less power with bigger shot of nitrous
08-20-2008, 04:04 PM
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less power with bigger shot of nitrous posted on camaroz28 with not much help so i figured id post here :
recently changed my nitrous setup to a stand alone fuel system and put in a nitrous outlet plate. i put a 91 jet in the nitrous and a 82 jet in the fuel and set my regulator at 6.5 psi. i put it on the dyno friday nite and on motor it was the same as last year, i did very little tweaking to get the a/f correct and when i sprayed i set up the fjo progressive to start at 50% and end at 75% with a 2 sec ramp. it then made 436 to the tire(this was on a mustang dyno so the numbers will be lower) i thought that seemed a lil low but went ahead and set it to 100% and only increased to 444 ! (and with my old setup with a nitrous works plate and a 175 shot it made 456hp).thats alot less than the 550 i was hoping for. air fuel was 11.2 to 11.7 all the way through except after 6 grand it went to 10.9. i was running from 3000 rpm to 6000 rpm. and the last pull i went to 6200 rpm thats where it went fat, no biggie since i shift at 5900 anyway.
any ideas on why it would be less power with a bigger shot? this is a 388 lt1 with a 503 cam in and a 4l60e with 3.73 12 bolt, speed density tune. unlocked converter yada yada yada. car has been a best of 10.67 with old setup and went 10.80's saturday with this new setup.
recently changed my nitrous setup to a stand alone fuel system and put in a nitrous outlet plate. i put a 91 jet in the nitrous and a 82 jet in the fuel and set my regulator at 6.5 psi. i put it on the dyno friday nite and on motor it was the same as last year, i did very little tweaking to get the a/f correct and when i sprayed i set up the fjo progressive to start at 50% and end at 75% with a 2 sec ramp. it then made 436 to the tire(this was on a mustang dyno so the numbers will be lower) i thought that seemed a lil low but went ahead and set it to 100% and only increased to 444 ! (and with my old setup with a nitrous works plate and a 175 shot it made 456hp).thats alot less than the 550 i was hoping for. air fuel was 11.2 to 11.7 all the way through except after 6 grand it went to 10.9. i was running from 3000 rpm to 6000 rpm. and the last pull i went to 6200 rpm thats where it went fat, no biggie since i shift at 5900 anyway.
any ideas on why it would be less power with a bigger shot? this is a 388 lt1 with a 503 cam in and a 4l60e with 3.73 12 bolt, speed density tune. unlocked converter yada yada yada. car has been a best of 10.67 with old setup and went 10.80's saturday with this new setup.
08-21-2008, 02:35 PM
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one issue I see is you are ramping the nitrous on the dyno.....this can give you erratic A/F and HP #s.....a progressive is a traction control device not a HP control device.
If you are jetted for 300 hp and set the controller to 50%...this is not a 150 shot...it is a 300 shot 50% of the time. The pulse frequency, solenoid coils, bottle and fuel pressure,and voltage will all affect the speed at which the solenoids pulse.
For tuning purpose set the controller to 100% with no ramp....tune A/F ratio....and verify if you have any convertor slippage by comparing wheel speed vs RPM
If you are jetted for 300 hp and set the controller to 50%...this is not a 150 shot...it is a 300 shot 50% of the time. The pulse frequency, solenoid coils, bottle and fuel pressure,and voltage will all affect the speed at which the solenoids pulse.
For tuning purpose set the controller to 100% with no ramp....tune A/F ratio....and verify if you have any convertor slippage by comparing wheel speed vs RPM
08-21-2008, 03:25 PM
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after i tried the 50% to 75% with a ramp i set it to 100% with no ramp and still only made 444hp, with the air/ fuel perfect.i will prob get on dyno again saturday and check the slippage issue
08-21-2008, 03:37 PM
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what heads are on the car?
my old combo had a set of LT1 casting that made 500whp on 150 shot and 525 on a 200 Shot this was on a baseline of 390whp....swapped in a better set of heads and the car made 507 on a 100 shot and 618 on the 200 shot...on a 400hp baseline.
my old combo had a set of LT1 casting that made 500whp on 150 shot and 525 on a 200 Shot this was on a baseline of 390whp....swapped in a better set of heads and the car made 507 on a 100 shot and 618 on the 200 shot...on a 400hp baseline.
