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Pontiac - Boost Turbo, supercharged, Nitrous, EFI & other Power Adders discussed here. |
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#21
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The Fi Tech and holley super sniper work well with boost. I am leaning towards one of those sets ups. Can't beat them for the money. I like the holley since you can use there program on a laptop. Steve Morris sets them up for your specific engine and sells them to you also. Good idea to leave room to grow. |
#22
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__________________
1978 Trans Am Pump Gas 461 Stroker |
#23
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Or, perhaps, they like to have the exhaust valve open sooner.
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'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'. '67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust |
#24
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Yes it is a combo of things, also helps spool
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#25
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One thing to take into account with the Holley Sniper systems is that they can run only a maximum of around 16 psi of boost, ok if you have a well built big engine with very good heads-but not much good if you have a smaller engine with average heads. I had this discussion with Steve Morris as I had intended using a Sniper 4500 unit on my 400 combo at 25 psi of boost, he said it will only accurately meter fuel to 16 psi boost, above that and you're off the fuel map,running on a wing and a prayer effectively.
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#26
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https://www.holley.com/products/fuel.../parts/550-512 Look at the spec sheet |
#27
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I know someone running the FI Tech 25 psi no issue
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#28
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I can only say what Steve Morris told me, these were his words- 'Hey Pual,
I noticed going over your engine info that your running 25PSI of boost. That's going to be a bit high. The MAP sensor in the sniper is totally fine to use but typically you start running out of injector around 16PSI. At 25 you will most definitely starve it for fuel. And after I questioned this (why would the system have a 2.5 bar MAP sensor if that is the case? And why do Holley say that an external 3 bar MAP sensor can be used if the system can't run enough fuel for that boost pressure?) ,his reply - 'So the sniper software has a fuel map for volumetric efficiency and flow rate. These 2 fuel maps max out at 16 psi. So beyond that the sniper is running into an un-mapped area so it will be relying off of the last mapped number on the graph and the o2 sensors to try and correct it regardless of boost level. Its not the most ideal place to run it. |
#29
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#30
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I called FI Tech a couple of years ago about the 1200 PA series. I told them I would like to make 1200+ with it. The tech told me that I will be lucky to get 1000 hp out of it and that is on gas. He said that the 1200 rating was on NA setup. But now I see that they changed their ratings. I'm running an E85 BT carb when I got my engine dyno.
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#31
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Just to add, there are people over on the "Fitech Owners Group" Facebook page and "Fitech EFI Users" Facebook page that have had success increasing the injectors size so they will support more power as well.
__________________
1978 Trans Am Pump Gas 461 Stroker |
#32
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Both FI and Holley are exaggerating the power capabilities of these power adder systems, neither have enough injector capacity to make 1200hp, I've checked quite a few injector calculators and even entering a very low bsfc of .50 (usually n/a combos) and a very high 95% duty cycle-these systems still fall short. It's a shame ,because the Stealth 4500 (Domi style) system would make a great blow through turbo combo if it could produce more power -say around 1500hp - as it has built in datalogging,traction control, ignition control,afr/boost/temp safety settings etc, and no complicated wiring set up either. Introducing the fuel higher up in the intake is also beneficial to charge cooling and more power than comparable port injection IMO.
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#33
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__________________
1978 Trans Am Pump Gas 461 Stroker |
#34
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To support an honest 1200 horsepower, it would take (8) 88lb injectors at 43.5 psi, so at 58 psi that the Fitech runs at, you could probably squeeze by with (8) 82lb injectors.
__________________
1978 Trans Am Pump Gas 461 Stroker |
#35
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Not sure about that deal, TransAm 474.
Years ago several racers were going from 43 psi to 68 psi and only picking up a couple of lbs/hr mass flow thru the injector. The injectors were set for 85% Duty Cycle. Once you get over 85% Duty Cycle on an injector you are playing Russian Roulette with the Injector Flow Rates. People who try to run in the low 90s need to spend their money on better flowing injectors vs possibly destroying engine parts, (that wasted money could have been used to buy several sets of higher flow injectors). Tom V.
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
#36
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They have 100lb injectors in the holley already I thought.
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#37
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My calc says 1200hp would need 8 x 116lb injectors at 43 psi fuel pressure with bsfc at .65 and inj. duty at 85%.
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#38
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Quote:
Tom V.
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
#39
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I be in this section in a few more months I am going to try and get a turbo motor built. I notice that fast has 220lbs injectors they say these injector can handle 3500 HP.
https://www.fuelairspark.com/8-fastt...-injector.html |
#40
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I definitely would agree with yall, since I'm not an expert at this... I was just going by this calculator, but it very well may be incorrect
https://www.google.com/url?sa=t&sour...jMQt5H9phj-knZ
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1978 Trans Am Pump Gas 461 Stroker |
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