Direct chassis engine mounting F1,F50,F60 etc.

Direct chassis engine mounting F1,F50,F60 etc.

Author
Discussion

PiB

Original Poster:

1,199 posts

277 months

Friday 5th December 2003
quotequote all
Why do people mount the engine directly onto the chassis without rubber bushings?

Is it mainly necessary when you have inboard suspension mountings on the transmission?

I was looking at this fine car on ebay

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2442836595&category=6737

...and thinking about how Ultima GTR's don't do this and how on the Carrera Gt they didn't use a directly mounted engine either but Ferrari does and so does the Mac F1.

350matt

3,766 posts

286 months

Sunday 7th December 2003
quotequote all
The main reason is because the chassis is bolted to the engine and the gearbox is also bolted directly to the engine and the suspension then bolted to the gearbox. Any rubber bushing introduces slack into the chassis assembly and reduces the performance of the suspension.
No rubber means nice and direct along with a lot of NVH but then it is a race car ....


Matt

danhay

7,467 posts

263 months

Sunday 7th December 2003
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If it's directly bolted to the chassis it can add to it's strength and stiffness. Once you add rubber bushes you lose that extra stiffness because the rubber just gives.

The reason most road cars don't have it is for NVH reasons as stated above.

The Honda CBR1100XX has it's engine directly bolted to the frame, but it's got balancer shafts to smooth out vibrations and stop your hands going numb!

stevieturbo

17,519 posts

254 months

Tuesday 9th December 2003
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I hve my engine and box bolted solidly into my car ( Rover v8 in Granada ) and its actualy very smooth. You wouldnt really notice it, but the car does feel better when driving.
Engine/box doesnt wallow about on soft rubber at every gearchange etc Less clunks, and a more positive feel.
Its also bloody cheaper than buying expensive hard rubber mounts. a bit of steel bar was free, plus the time it took me to make the mounts from the bar..

Worth a try. If you dont like it, you can always go back.

>> Edited by stevieturbo on Tuesday 9th December 01:06

Apache

39,731 posts

291 months

Tuesday 9th December 2003
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Weight? if the engine, gearbox and driveline become a part of the chassis?

stevieturbo

17,519 posts

254 months

Tuesday 9th December 2003
quotequote all
weight??? is that a statement, or a question ?

Apache

39,731 posts

291 months

Tuesday 9th December 2003
quotequote all
An answer to PiBs question. Weight might be a reason for doing this, or the saving thereof, but on reading the question again I realise I was talking bollox (again)

>> Edited by Apache on Tuesday 9th December 21:31