63 replies to this topic

[david kriedeman]

HI QSS members,
thought i would start a new thread on N2O.
There seems to be alot of interest regarding this TRUELY EFFICIENT & INSTANT POWER ADDER.
The most common comments most people hear regarding NITROS, are MOSTLY INCORRECT.
I have been installing & tuning NITROS SYSTEMS for many years now.
I have never myself had any problems with the substance.
Over the years i have fitted many WET & DRY SYSTEMS,CARBY & EFI SYSTEMS,DIRECT PORT,PRO FOGGER ETC.
The most UNUSUAL system i have ever fitted was a NOS SYSTEMS twin fogger set up on an 850 cc SEADOO. (JET SKI)
I will give information regarding N2O, how it works,what you should do & look out for.
How to tune your engine for nitros,pro & cons,master over ride systems (watch dogs)
Fuel SYSTEM set ups etc, ENGINE INTERNAL requirements, IGNITION CURVE STRATEGIES etc.
If you need technical assistance with this product or a general enquirey,
POST AWAY MY FRIENDS, i will see if i can help.
THIS STUFF ""KICKS ARSE""

[mr-squiggle]

nitrous has been in my family my whole life... and it has never done any damage to any of the cars my father has built, most of the cars we set up were completly stock and were running 1-2secs faster down the 1/4... i dont know why people always say "nitrous will blow up and engine!" cause it wont if you use it sensibly... you will blow up an engine if you put a 250 shot into a stock engine.

my father was the australian dealer for nitrous express, and we had a kit on the torana which made the car run under 10secs which made it the 3rd fastest street legal car in queensland.

but if you guys want to have some fun, nitrous is so fun, and its not cheating because anyone can put a kit onto a car, and it is a "modification" that can be done to a car.

P.S. people using forced induction, if you want to put a 150shot in, use 75shot jets... always half if forced induction

[ferret]

I wanted to run a 100 shot in the gemini. Since it's a twin turbo'd 8 what're your thaughts. The motor is a 253 will be carbed unless someone wants to donate an injection kit. Running stock every thing except pistons and rings. it has been decompressed to 8.5 - 1 and is running 2 x T3/4's.

The motor is still sitting waiting for rings but i want to get all the parts together before it all gets built. Makes it a bit easier.

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[david kriedeman]

Hi FERRET,
How much boost are you going to run & how many RPM will you be turning your engine too.
I would suggest you do some CONROD STRENGTHENING MODS to your stock rods.
Remove all casting flash marks ,ridges,etc.
Give an overall polish, to rid each rod of all of it's casting inporfections.
Fit good quality rod bolts(ARP).
Have CONRODS RESIZED.
The best thing to do regarding the CONRODS is to BIN them and fit some SCAT or EAGLE type billet 4340 steel,thats if you can afford to do so.
FORGED pistons are a definate if you wish to run BOOST & N2O.
You can get away with cast pistons or hyperautectics,but wouldn't recommend.
These pistons are less forgiving compared to forged.
MAXIMUM suggested N2O limit on NON-FORGED pistons is 100hp.
However i have run 125hp on several engines with cast pistons without issues,coupled with the correct amount of spark retard & good quality fuel systems.
BOOST & GAS, CAST OR HYPERAUTECTIC PISTONS, NO THANKS.
You need to finalise your combination,as far as induction system set up etc before i can give you any more help with your inquirey.
Hard to advise with unknown factors.
"""WHEN SELECTING A CAMSHAFT,I STRONGLY RECOMMEND GETTING a CUSTOM GROUND CAMSHAFT for your ENGINE"""
NORMAL CAMSHAFT REQUIREMENTS:
1. FORCED INDUCTION= WIDER LOBE SEPERATION,LESS DURATION AT 0.050", MORE LIFT.
THE ABOVE IS REQUIRED TO MINIMISE VALVE OVERLAP.
2.NITROS OXIDE= MORELIFT, DURATION AT 0.050" dependant on engine combo and at what MAX. RPM will be and at what RPM you want the engine to start making power.
3. NORMALLY in a N2O only engine combo, you would use what we refer to as a DUAL PATTERN CAMSHAFT.
Meaning the EXHAUST LOBE has MORE DURATION than the INLET LOBE.
(EXHAUST VALVE is OPEN LONGER THAN THE INLET VALVE) You need a combination of both 1,2&3.

