I cant rev more than 7200rpm now with my tomei 260x8.8 procams. Because the stock valvesprings do not work on higher rpm:s than that.
On the dynotest it clearly showed that after 7300rpm the valvs did not close and it lost all power very fast.
So wich ones to use? Id like to rev 8000rpm.
Wouldn't it be better to start with lighter retainers first? JUN makes them IIRC...
my car revs to 7500 and beyond with standard valve springs and its power is great up the top end.Originally Posted by Mobne
has to be said tho that i dont like it as i aint sure how safe it would be.
what a waste of time revving to 8k is. you'll much more likely find that what you're experiencing is heat build-up. what turbo are you using?
FYI I believe the CA uses the same spring rates as standard that Tomei specify for uprated SR springs, so they're pretty damn good already
could it be that he just hit the limiter?pretty conincidental that hwre he experienced massive power loss is where the std limiter is
I'm not a big ford fan but the RS500 is a legend, you cannot take away from it its Icon status and to suggest that its a chavvy car is like saying Kirsten Scott Thomas is a council estate slapper
Stock JDM CA revs to 7700rpm, stock valve springs should be fine for 8000rpm - I've read that 9000rpm is where the valves will start to float on stock cams and springs, you know what the internet is like though
Im amazed you feel the need with such modest cams.
I think you could spend the money more wisely elsewhere and also find that you are being restricted by something other than valvespring reactions. For what its worth we dont bother running more than 8000rpm on a full HKS Step 3 setup as the turbo is the limiting factor.
J.
Hi guys, i know what im talking about. I use the tomei 260cams and stock springs start to crap out after 7300rpm.
This is not a stock enginge
Runing haltech e8
With stock cams its a whole different story, but now i dont have stock cams.
I have a garrett gt3071r ar .86 making around 500bhp in my engine, and now there for need reving 8000rpm:s to be able to use my power.
So is the JUN springs good for 8500rpms? Or tomei spring kit? Wich one is recomennded?
Here you can se your self whats happening after 7300rpms when i get floating valves
Last edited by Mobne; 11-05-2007 at 17:59.
I've got ferrea VG30DETT dual springs and titanium retainers in my CA.
It hasn't been on the road yet though.
Where can i get those springs and retainers?
Because i can buy jun springs here in sweden for nice price and do you think this springs can handle 8000-8500rpm with no problem?
have you got a fueling graph for the same dyno run?
I imagine lots of places, I got mine from SPL in the states, but this gives you an idea of cost...
You need hte springs, the retainers and some special springs seats...
http://www.importperformanceparts.ne..._vsnissan.html
http://www.importperformanceparts.ne...retainers.html
http://www.importperformanceparts.ne...atlocator.html
Works out about $37 per valve.
Im on standard and I rev to 8200
Yes i do, i get it for you later
Last edited by Mobne; 11-05-2007 at 18:00.
I'm gonna be controversial now. That graph is incorrect the 2 curves don't cross in even almost the right place
It depends on how high the graph goes on the power side.
Heres a picture before and after tuning, just for you my friend
ah it's in NM, not sure where the crossing point should be for that, but the point at which the plots cross is NOT a variable. if it were in BHP and Ft.lbs they should ALWAYS cross at 5252rpm
that fuel graph gets very rich at the top, is the boost dropping off there?. I don't think valve springs are the source of your problem
The boost was not droping off. It can be to mych backpressure from the small exhaust housing, but i know more engines running sameturbo but stock cams and he revs 8000 no problem? But this problem only shows in the bench, on the streets it not so sure you notice this.
Turbo is gt3071r ar .86 wich is the biggest t25 flange housing avable.
Last edited by Mobne; 11-05-2007 at 18:32.
goes rich same rpm as the power dip
around what hp would the t25 footprint max out ?
what exhaust manifold ?
max boost ? + cams could be affecting valvesprings, whereas lesser setups rev 8k fine ?
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