Someone told me that be changing the Volvo 850 2.3T camshaft to the Volvo 850 GLT 2.5 20V N.A camshaft will improve it performance.

Anyone have try that and please advsie.

 

Camshaft is one of the last things you change, after all the other stuff is done to it. If you have a n/a car, sell it and buy a turbo car.

 

agree with tryingbe, its a long way to get some minor change. Cams vary by lift height (how far the valves open) and duration (degrees of rotation) the valves are open). the bigger and longer the opening the more air gets in/out of the combustion chamber - which aids breathing at high RPM but hurts it at low RPMs. When I replaced a factory 270 degree cam on a BMW with a 300 degree cam (many years ago...) , I only noticed performance gains above 3500 RPM and a lumpier idle and lag below 2000 and I'd guess about a 10 HP gain on a 2.0L NA engine. With all this said, turbo cams typically have smaller lift and shorter durations vs NA cams to improve low end torque and to allow the turbo's forced air to produce the high end power. So the swap may give you a better torque under say 2500 RPM but less top end - good if you want a tractor motor...

 

I am having a beautiful Volvo 850 with 239hp.
Thanks for the advise.
Also read of change the n.a throttle body into the T5. N.A throttle body is bigger than the stock T5 throttle body. Any experience on it? If I have done above, will ECU upgrade with no performance as be designed mapping.
Which ECU is the best reliable and does not overloaded the engine no cause damaged?

 

There should be some posts on the throttle body swap out. As far as the ECU goes, its all about the mapping program installed in the PROM chip (programmable read only memory) aka a "flash chip". Many vendors support taking the factory ECU and rewrite the mapping program to allow for more boost at different RPMs. I think the easiest thing to do would be to buy a used ECU and then have that flashed to a new program keeping the second as a spare or for easy plug in at emissions time. Note some more aggressive programs can set off O2 sensor CELs so consider dropping in a CELBOSS or similar spacer which pulls the sensor out of direct exhaust stream. Different vendors have programs set by "stage" which assumes what other upgrades are in the car - ie bigger downpipe, bigger injectors, bigger turbo etc. If you plan on keeping your 15G turbo then go with a conservative stage 1. If you plan on upgrading to a 16 or 18 turbo, then you should follow a blueprint for add ons. Plenty of vendors offer ECU flashes for the 850s - and my personal opinion is they all tend to have the same programs.

 

Waste of time to go to the 3 inch n/a throttle body when the smallest part of the stock intercooler inlet is 2 inch in diameter. Your stock 2.5 inch throttle body will do just fine.

Now, if you have a do88 intercooler, then upgrading to a 3 inch throttle body would make sense.