Edited by david kriedeman, 16 July 2006 - 05:15 AM.

[Graham]

any thoughts on a small system on a sr20det? for short burst on a circuit? not for the drags?

what sort of info would you need to enlighten me?

[david kriedeman]

Hi GRAHAM,
Your SR20DET will respond very well with a shot of GAS.
Probably the best all round NITROS KIT available for most EFI vehicles is the ZEX EFI DRY SYSTEM.
These systems work extremely well,simple to install & easily activated.
The ZEX system has a very interesting set up compared to most systems.
I wouldn't run anything more than 100hp shot. (if ENGINE has stock INTERNALS)
Starting HP set is a 75hp KICK IN THE PANTS.
SYSTEM OPERATION OVERVEIW:
DRY SYSTEM = NITROS OXIDE ONLY,is injected into the inlet tract.
WET SYSTEM = NITROS & FUEL, are injected into the inlet tract.
The ZEX DRY SYSTEM uses a single fogger nozzle to discharge the N2O through.
All NITROS SYSTEMS need activation systems employed for the units to function.
Most systems come with a MASTER ARMING SWITCH, normally mounted in the dash or an appropriate easy to get at position and a FULL THROTTLE MICRO SWITCH.
Normally the bottle tap must be turned on(OPENED),
The MASTER ARMING SWITCH must be turned on,
Then the full throttle MICRO SWITCH is actvated at WIDE OPEN THROTTLE (W.O.T)
ZEX SYSTEMS EFI dont use a FULL THROTTLE MICRO SWITCH, they EMPLOY the all ready used THROTTLE POSITION SWITCH (TPS).
The SYSTEM consists of :
10 LB BOTTLE (standard) & MOUNTING BRACKETS and assoc. hardware.
LENGTH of STAINLESS STEEL BRAIDED TEFLON SUPPLY HOSE.
SINGLE SUPPLY N20 FOGGER NOZZLE
A selection of both NITROS & FUEL JETS (ranging from 75,100,125 HP)
A CONTROL MODULE ( which also houses the SOLENOID ASSEMBALLIES)
MASTER ARM SWITCH.
NOT ALOT TO IT.
The complete system has ONLY 3 WIRES to HOOK UP for a basic installation ready to run.
These 3 wires are :
1. IGNITION SUPPLIED 12 volts via the master arming switch.
2. EARTH.
3.TPS SIGNAL RETURN INPUT.
The ZEX MODULE ASSEM. is the BRAINS in the SYSTEM.
The way this system works is UNBELIEVABLY SIMPLE & VERY CLEVER in its FUNCTIONAL OPERATION.
The ZEX EFI DRY SYSTEM works as follows,
When the complete system is installed,the following is required.
""""WARNING,WARNING"""" MAKE SURE THE MAIN SUPPLY HOSE FROM THE N2O BOTTLE is COMPETELY DISCONNECTED & THE BOTTLE is TURNED COMPLETELY ""OFF"".
TURN the ignition key on,then swicth on the MASTER ARM SWITCH in the dash.
This supplies power to the ZEX CONTROL MODULE.
All of these INSRUCTIONS are included with the kits,
On the side of the CONTROL MODULE you will notice a BLACK BUTTON along with a GREEN and RED LED.
With the master switch and ignition switch on, PUSH the BLACK BUTTON in until the LED starts flashing,this notifies you that you are in PROGRAM MODE.
LEAVE THE THROTTLE C LOSED.
When the LED stops FLASHING the unit has loaded the CLOSED THROTTLE INPUT VOLTAGE,)normally below 1 volt).
The NEXT STEP is to INPUT the WOT voltage,
SIMPLY hold the throttle fully OPEN.
WAIT FOR THE LED TO STOP FLASHING,
THATS IT,SYSTEM INPUTS LEARNED.
NO ADJUSTING FIDDLY MICROSWITCHES ETC.
The control MODULE has a single NITROS OUTLET PORT which goes to the nitros fogger nozzle.
The SUGGESTED OPTIMUM POSITION for the ZEX FOGGER NOZZLE is APPROX. 6 INCHES (150mm) BEFORE the THROTTLE BODY.
