Blow injector channel when bouncing off the rev limiter hard

[GintsK]

dont use igbt from vems shop on fet place, becouse fets are driven with 12-14V and maximum source-gate voltage for igbt is 10V.

I suppose it is about 10V continuous voltage. Seems gate is protected from overvoltage. Internal protection elements generates heat if input voltage is higher.

I suggest VNP5N07. It is protected from almost all kinds of troubles...

[dnb]

The webshop IGBTs are fine for this (I had some spare, so I used them and know that they work), but there are better things available if you are buying new items.

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These are the VNP5N07 FETs that Gints suggested:
http://uk.farnell.com/stmicroelectronics/vnp5n07-e/mosfet-smart-switch-to-220/dp/9804501?Ntt=VNP5N07
At £1.72 each you may as well get 12 - 8 of them to replace your injecter FETs, and four to fill the empty spaces in the ignition side of the board - as your P259 blew up you might want the extra channels to drive Fans, Fuel pumps and what have you...
There are ten FETs on the board, make sure that your mate only replaces the Injector FETs, and not the ones that go to the 18pin plug, as one of them drives the wideband and thats best left alone:
http://www.vems.co.uk/VEMS/WideBandO2.html

[GintsK]

For IGBTs or smartfets or IRF640 (except IRF640FP) insulator sheet is necessary between enclosure and metallic pad.
All three has same pin arrangement as original FETs.

[tom70]

Ok... I will order 12x VNP5N07 as suggested. Thanks.

Will these new FET affect my MAP much? As in different opening and closing injection characteristic.

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I would not expect any speed difference to be enough to change the fuelling.

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You might want to play safe and get some of these:
http://uk.farnell.com/laird-technologies/ther-t-small/thermaflex-tube-to-220/dp/547566

[tom70]

Ok. I have the chips and insulator with me now. I will bring it to the track, just in case.

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Well that's some hardcore race spares you're taking there.
Just don't forget the soldering tools, I had to re-solder a fuse on a car in the pits at Donnington with some bashed and well used Soldering iron courtesy of Driftworks' toolbox.

[tom70]

hmm.. just got back from the race. The engine just die after the first lap of practice and can't get it restarted until i reload the same map saved from my laptop.

Then, i had good 5 lap of hardcore hard reving in the following practice session. The engine was nice and strong.

but the no.4 cylinder FET decide to give up during the warm up of the qualifying session. not a happy bunny.

will swap all the inj fet next week

[Sprocket]

dont use igbt from vems shop on fet place, becouse fets are driven with 12-14V and maximum source-gate voltage for igbt is 10V.

Put irf640n and 1uF condensator and check flyback wire.

I have ran all IGTBs on all injector channels for over a year without problem, infact it was the only way I could stop smoking the FETs. I was advised to do so by the developers, in my case.

[GintsK]

Sprocket, it isn't the only way indeed. And not most correct way also because recommended gate voltage exceeded at each injector pulse.

[Sprocket]

Fair enough, maybe its a matter of time before they fail, but so far I have had more success with the IGTBs up to 8000rpm which was better than 1200rpm and 30 seconds I am also not suggesting that it is the only fix

On second look at the datasheet, it states gate voltage of 12v pulsed and 10v continuous.

[GintsK]

Most probably it will never fail. Ignition IGBTs has internal protection for gates.

[MWfire]

but driving resistor can fail at big duty cyles if you have strange alternator(more than 14.4V).