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08-22-2008, 07:29 PM
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perfect air fuel should be around 11.5, which is where im at, another thing is my converter is unlocked. should i lock it and see what it does?
08-23-2008, 07:26 AM
#10
I run my car at 12.3-12.5 on 300+ of N20 and the plugs look good.
Locking the converter will just give you a number on the dyno, take it to the track and run it that will tell you if its making power. Do you lock it at the track?
08-23-2008, 07:40 AM
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well im gonna try and lean it out a bit today on the dyno, and do a lil more tweaking to it. no i have never had it locked,it has a manual valve body and im not sure i can even lock it. i talked to my tranny guy last nite and he said he didnt think i still could with the valve body. i may try a lil smaller shot and see what that does, may it is just to much for it.
08-23-2008, 08:43 AM
#12
Shut the car off quickly at the end of a pull and check some plugs, they should look almost new. if they have color on them its still to rich.
Dont lock the converter (sounds like its not an option anyway) your trying to simulate racing and if you dont race that way dont dyno it that way.
Dont lock the converter (sounds like its not an option anyway) your trying to simulate racing and if you dont race that way dont dyno it that way.
08-23-2008, 08:54 AM
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ok will do, the numbers dont matter to me i just want it to be right but when u make less with more it gets aggravating,. i just want to lock the converter for better mpg. i got 17.5 my last tank and went and ran a 10.84 the next day, thats a good street car , just needs to be faster
08-27-2008, 07:43 AM
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well put it on the dyno again last night, picked up 13hp from changing the fuel pump in the tank. so new n/a numbers is 321hp 322 tq, and sprayed it on 100% with no delay or ramp time and it made the same 444 as it did last time, it was blowing a lil tranny fluid out the tail shaft, so im just gonna put on my t400 tomorrow and dyno again on friday and see what that does.hopefully it will pick up some major hp. i will let u know sat morning
08-27-2008, 01:53 PM
#15
The tranny issue is a good point but what about that controller? FJO makes great stuff but sometimes stuff goes bad. But in my opinion we need to look at the electronics, solenoids, controller, tuner (wink, wink) just kidding Ryan!
09-02-2008, 07:27 AM
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ok switched to my turbo 400, i got skinnies old converter, it flashed way to high on spray but still made only 430 hp. put im my converter, flashed alot lower but still only made 428. on a 300 shot, i put in a 102 jet and only increased to 433 hp. 2 different trannys and 3 converters later im still not putting down the power it should., it has to be a restriction somewhere on the nitrous side, i went from a 82 jet at 6.5 psi to a 76 jet on the fuel side and was still rich, i dropped to 5.5 psi and it was still rich., i took the nitrous solenoid apart and it was clean, im gonna try a new line from bottle to solenoid, and see what that does
09-02-2008, 10:37 AM
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thats your issue...a 3AN line will only support 175 or so nitrous flow but will handle the flow for 300 plus on the fuel side....you are max flowing the line and not controlling the flow with the jet.
you need to upgrade the nitrous side to this....
http://www.nitrousoutlet.com/catalog...roduct_id=2616
its a 4AN line with a 3AN nut on one end to attach to the plate.
You will also need a new fitting for the solenoid....I am assuming the solenoid has a 1/8npt port...
http://www.nitrousoutlet.com/catalog...roduct_id=2704
you need to upgrade the nitrous side to this....
http://www.nitrousoutlet.com/catalog...roduct_id=2616
its a 4AN line with a 3AN nut on one end to attach to the plate.
You will also need a new fitting for the solenoid....I am assuming the solenoid has a 1/8npt port...
http://www.nitrousoutlet.com/catalog...roduct_id=2704