The other outlet point on the control module is labelled FUEL.
THIS IS WHERE IT GETS INTERESTING and the FUEL ENRICHMENT SIDE of the system is explained.
The FUEL dedicated port is a HEAVY DUTY VACUUM HOSE which is plumbed into the FUEL PRESSURE REGULATOR.
On NITROS SYSTEMS (WET) you have both NITROS & FUEL being injected into the inlet tract, the extra fuel is normally supplied (on EFI SYSTEMS) from the fuel supply hose that feeds the fuel rail.
The N2O & FUEL MERGE TOGETHER AT THE FOGGER NOZZLE.
The ZEX SYSTEM APPLIES NITROS ::BOTTLE PRESSURE:: DIRECTLY TO THE FUEL PRESSURE REGULATOR.
This pressure acts against the diaphram causing fuel pressure to climb linear to bottle pressure giving you your fuel enrichment for the NITROS applied.
By doing this the CORRECT METERING of FUEL ENRICHMENT REQUIRED is APPLIED.
As the bottle EMPTIES the pressure drops, (IF NOT USING A BOTTLE BLANKET)
In a normal system set up,you still have the same amount of enrichment fuel supplied to the engine,but less NITROS,which causes over rich mixtures.
ZEX have this problem solved with their FUEL PRESSURE REGULATOR ENRICHMENT STRATEGY.
The MIXTURES REMAIN AS CLOSE TO CORRECT AS POSSIBLE IN RELATION TO BOTTLE PRESSURE.
When the NITROS ISN'T ACTIVE (switch on,WOT PRESENT) the fuel pressure regulator still functions normally,giving you normal state of tune and fuel economy.
THE NITROS JETS IN THE KIT REGULATE NITROS FLOW REQUIRED TO ACHIEVE THE PREDETERMINED HP LEVEL YOU CHOOSE.
THE FUEL JETS IN THE KIT REGULATE THE APPLIED NITROS PRESSURE TO THE FUEL PRESSURE REGULATOR,TO ACHIEVE CORRECT LEVEL OF ENRICHMENT.
100 HP SHOT OF GAS ""NORMALLY"" EQUATES TO A 1 SECOND DROP ON YOUR NON NITROS ASSISTED 1/4 MILE ET.
If your car runs eg: 12.5 sec @ 106mph,
With 100hp GAS ASSISTANCE you should see 11.5 sec @ 116,maybe 118 MPH.(APPROX)
NITROS OXIDE IS THE ULTIMATE INTERCOOLER.
I WILL COVER ALL ""BASIC"" SYSTEM OPERATIONS,SYSTEM REQUIREMENTS,NITROS TUNING TIPS,WATCH DOGS (SYSTEM GOVERNERS), ENGINE REQUIREMENTS,IGNITION RETARDS,SPARKPLUG HEAT RANGES ETC
BOTTLE PRESS. and its importance, BOTTLE BLANKETS as time permits.
PLUS ANSWER ANY QUESTIONS YOU PEOPLE MAY WISH TO ASK.
I HAVE USED ALOT OF THESE ZEX KITS,on 4cyl.turbos,6cyl.turbos,8cyl.supercharged, and a V8 B.M.W.
With excellent results.
You will need to retard your ignition timing 2 degrees for every 50 HP GAIN,
THEREFORE : IF YOU USE,
1. 50 HP JETTING - RETARD IGNITION TIMING 2 DEGREES.
2.100HP JETTING - RETARD IGNITION TIMING 4 DEGREES.
3.150HP JETTING - RETARD IGNITION TIMING 6 DEGREES
AND SO ON.
ON AN SR20DET, loosen the 3 x 10mm bolts on the CRANK ANGLE SENSOR,
Put the INDUCTIVE PICK UP of your timing light around the TIMING LOOP at the rear of the engine.
The TIMING LOOP is in the IGNITION MODULE LOOM.
Check IGNITION TIMING at IDLE,ENGINE at OPERATING TEMP,NO LOAD.
Your STATIC TIMING SHOULD BE 15 DEGREES.
Turn the crank angle sensor until you see the appropriate timing value corresponding to your power level.
EG: YOU CHOSE 100HP, you must retard the timing 4 DEGREES,
THEREFORE YOU MUST SET YOUR STATIC TIMING TO A VALUE OF 11 DEGREES,
If you dont have a DIAL BACK TYPE TIMING LIGHT, to achieve an accurate 11 degrees, set the timing to 10 degrees.

