putting a 960 TB on a N/A 850...

chef · Post by **chef** » 07 Mar 2009, 22:11

Hi guys, well i recently read a few posts talking about taking the throttle body plate from a 960 model and installing it into an 850 n/a car...the reason is that the two are the same size but the 960 one doesn't have the plastic piece on the inside flap as the 850 has. first off...why is the plastic piece there in the first place? secondly, does this "mod" do anything? does it help performance, gas consumption?? i hear the car is more peppy...any info would be great.thanks
fabs

Post by **tjts1** » 08 Mar 2009, 01:25

Its there to reduce throttle response. Makes the car easier to drive for old people or something. Most NA 850s sold in Europe didn't have it.

Craigd2599 · Post by **Craigd2599** » 08 Mar 2009, 06:25

It could be less for the safety of "old people" and more a function of the fact that the 960 is RWD. Perhaps the RWD setup requires a different approach. The biggest fucntional difference is the 960 is a six cylinder so the TB would have to be designed to flow more volume.

Post by **MadeInJapan** » 08 Mar 2009, 06:52

Increasing the throttle response is nice but remember that it will also decrease the MPG on your 850 N/A. I bought my N/A 850 to reduce the in-town gas usage over my S70 T5.

chef · Post by **chef** » 08 Mar 2009, 08:29

Hi guys..MIJ..why would it reduce MPG??? if it's flowing better shouldn't it use less???
TJTS1..didn't you do this mod on your car??? what are the current results?
thanks
fabs

Post by **MadeInJapan** » 08 Mar 2009, 09:08

Yes, current results would be nice!
To answer the question- better throttle response means more air (larger TB) and to compensate for that, more gas (adjusted by the computer), so over-all, nice effect but your MPG will suffer, at least in theory.

Post by **tjts1** » 08 Mar 2009, 15:53

Our 850 is a 5 speed manual. With the stock throttle plate, the car feels really sluggish compared to both my of my previous bmws. It took more than 1/4 throttle input just to get the car moving without stalling. Its much easier to drive quickly without the plastic chunk. Driving a stock vs modified TB plate car back to back is a night and day difference.
As far as fuel economy, I've done a lot of other small modifications at the same time to improve FE. I can't isolate the TB on its own. At 80mph the car does a consistent 30mpg, 70mph= 33mpg, 60mph = 39mpg on 87 octane. Our longest singe tank was 550 miles from middle of nowhere Oregon to Mill Valley, CA. I don't see how this modification will improve or hurt FE.

Post by **MadeInJapan** » 08 Mar 2009, 16:24

Okay...thanks for your input. I'm working on my '94 NA 850 in about a week. The TB is coming off for cleaning and to deal with a what I think is a clogged EGR system. That would be a good time to change up to the 960 TB. Is there any modification at all or do you just slap it in? Also, is the gasket the same as what you would use for an 850? I just bought parts including the 850 gasket.

Post by **tjts1** » 08 Mar 2009, 21:19

I think there is a little confusion as far as TB vs TB plate. The 960 throttle body won't work on an 850. The throttle linkage connects to the wrong side and the bolt pattern where it attaches to the manifold is different. But the 960 throttle plate has exactly the same 65mm diameter as the NA 850 throttle plate (turbos are 55mm). There are 2 screws holding the throttle plate to the throttle shaft. Once you have your 850 TB out, undo the 2 screws and remove the throttle plate from the throttle body. Then take the 960 throttle plate and install it into the 850 throttle body.

http://volvospeed.com/vs_forum/index.ph ... &p=1168946

I didn't have a new TB gasket to replace the old one so I just cleaned off the mating surfaces and applied a very thin layer of RTV. I'm not saying this is in any way better than the paper gasket but it works in a pinch. Let us know how you like it once you have the swap finished. I hope the difference isn't just in my head

good luck
Justin

Post by **MadeInJapan** » 08 Mar 2009, 21:39

Thanks for the clarification, Justin.
Is there no way to just cut the plastic piece off of the 850 throttle plate?