quattrobros twincharged audi 90

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Re: quattrobros twincharged audi 90

Postby audifreakjim » Wed Jul 22, 2020 6:24 pm

Looking good! That odd area in your fuel map is due to oscillations in fuel lines caused by the injectors pulsing. Sometimes they can be eliminated by using softer rubber lines instead of hard lines.
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Re: quattrobros twincharged audi 90

Postby quattrobros » Wed Jul 22, 2020 7:24 pm

More bad video!

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Re: quattrobros twincharged audi 90

Postby quattrobros » Wed Jul 22, 2020 7:41 pm

Interesting. why only at that rpm? So as ethanol% is higher more fuel is needed and the pulses get larger causing that zone to be more pronounced? Maybe because my lines are still stock size too?

Ive also read that the lambda target table plays a role in those numbers as well. so a "100" VE at a target of 1.0 is not equivalent to "100" VE at a target of say 0.80. Meaning 130 in that zone is not as much fuel as i think it is compared to 115 at my WOT zones.

Could be wrong. Overall I'm not too worried about it anymore. Ive been told its not uncommon for VE to change as Ethanol % increases.
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Re: quattrobros twincharged audi 90

Postby audifreakjim » Thu Jul 23, 2020 10:45 am

VE of your engine doesn't change on ethanol, required fuel does. Just have to think about it a different way. For the fuel map, it is pretty normal to have a spot like that in most setups. Your injectors are not able to deliver as much fuel in that spot because of the reversions in the system. So you have to add VE to trick them into opening longer.
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Re: quattrobros twincharged audi 90

Postby quattrobros » Sun Aug 30, 2020 5:46 pm

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Re: quattrobros twincharged audi 90

Postby quattrobros » Sun Aug 30, 2020 5:47 pm

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Re: quattrobros twincharged audi 90

Postby quattrobros » Sun Aug 30, 2020 5:47 pm

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Re: quattrobros twincharged audi 90

Postby quattrobros » Sun Aug 30, 2020 5:50 pm

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Re: quattrobros twincharged audi 90

Postby quattrobros » Sun Aug 30, 2020 5:54 pm

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Re: quattrobros twincharged audi 90

Postby quattrobros » Sun Aug 30, 2020 6:01 pm

Currently at 25 psi. Stiffer wastegate spring on the way looking to do about 30psi soon hopefully :)

The jump from 20psi to 25 psi was insane. At least 50hp on the butt dyno.

My redline is at 7200 rpm. What do you guys think i can safely redline to? Head only has upgraded valve springs and a billet cam gear.
Last edited by quattrobros on Sun Aug 30, 2020 9:04 pm, edited 1 time in total.
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Re: quattrobros twincharged audi 90

Postby Lucky » Sun Aug 30, 2020 6:42 pm

The sounds coming from that thing are insane! I love it!!
1988 Audi 80 quattro, 2005 Ranger, 2006 BMW 330i, 1996 Yamaha Virago
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Re: quattrobros twincharged audi 90

Postby jolio1994 » Sun Aug 30, 2020 9:44 pm

This thing has all the right sauce!
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Re: quattrobros twincharged audi 90

Postby PRY4SNO » Sun Aug 30, 2020 9:47 pm

Seeing the 90q beside a modern car reminds me how much I love the proportions.

Great work so far!

Common wisdom states 8k as the upper limit, anything else is begging for a lifter or oil pump failure. Not sure of/if any impacts of the supercharging as I believe the oil pump issue is due to destructive harmonics.
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|| 2010 Golf Sportwagen TDI /// #farmenwagen
|| 2002 Dodge Ram 2500 24vt 4x4 #bertancummins
|| 1992 80 quattro 20v /// Eventual AAN'd Winter Sled
|| 1990 Coupe quattro /// Because Racecar
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Re: quattrobros twincharged audi 90

Postby quattrobros » Sun Aug 30, 2020 10:30 pm

Thanks yall!

That's what I've been hearing as well 8k. Ive never heard of the oil pump failure before.

The supercharger pulley is actually attached on the outside of the crank pulley so there is that rubber between the inside and outside portion still which worries me a bit. Everything feels smooth and at 8k the supercharger isn't being driven anyway. I did get the rotating assembly balanced when doing the build and i made sure it was done the right way too as prescribed by Jeff at FRP.

No strange vibrations so far but i guess that's not something you can really feel. Maybe high 7000s?
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Re: quattrobros twincharged audi 90

Postby PRY4SNO » Mon Aug 31, 2020 10:19 am

Ask Jeff and let us know what he recommends!
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|| 2010 Golf Sportwagen TDI /// #farmenwagen
|| 2002 Dodge Ram 2500 24vt 4x4 #bertancummins
|| 1992 80 quattro 20v /// Eventual AAN'd Winter Sled
|| 1990 Coupe quattro /// Because Racecar
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