Edited by david kriedeman, 16 July 2006 - 05:38 AM.

[TTCV8]

Gee dave you must be pretty quick on your typing skills by now mate reading some of your detailed threads great info
Whats your thoughts on nos for my monaro stock LS1 capa powerdyne 5psi extractors twin 2 1/2 ex auto edit
Will this cause any probs over time as l would only use at tville so it wouldnt be used much maybe 6 to 8 times ayear?
Any info and advice would be appreciated
Cheers
Paul

[Graham]

wow what a post. thanks for that david. i wont be doing a wet system. what is the smallest nozzle you can get that works effectively? is the 75hp nozzle the smallest?

a question in regards to turbos. if per chance i were to have a turbo have i have "set" via a boost controller to a certain psi and it reaches a certain hp figure how would introducting the n20 make more power unless more pounds were setup?

i understand that it would get to boost quickier and if the turbo had more head room in regards to more available boost it would be able to reach that point.

i dont think i have made my self clear.lol

okay

200kw limited by the wastegate via a boost controller.
turbo can still do another 30kw but the boost is not turned up
how can the n20 give more power in the full boost "power band" so to speak considering that the turbo is limited by the boost controller?

[david kriedeman]

HI PAUL, your vehicle is a DIFFERENT KETTLE OF FISH ALLTOGETHER.
The LS1 GEN3 has a different (non conventional) FUEL SYSTEM.
If you look in the engine bay at your FUEL SYSTEM,you will notice that you DO NOT HAVE A FUEL PRESSURE REGULATOR.
On your vehicle and all LS1 GEN3 powered vehicles the FUEL PRESSURE REGULATOR is MOUNTED in the fuel tank.
THESE REGULATORS DO NOT HAVE VACUUM HOSES TO THEM FOR ANY TYPE OF VACUUM or BOOST REFERENCING.
The FUEL PRESSURE REGULATOR IS (like all fuel pressure regulators) A RESTRICTOR,MAKING A RESISTANCE TO FLOW WHICH CREATES PRESSURE.
The ECU GOVERNS the fuel pump OUTPUT to apply more CURRANT to the pump,this makes the fuel pump spin faster which CREATES MORE FLOW through the same REGULATOR RESISTANCE WHICH INTURN CAUSES THE PRESSURE TO CLIMB.
SO HOW WOULD YOU RUN A DRY ZEX SYSTEM ON YOUR VEHICLE.
SIMPLE YOU CANT.
EDELBROCK have a dry system available for LS1 GEN 3's, (BUT PERSONALLY I DONT LIKE THEM)
The reason for my DISLIKE is the FUEL ENRICHMENT CIRCUIT.
The ENRICHMENT CIRCUIT IS VERY CRUDE and INACCURATE in my opinion.
EDELBROCK,s SYSTEM uses a single FOGGER NOZZLE, however in this senario the FOGGER gets plumbed into the air box.
The MAF SENSOR is SOLELY responsible for the enrichment.
The MAF gets hit with the incoming NITROS charge, the sensing THERMISTOR goes "SHIT THIS AIR IS F#@KING COLD, I'd BEST RAMP THE FUEL CURVE UP ACCORDINGLY)
The problem with this set up is the MAF.
If you have read my other thread on MAP vs MAF you will understand where the issues lay.
If you havent read my thread, then a quick explanation is that MAF sensors are prone to contamination,which leads to INACCURATE FUEL and IGNITION STRATEGIES.
