STI V5/6 heads revlimit
07 July 2008, 12:00 PM
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STI V5/6 heads revlimit
What is the revlimit on the STI V5/6 heads?
I set my limit to 7500, but heared that they normally rev to 8200rpm?!?
Would be great if I could use the rpm up to 8000 as my turbo would push enough air, no problem!
I set my limit to 7500, but heared that they normally rev to 8200rpm?!?
Would be great if I could use the rpm up to 8000 as my turbo would push enough air, no problem!
07 July 2008, 05:55 PM
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That´s good news, so the heads should flow enough air for a big power build with a revlimit of 8000, isn´t it?!
Would look for about 450-500bhp and the heads should be able to flow without failure up to 8k!
Would look for about 450-500bhp and the heads should be able to flow without failure up to 8k!
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09 July 2008, 07:35 PM
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That's what I was wondering, even though you can rev it to 8 grand, is there any power to be had on STi3/4 heads up there, or is it just headroom so you can drop back in at 6500 after an upchange?
09 July 2008, 08:21 PM
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No matter where the maximum power occurs, due to turbochange or other enginevitals you would reach this point even lower or higher in the revs.
Just need to know if the heads can take a maximum of 8000rpm with a big turbo, or if they are going to be stressed or damaged...
Just need to know if the heads can take a maximum of 8000rpm with a big turbo, or if they are going to be stressed or damaged...
09 July 2008, 09:25 PM
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No matter where the maximum power occurs, due to turbochange or other enginevitals you would reach this point even lower or higher in the revs.
Just need to know if the heads can take a maximum of 8000rpm with a big turbo, or if they are going to be stressed or damaged...
Just need to know if the heads can take a maximum of 8000rpm with a big turbo, or if they are going to be stressed or damaged...
Mick
10 July 2008, 10:00 AM
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Thanks for this information, too!
I would only rev to 8k on the dragstrip a couple of times a year, otherwise I wont push it that far anyways.
So hopefully they will be okay for some time!
Later on if they fail I might swap over to better valves and porting, too!
I would only rev to 8k on the dragstrip a couple of times a year, otherwise I wont push it that far anyways.
So hopefully they will be okay for some time!
Later on if they fail I might swap over to better valves and porting, too!
10 July 2008, 01:40 PM
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Thanks for this information, too!
I would only rev to 8k on the dragstrip a couple of times a year, otherwise I wont push it that far anyways.
So hopefully they will be okay for some time!
Later on if they fail I might swap over to better valves and porting, too!
I would only rev to 8k on the dragstrip a couple of times a year, otherwise I wont push it that far anyways.
So hopefully they will be okay for some time!
Later on if they fail I might swap over to better valves and porting, too!
Do you get involved in the streetcar cup or is that only the swiss guys?
Cheers
Steve
10 July 2008, 05:41 PM
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Hi Steve,
I do not drive at the Slalomcup, that´s too far away from Vienna!
But we have some Trackdays and other events too, but my first obsession is the quartermile that´s for sure!
Hopefully I can tell you good news after this weekend, until now my car did not work as it should due to boostproblems!
I do not drive at the Slalomcup, that´s too far away from Vienna!
But we have some Trackdays and other events too, but my first obsession is the quartermile that´s for sure!
Hopefully I can tell you good news after this weekend, until now my car did not work as it should due to boostproblems!
07 July 2009, 09:03 PM
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I am also very interested in this subject!
I have a forester sti with a forged 2.5 (with high 8.9:1 compresion)
And MD321t+ @1.6bar and getting 14mm head studs at the moment,
I'm using my standard AVCS sti heads,
As Above, As far as I know, they ae the same heads as the Ej20 which revs to 8,000rpm, SO I don't see how that is a problem,
Does power or torque output or high boost or the fact that she is a 2.5 have any negative affect on standard valves??
Really appreciate any feed back!
Thanks
Dan
I have a forester sti with a forged 2.5 (with high 8.9:1 compresion)
And MD321t+ @1.6bar and getting 14mm head studs at the moment,
I'm using my standard AVCS sti heads,
As Above, As far as I know, they ae the same heads as the Ej20 which revs to 8,000rpm, SO I don't see how that is a problem,
Does power or torque output or high boost or the fact that she is a 2.5 have any negative affect on standard valves??
Really appreciate any feed back!
Thanks
Dan
11 July 2009, 01:48 PM
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I am also very interested in this subject!
I have a forester sti with a forged 2.5 (with high 8.9:1 compresion)
And MD321t+ @1.6bar and getting 14mm head studs at the moment,
I'm using my standard AVCS sti heads,
As Above, As far as I know, they ae the same heads as the Ej20 which revs to 8,000rpm, SO I don't see how that is a problem,
Does power or torque output or high boost or the fact that she is a 2.5 have any negative affect on standard valves??
Really appreciate any feed back!
Thanks
Dan
I have a forester sti with a forged 2.5 (with high 8.9:1 compresion)
And MD321t+ @1.6bar and getting 14mm head studs at the moment,
I'm using my standard AVCS sti heads,
As Above, As far as I know, they ae the same heads as the Ej20 which revs to 8,000rpm, SO I don't see how that is a problem,
Does power or torque output or high boost or the fact that she is a 2.5 have any negative affect on standard valves??
Really appreciate any feed back!
Thanks
Dan
?Stu
13 July 2009, 02:13 AM
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Nothing but trouble to be honest! that's what I get for trying to be different!
The high compression coupled with the big boost on the big turbo seems to be lifting the heads (Panting) I think it's called, same symtoms as head gasket failure,I had 11mm apr studs before, and I'm going for 14mm WRC studs now to sort the problem!
In theory, she should be a very responsive torque monster, but she has never run right just yet! so far with heads lifting se made 415bhp @5800rpm, 450lb/ft @3550rpm but (seemingly) the ecu was pulling timing due to charge temps, the rolling road didn't have a fan for the top mount intercooler!
I'll hae her back together in the next few weeks,
I'll let you know how I get on!
If I was doing it again, I would defo go for standard CR with top mount and water/met for response! tried and tested,
Hope this helps
Dan
The high compression coupled with the big boost on the big turbo seems to be lifting the heads (Panting) I think it's called, same symtoms as head gasket failure,I had 11mm apr studs before, and I'm going for 14mm WRC studs now to sort the problem!
In theory, she should be a very responsive torque monster, but she has never run right just yet! so far with heads lifting se made 415bhp @5800rpm, 450lb/ft @3550rpm but (seemingly) the ecu was pulling timing due to charge temps, the rolling road didn't have a fan for the top mount intercooler!
I'll hae her back together in the next few weeks,
I'll let you know how I get on!
If I was doing it again, I would defo go for standard CR with top mount and water/met for response! tried and tested,
Hope this helps
Dan
Last edited by Forester sti; 13 July 2009 at 02:14 AM.
