4.5 injectors ....what will they support?
4.5 injectors ....what will they support?
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Discussion

a1rak

Original Poster:

556 posts

213 months

Wednesday 10th June 2009
quotequote all
Does anybody know for sure what the maximum BHP the standard Injectors will support on a 2001 4.5AJP before the mixture starts to lean out....will they support 475BHP.

itsallyellow

3,879 posts

250 months

Wednesday 10th June 2009
quotequote all
Well they seem to be ok on mine so i would have thought so.

However i definatly feel they are approaching there limit.

Mike

spitfire4v8

4,025 posts

211 months

Wednesday 10th June 2009
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You're still on stock fuel pressure Mike too, so well in excess of 500hp if you're going up on pressure a bit aswell.

itsallyellow

3,879 posts

250 months

Wednesday 10th June 2009
quotequote all
So there is no point in going for new injectors???

spitfire4v8

4,025 posts

211 months

Wednesday 10th June 2009
quotequote all
well i would say buy them if you have to, not if you think you might need them. the exchange rate at the moment means theyre damned expensive.

Brummmie

5,284 posts

251 months

Wednesday 10th June 2009
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itsallyellow said:
Well they seem to be ok on mine so i would have thought so.

However i definatly feel they are approaching there limit.

Mike
Did you not look when they were on the rollers? You would have been able to see if they were approaching 100%. As said here you could up the fuel pressure but then you will have to re map to suit, as you would richen the whole map.

fatjon

2,299 posts

243 months

Wednesday 10th June 2009
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I got some siemens Dekra 640cc ones from the US for about $58 each plus about 15% import tax. I think it was about £250 in total for 8 when the exchnage rate was about 2:1, so a bit more now. Still much cheaper than in the UK though.

What's the part number of the originals, I have a chart with the specs for loads of injectors so I might be able to look them up, then it's just a simple calculation based on the flow rate and BSFC for the BHP limit.

Jon

a1rak

Original Poster:

556 posts

213 months

Wednesday 10th June 2009
quotequote all
got a call from Paul at Austec, I think he does all their MBE chip tuning.
He informed me that the standard injectors are capable of 475bhp but reaching their limit at 500bhp. Seems like I will not have to change the injectors then biggrin