If you have a contaminated (DIRTY) MAF, YOU WILL RUN LEAN.
RUNNING YOUR or any ENGINE LEAN is not a desired thing, coupled with FORCED INDUCTION the LEAN OUT SENARIO is amplified,FORCED INDUCTION & N20 would create even GREATER RISK OF a LEAN OUT, if the MAF SENSOR was contaminated.
On GEN3's you can also configure the set ENGINE MANAGEMENT system to run MAFLESS,(without a MAF SENSOR)
This is ENABLED ONLY through FLASH TYPE TUNING, LS1 EDIT, VCM SUITE ETC.
So if you run MAFLESS, how would this system work, EASY it WONT.
THE ANSWER to all of these ISSUES is called a WET SYSTEM.
FUEL ENRICHMENT is supplied via the existing fuel supply hose to the fuel rail.
The FOGGER NOZZLE is a TWIN ENTRY type nozzle, 1 entry N2O, the other FUEL.
So the mixture of both NITROS and FUEL come from the same fogger nozzle.
Not sure if you have a VORTECH RISING RATE FUEL PRESSURE REGULATOR on your set up, supplied in the supercharger kit,when you had it fitted.
I dont know if they are part of a POWERDYNE KIT as i have ONLY ever fitted VORTECH SUPERCHARGERS to GEN3's
The VORTECH RISING RATE REGULATOR if fitted is NORMALLY ANODISED BLUE in color, but can also be BLACK or SILVER.
These REGULATORS are round in shape and approx. 100mm or so in diameter.
YOU CAN NOT USE THIS TYPE OF FUEL REGULATOR to run a ZEX DRY SHOT.
These REGULATORS are NORMALLY a 6:1 ratio configuration.
MEANING YOU GET 6PSI FUEL PRESSURE INCREASE for EVERY 1PSI of BOOST.
This type of REGULATOR will NOT give you a true LINEAR FUEL ENRICHMENT with BOOST & N20.
USE THE """"WET"""" SYSTEM ONLY.
As for your IGNITION RETARD REQUIRED, the timing value required can be changed via the EDITING SOFTWARE that is used to tune your vehicle now.
Not up to speed on any of the LS1 EDITING SOFTWARE PROGRAMS, so i dont know if they have provisions for more than one ENGINE MANAGEMENT TUNE STRATEGY (MORE THAN 1 TUNE MEMORY)
EG: STREET TYPE TUNE
NITROS TUNE
If not it doesnt really matter, just get LEIGH to PULL the REQUIRED AMOUNT OF TIMING from the TIMING TABLE.
ONCE AGAIN 2 DEGREES RETARD FOR EVERY 50 HP N2O GAIN USED.
Have the timing added back after you get back from the DRAGS ETC.
You will also require to go another HEAT RANGE COLDER in the SPARKPLUG DEPARTMENT.
You should have been given a set of colder plugs with the SUPERCHARGER KIT.
What ever their HEAT RANGE is GO 1 VALUE COLDER, IF RUNNING 50 - 100 SHOT.
I would recommend that you start with 50 - 75 hp jetting first.
Safe starting point.
Gives you a safe level of POWER INCREASE to let you get used to the different POWER FEELING and how the POWER COMES ON.
NITROS IS """""INSTANT"""" IN ITS EFFECT ON THE POWER OUTPUT.
As soon as the N20 is deployed you feel it there imediately.
GEN3 TORQUE + SUPERCHARGER + N2O =SMILES,WHEEL SPIN & GOOD TIMES.
The amount you say you will use the NITROS would not REALLY have a any SERIOUS degridation to the engine,as long as the the state of tune is monitored and you have no LEAN OUTS or DETONATION ISSUES (POOR QUALITY FUEL ,TIMING TO ADVANCED ETC)
GIVE IT A SHOT ( no PUN intended)
I THINK YOU WILL LIKE IT, ""ALOT""

[david kriedeman]

