VVC BHP differential

VVC BHP differential

Author
Discussion

ccconn

Original Poster:

36 posts

211 months

Friday 13th April 2007
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I am just about to pick up a 1.8 VVC with 150bhp
I see that the newer VVC engine outputs 160bhp
Can anyone tell me why this is so and is it easy to gain the extra 10 and more importantly will it be worth it?
Thanks

lukeb

89 posts

285 months

Saturday 14th April 2007
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I think the later VVC unit had the larger 52mm throttle body and allegedly a tweaked ECU. Maybe other changes too, I'm not sure.

I had an early VVC engine in my 7 and ended up tweaking it with the big TB, reprofiled exhaust cam, more fuel pressure all on top of a 4-2-1 exhaust. If I had to do it again I'd get the exhaust and leave it alone until I'd saved up for the 200bhp package of Emerald, fixed cams, individual TBs.

Edit to add: When I got the 4-2-1 exhaust the car made 164bhp on the rollers and felt fantastic, noticably more urgent than before. Recommended without reservation. The other work I did later, added just 8bhp and made the engine horribly peaky.

Edited by lukeb on Saturday 14th April 21:04

ccconn

Original Poster:

36 posts

211 months

Monday 16th April 2007
quotequote all
Thanks a lot
That sounds the way to go
Where do I get the exhasut and any idea of cost?

casbar

1,112 posts

222 months

Monday 16th April 2007
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4:2:1 around £800 from CC.

Once you have a decent exhaust, you need to get the car mapped, and probably get verniers fitted so the car cams are timed correctly. The standar cam timing is nearly always out.

When you have the car mapped, you will get true bhp, bhp claims of standard cars are sometimes off. My R300 engine made 162bhp after it had been mapped, it wasn't 160 before the mapping session. The fuel consumption and response was also greatly improved.

lukeb

89 posts

285 months

Monday 16th April 2007
quotequote all
As above, or you could go to someone like Powerspeed, Exhausts by design, Hayward & Scott for a bespoke system. I went for EBD as I had a Raceco silencer and wanted a manifold to mate it with.

I'm not sure casbar has grasped the implication of it being a VVC engine. You won't need to time the cams in because the timing is variable, and as long as you're running the standard Rover ECU there is unfortunately no mapping that can be done.

casbar

1,112 posts

222 months

Monday 16th April 2007
quotequote all
Yeh, missed the bit about it being a VVC. And if you do have the Rover ECU mapping is going to be difficult :0

So I'll just get back in my box

ccconn

Original Poster:

36 posts

211 months

Tuesday 17th April 2007
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So chaps does that mean if I change the exhaust I will get a benefit? even if I cant change the ECU?

ewenm

28,506 posts

252 months

Tuesday 17th April 2007
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A 4-2-1 exhaust will make a small difference. My car certainly felt a little sharper when I swapped to one. It's also transferable if you upgrade the engine to more powerful cams and an Emerald for example.

lukeb

89 posts

285 months

Tuesday 17th April 2007
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I guess YMMV to an extent, the difference in numbers is probably small but I was well impressed with mine. I'd registered & run around in my 7 for a few months using the standard short 4-1 and catalytic exhaust. When I upgraded to the 4-2-1 it felt like another step up in performance despite still being wowed by the zip of a 7. Bang for buck I couldn't fault it.

spannerman

118 posts

262 months

Saturday 21st April 2007
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The later vvc 160ish bhp has less shrouding around the valves and better valve seats thats about it

powderpuff

355 posts

256 months

Tuesday 24th April 2007
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The VVC 160 engine also has different pistons