valve springs are in my future one of these days.
Get those springs upgraded and let us know how it turns out.
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From: Thibodaux Louisiana
I'll do that i just wanted to check on here to see if anyone had any ideas other than the valve springs. Thunder thinks it may be bad cats. I'll post up results.
I just installed a 5 psi kit on a 02 firehawk .The car is all stock other than the turbo, injectors (42#) and 3200 vig converter. He went to get it tuned and the car pulls good to 4500 RPM then it just stops making power. They swapped plugs and still the same result. I'll try to post up the dyno sheet A.S.A.P oh and the plugs are TR6's. The car is still making 5.5LBS at 4500 but the car just falls on it's face as far as power. Any ideas ? Valve springs? Help guys anyone had this problem before?