Excellent questions GRAHAM,
1. 50HP JETS are NORMALLY the smallest settings you get in MOST NITROS KITS.
The HP LEVEL in NITROS KITS is GOVERNED by the JET SIZE not the nozzle,in most cases.
EXCEPTIONS to the general rule are BIG HORSEPOWER KITS 200HP and higher,where a combination of jet size & fogger size are required for the extra volume in flow.
In relation to your question "How will N20 give more power unless more boost is used"
HOW NITROS WORKS:
N20 = 2 PARTS NITROGEN, 1 PART OXYGEN.
When NITROS OXIDE is HEATED above 900 deg. celcius it turns into OXYGEN.
This heating OCCURS DURING the COMBUSTION PROCESS.
An ENGINE is nothing more than an AIR PUMP.
The MORE AIR it can INGEST, along with the correct amount of FUEL MIXTURE the MORE HORSEPOWER it can make.
NITROS OXIDE is also incredibly COLD.
Cant remember the exact temp. been too long, from memory i think it's in the vecinity of around -180deg.celcius, DONT QUOTE ME ON THAT.(I'll check my books and confirm & post it at a later date).
ANYWAY it's F@#KING COLD.
This in itself acts as an intercooler, cooling the incoming air charge as well.
The GREATER THE AIR INGESTED by the engine ,The GREATER THE EXHAUST VOLUME(not sound volume either) VOLUME in relation to CAPACITY.
The INCREASE in EXHAUST GAS VOLUME due to the N20, is what causes the TURBOCHARGER to SPOOL UP quicker, hence coming on boost earlier, REDUCING OVERALL LAG)
So you can get a power increase using the same boost pressure because of the simple PHYSICS (and the CHEMISTRY) behind N20 and how it works.
REMOVE YOUR TURBOCHARGER altogether, you now have a complete pig to drive, turn on the HAPPY GAS and your away, your engine is making the extra HP from the N2O only.
NOT SUGGESTING YOU DO THIS, ONLY USING AS AN EXAMPLE.
In stating these facts something that now MAY become an ISSUE on TURBOCHARGED ENGINES,
TURBOS are driven by exhaust gas,with the extra exhaust gas flow generated by the N20 can cause BOOST SPIKING (OVERBOOST).
MAKE SURE YOU MONITOR BOOST PRESSURE WITH THE N2O ON, """IN ALL GEARS""" as the values will get HIGHER with each UPSHIFTED GEAR SELECTED,due to the extra load.
I STRONGLY RECOMMEND A GOOD QUALITY ELECTRONIC BOOST CONTROLLER.
THESE CONTROL THE BOOST FAR MORE ACURATELY THAN PNEUMATIC TYPE BLEED VALVES (T's),They are able to change the PULSE WIDTH to the boost control solenoid, dictating how much pressure to bleed to atmosphere or to the wastegate actuator, CLOSED LOOP IF YOU LIKE.
The APEXi AVCR is an excelent ELECTRONIC BOOST CONTROLLER as it has many functions & settings.
1 of the MOST USEFULL FUNCTIONS is the GEAR JUDGE.
This enables BOOST CONTROL SETTINGS in all GEARS.
NOT ONLY BEING ABLE TO HAVE DIFFERENT BOOST LEVELS for each gear, but also being able to CHANGE THE DUTY CYCLE (pulse width) for each gear.
On ELECTRONIC BOOST CONTROLLERS the HIGHER THE DUTY CYCLE, THE HARDER THE TURBO WILL COME ON BOOST,also the SPOOL UP WILL BECOME QUICKER
Once again spark curve has to be RETARDED.
SPARKPLUG HEAT RANGE MUS BE ADDRESSED.
I hope i have answered what you wanted to know.
If not or you want a more detailed description of something, let me know.

[Graham]

thankyou for you indepth reply. i liked readint the gen3 info aswell even though i dont have one.

as for my question. i understand pretty much all that you have said BUT. for no increase in boost presure how can it create more power when the wastegate is open? of course understanding that power will come quickier. the turbo wont put any more air into the cyclinders? am i right in thinking this? the turbo is the limiting factor when there is NO increase in boost??

thankyou
graham

[SiKnEsS]

i was thinking of goin my zex nitrous system on my lancer,, i only wanted a dry system and didnt want to run anymore than a 100hp shot, how much r the zex universal efi dry kit usually worth?? and who around cairns is the agent,, cause il be buying and fitting a nitrous kit this week,, but will be dissconected for e4 lol

[david kriedeman]

