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Location:
cronulla
Registered:
September 2002
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effect of running forced induction with standard ecu on VVT motor
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Sat, 15 January 2005 21:05
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does anyone know if running low boost, say 6 psi will work ok with a vvt motor running a standard ecu?
cheers
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Location:
S.E suberbs, Vic
Registered:
December 2003
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Re: effect of running forced induction with standard ecu on VVT motor
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Sat, 15 January 2005 21:09
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well you would need a rising rate fuel pressure regulator for a start, from there I wouldn't have a clue.
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Location:
Wollongong
Registered:
November 2004
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Re: effect of running forced induction with standard ecu on VVT motor
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Sun, 16 January 2005 00:56
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| Sam_Q wrote on Sun, 16 January 2005 08:09 |
well you would need a rising rate fuel pressure regulator for a start, from there I wouldn't have a clue.
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Yes you will need a rising rate fuel regulator...
But if you are smart... You'd get a programmable ECU...
As for with VVT... I suppose it can be done as the 2JZ-GTE has a VVTi version out...
But I know the Honda VTECs are useless for turboing...
As for 6Psi on stock internals... Whats your CR?
I've seen a 4G15 engine last around 60 000KM before having all the pistons just disintegrate...
If you want a reliable turbo... Rebuild the engine...
If you want a hand grenade... Turbo the stock engine...
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Location:
S.E suberbs, Vic
Registered:
December 2003
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Re: effect of running forced induction with standard ecu on VVT motor
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Sun, 16 January 2005 06:05
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I have to disagree with you on a few things Kyosho,
yes a programable ecu would be the way to go but thats not what he asked about.
Also I think often a stardard internals engine can handle some boost if it is tuned well. I bet that 4G15 pinged, or had an oil problem.
Also I have seen a Honda that was running sub 10s with standard camshafts in it. Ask the yeanks what they think about hondas and turbos, they love them both.
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Location:
Wollongong
Registered:
November 2004
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Re: effect of running forced induction with standard ecu on VVT motor
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Sun, 16 January 2005 09:41
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| Sam_Q wrote on Sun, 16 January 2005 17:05 |
I have to disagree with you on a few things Kyosho,
yes a programable ecu would be the way to go but thats not what he asked about.
Also I think often a stardard internals engine can handle some boost if it is tuned well. I bet that 4G15 pinged, or had an oil problem.
Also I have seen a Honda that was running sub 10s with standard camshafts in it. Ask the yeanks what they think about hondas and turbos, they love them both.
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The 4G15 did not ping, nor did it have an oil leak.
A rising rate fuel reg is not really sufficient... You will generally get a lean spot, followed by a rich spot, or vica versa...
A rising rate reg is VERY hard to tune by on its own.
As for your honda running sub 10s...
Lots of Hondas that are out, ARE NOT VTEC, some of the best Cams for Forced induction, are fuel conservative, N/A cams...
Huge N/A cams are useless, too much overlap and you start to blow everything out of the exhaust...
So your Honda you seen running low 10s, it may of been a normal cam, (Non-vtec) and hence, would of been quite good, as it is built to rev, and not have too high of an overlap
As for my recommendation on the ECU, that was pure guidance...
I wouldn't want to be trying to run a stock engine on boost at all as they are not designed for it...
The 4G15 managed to blow it self apart on 5Psi...
On another note...
Turbo engines, when on boost run in the 12s for AFR, a stock ECU is programmed to tune back to 14.7 (By way of the O2 sensor)
When you start to lean out past 13.5, you come into problems with the fuel burning too hot, and that is when rings and tops of pistons start to disintegrate...
So to avoid this, you will need to tune with the O2 sensor disconnected, and then you will encounter days where it will be a bit rich, and others it will be lean. Just like an old carby motor...
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: effect of running forced induction with standard ecu on VVT motor
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Sun, 16 January 2005 10:27
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I'll come to the rescue of Sam_Q here, I've read about multiple turbo Hondas in the states, and the majority of them still had VTEC.
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Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
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Re: effect of running forced induction with standard ecu on VVT motor
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Sun, 16 January 2005 21:15
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jaze,
to answer your question CONCISELY, no you can't.
My reasons why you can't lie in the fact that you wish to retain the factory engine management. With an N/A engine management system, the tuning and fuel maps only go marginally above air pressure at sea level, as it is near impossible to obtain a higher manifold absolute pressue.
Furthermore, if the engine uses a MAP sensor to measure engine load, then it will most likely be ~1.1bar absolute - meaning that the ECU will fuel cut at anything above atmospheric pressure, as the MAP sensor will give its max output of 5.05V (fuel cut is approx 4.95-5.05V).
With an aftermarket ecu, or even with an interceptor like an Emanage (with add-on MAP sensor) will allow you to modify the fuel maps enough to tune up to that manifold pressure... but a stand alone is a much better idea.
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