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1988 Mustang GT Intake Swap

974 Views 10 Replies 3 Participants Last post by  need4spd90
Ok soo i am done with my pp typhoon intake it has caused me nothing but headace since i built my motor so i was wondering what other would recomend when it comes to a new intake for my set-up im running the 5.0 block with gt40p heads, ford racing "B" cam, 24 lb injectors, 70mm tb and egr spacer, 73 mm pro m meter with cai, ford racing headers, 3.73 gears, sct 4 bank chip,under drive pulleys, electric fan, short belt (smog pump deleted) and just for refrence my cars a 5 spd.
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A simple gt40 intake would be sufficient for that build. If want room to grow then get a Holley or TFS street
Thanks! i was looking at the holley they seem nice
im leaning towards the holley systemax it looks nice and has gotten good reviews will that lower bolt right up to my gt40p's?
yeah the holley will work with p heads
thanks man everyone on here has been helpfull and chill this site is awsome
i ended up taking advantage of the cjponyparts deal and went with a nice polished cobra intake new bbk adj fuel pressure reg 1/2 spacer and new hard coolant tubes. im intrested to see how this intake does with my setup anything has to be better than that leaky pos i have on there now.
well..hopefully you wont have any issues with it..some have been known to suck oil thru the pcv valve,and othser have had distributor clearance problems while trying to set the timing..tfi module hits off the t-stat housing

you also may want to take a grinder to clean up the runners,they've been known for having rough castings as know--made in china

but otherwise,the gt40 style intakes work well with a combo like that
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yea the castings were sooooo rough on that typhoon intake ill let you know how i make out. Not to get to off topic but any suggestions on were i should set my fuel pressure? my buddy is saying up around 40psi will prob do it what do you guys think?
stock is ~39.5 with the vac on the regulator unplugged..adding more pressure wont help much..if at all..39-40 will be fine
joel5.0 said:
Myth Case #4: Increasing FP will Raise HP Mythology Case #4:
Increasing fuel pressure will raise HP

Fact #4:
The amount of fuel added to the engine is calculated by the system based on engine conditions, and the feedback from the sensors in the system, including the O2's. A/F target is 14.64:1 and the ECM will make adjustments to the Injector Pulse Width (IPW) to reach the A/F stoichiometry goal.

EEC-IV tables are used for the calculations for IPW, including adaptive strategy learned for open loop and close loop operation, the only difference is, that once the system achieves close loop state, adaptive tables are updated....they are used under open loop, but not turning adaptive strategy off.

Fuel pressure setting does have an effect in the system since the amount of fuel will vary at the same IPW, the higher the pressure, more fuel is delivered at the same IPW setting....the system will get the feedback of this condition (O2 readings), and will trigger an IPW re-calc (shorten it) to reach A/F goal, thus cancelling the effect of a higher pressure setting at a point. However, fuel pressure setting IS important, since....

The adaptive system has a range of roughly +/- 25%. If you had an adjustable fuel pressure regulator installed, and you needed more fuel, you could keep cranking it up until the EEC could no longer dial the fuel back out.

......and confirmed in EEC-IV setups with the datastream capabilities, watching "fuel trim" parameter while causing (or troubleshooting) extremely rich/lean conditions.

Fuel pressure setting has a "centering" effect of the ECM fuel trimming capabilites or limitations....EEC-IV has the capability of doing short and long term "fuel trims" within a 25% (+ or -) of its internal fuel tables. This means that it can either increase or decrease fuel trim given the real time conditions (short term) and the new center fuel trim (long term or adaptive learned).

Let's use an example.......if long term fuel trim is "learned" and set at +15% by the system, and you suddenly get a vacuum leak that requires a 13% fuel trim "addition", the system will be uncapable of compensating for it and lean codes will show up.....on the other hand,......... if you have the long term fuel trim at -5%, ......the system will compensate for the time the condition is present, w/out the lean codes showing up, since the correction trim required is within its pulse width compensation range limitation.

Keep in mind, that the system will continue to update long term trim, and raise its value (in close loop), ....if the vacuum leak is permanent, long term will reposition to +8% with time....leaving less "room" to add fuel when required due to..........other conditions.

How to ensure fuel pressure increase is in control for richer WOT runs?.....old EFI school trick for drag racing....increase fuel pressure, disconnect O2 sensors to force open loop and prevent adaptive strategy from updating tables, clear Keep Alive Memory (KAM) and adaptive strategy're set until O2's are reconnected and O2 codes cleared.
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