Hi GRAHAM,
you are looking too deep and missing the basic principles of the turbo charger.
The TURBO is still putting air into the cylinders even though the wastegate is open.
The wastegate is a BOOST CONTROL DEVICE.
It's 1 job in life is to CONTROL BOOST PRESSURE.
What you are thinking is CORRECT to a point, more boost = more horsepower.
I will explain what you wish to know a little differently with a bit more detail.
The wastegate opens and controls the boost pressure at a preset value,either the value of the wastegate actuator spring tension or the value set by your boost controller,whether it be pnuematic or electronic.
EG:
Lets say your engine/turbo configuration starts to make boost at 2500RPM,
Lets say your engine/turbo configuration reaches MAXIMUM boost at 5500RPM,
DEPENDING on the turbo & the engine specifications, your engine will still be making power above this 5500RPM mark.
YOU DONT SUDDENLY STOP MAKING POWER FROM YOUR ENGINE BECAUSE THE WASTEGATE IS OPEN.
Lets say you are running a GARRETT GT35R (35/40) 700HP TURBO.
You have your boost control device set at 20PSI.
You drive the car at full throttle,the turbo is starting to make boost at 2500rpm, you hit 20psi at 4000rpm because you are in 4th gear so the turbo reaches MAX.PRESET BOOST(you have chosen)due to the extra load of being in a taller gear.
AT 4000RPM YOU DONT suddenly run out of power because the wastegate is open, the AIR VOLUME your TURBOCHARGER is moving at 20psi is a CONSTANT, whether the wastegate is open or not.
The COMPRESSOR doing "X" amount of rpm,pushing "Y"CFM of air into your engine with the wastegate shut.
If the wastegate is open at 20psi, the COMPRESSOR WHEEL is still turning at the same rpm as if it were shut.
There is NO DIFFERENCE in SHAFT SPEED.
THEREFORE it is PUSHING the same AIR VOLUME into the engine.
The HORSEPOWER LIMITING FACTORS ARE:
1.ENGINES MECHANICAL INTEGRITY.
2.CAMSHAFT PROFILE (DURATION).
3.TURBOCHARGER DESIGN and SIZE,MAX.SHAFT SPEED,MAX.EFFICIENT BOOST etc (its overall EFFICIENCY) referring to TURBOCHARGER EFFICIENCY MAPS.
4.REV LIMITERS.
5. FUEL SYSTEM.
6.AIR CHARGE TEMPS.
7.WASTEGATE.
In saying all of this, what you have stated is sort of correct but not really.
Your engine reaches max boost in our example above at 20psi, the turbo in our example will support a constant 20psi all the way to your rev limiter.
If you were to put the vehicle on the dyno you would see the engine HORSEPOWER still climbing even though you are at max boost.
This is because the engine is still running,still capable of ingesting the constant CFM of air the turbocharger is pushing.
The engine will keep making horsepower until either you hit its max. efficiency revs or the rev limiter,(WITHOUT GETTING TO COMPLEX).
So whether the wastegate is OPEN or NOT, JUST REMEMBER THE FLOW RATE OF THE AIR CHARGE IS A CONSTANT VALUE (CFM) for the same amount of BOOST.
WASTEGATE SHUT,20PSI BOOST = "Y" CFM AIR VOLUME.
WASTEGATE OPEN,20PSI BOOST = "Y" CFM AIR VOLUME.
I CAN UNDERSTAND WHY THIS HAS YOU THINKING, BUT IT ""REALLY"" IS AS SIMPLE AS I HAVE EXPLAINED
If your turbocharger is the incorrect size for your engine (TOO SMALL) then you will see BOOST CREEP(boost pressure drop).
This can also cause horsepower drop.
But even in this situation you would NORMALLY still see horsepower climbing past the max.boost you have set,it just wont make as much horsepower.
REMEMBER how an engine works,
The wastegate is being held open controlling the boost,
NOT THE EXHAUST VALVES,
So the engine is still capable of making HP above its MAX.BOOST VALUE.
Add N2O and you make more power.
I HOPE THAT THIS HELPS, if not i dont mind you asking for more clarification.
I would like to know that you understand,
Regards DAVE.

Edited by david kriedeman, 17 July 2006 - 05:32 AM.

[david kriedeman]

Hi siklux,
The ZEX AGENT for AUSTRALIA is PERFORMANCE WHOLESALES in BRISBANE, ask for TIM.
TIM is the man resposible for ZEX down there.
There are many SUB-AGENTS but cheaper to buy DIRECT.
Tell TIM i said to ring him.
You are a mechanic so he should be able to do you a good price & should be able to sell to you.
If not let me know and i can set it up for you.
The ZEX DRY KIT for a four cylinder used to be around $990 retail from memory.
IF YOU CAN, MY ADVISE IS ALSO TO PURCHASE A BOTTLE WARMER,PURGE KIT and
BOTTLE PRESSURE GUAGE.
OTHER wise see JUSTIN or SHANE at NQ CRASH PARTS, they deal with PERFORMANCE
WHOLESALES.
Tell whom ever you order through you want a ZEX DRY SYSTEM to suit an EFI 4 CYLINDER.
Let me know if you have any dramas ordering or you need any help with the system set up.
Regards DAVE.

Edited by david kriedeman, 17 July 2006 - 05:22 AM.

[david kriedeman]

QUESTION for MR.SQUIGGLE,
can you enlighten me on "REMEMBER HALF THE NITROS DOSE WHEN RUNNING FORCED INDUCTION"
I have NEVER heard of this.
Was interested in why this is so.
I have set up plenty of FORCED INDUCTION,N20 ASSISTED COMBINATIONS WITHOUT ANY ISSUES, WITHOUT THIS HALFING THEORY.
Can you quiz your old man about it.
I think i used to buy stuff through your dad every now and again, did he own NITROS EXPRESS.
If so i still have a NEVER BEEN USED NX FOGGER EFI WET SYSTEM I PURCHASED FROM HIM ABOUT 5 YEARS AGO for a customers WRX,that he never got me to fit,which is for sale.
Regards DAVE.

[SiKnEsS]

thanks for the info dave,, i will contact performance wholesalers towards the end of this week,, il let u know if i have any problems,, cheers Dan

[mr-squiggle]

david kriedeman, on Jul 17 2006, 05:20 AM, said:

QUESTION for MR.SQUIGGLE,
can you enlighten me on "REMEMBER HALF THE NITROS DOSE WHEN RUNNING FORCED INDUCTION"
I have NEVER heard of this.
Was interested in why this is so.
I have set up plenty of FORCED INDUCTION,N20 ASSISTED COMBINATIONS WITHOUT ANY ISSUES, WITHOUT THIS HALFING THEORY.
Can you quiz your old man about it.
I think i used to buy stuff through your dad every now and again, did he own NITROS EXPRESS.
If so i still have a NEVER BEEN USED NX FOGGER EFI WET SYSTEM I PURCHASED FROM HIM ABOUT 5 YEARS AGO for a customers WRX,that he never got me to fit,which is for sale.
Regards DAVE.

yeh my old man used to be the aussie dealer for nitrous express, and for the forced induction, EVERYONE says that you should half the shot if you have forced induction, mabe i should ask the man that really knows lol, i will ask him tonight when he gets home from work

[ferret]

thanks dave. I will need to put a little more thaught into this before I go the wrong direction.

P I will be running 7psi for tuning and go up from there. I really wanna pull 10's but realistically low 12's would be good.

[david kriedeman]

Hi FERRET,
personally what i would be doing is sorting out what you already have.
Optimise all of your tuning,checking ignition curves,fuel system etc.
There is NORMALLY more power available from your existing package(THIS GOES FOR EVERYBODY) it just takes alot of thinking ,checking,adjusting to find your OPTIMUM setup.
It is easier if you have experience in this department, HOWEVER, dont be fooled into thinking it is any EASIER for us OLD FOLK who have 20,30 odd years experience.
Unless your setting up a COMBINATION you have done before and have already spent the time in R&D to reach this level of optimisation,it can literally consume HUNDREDS of hours to get every single HP out of your combo.
Once you have reached you OPTIMUM tune point, THEN throw a spanner in the works with a change to the combo like for example NITROS.
HAPPY OPTIMISING.
REGARDS DAVE.

[Graham]

thanks david. its is rather simple when you put it that way and i am questioning my thoughts as to why i thought the way i did in the first instance.