B B C 5 4 0 T W I N T U R B O Q U E S T I O N S

[hannes_slanec]

Hello, I would need some help with my 68 Impala with 540BBC twin turbo project I hopefully will introduce in the project thread soon.

How can give me some hints what leight and not tooo expensive turbo is the right one (trim, A/R, housing, size and so on...)

The turbo shall make not more than 6-9PSI of boost and not earlier than from around 3500-4000rpm (Redline is 7000rpm).

My expected HP rating is around 1000HP, I would like to reach a 3,5sec 0-60 time.

My compression is not that low with 9,2-9,5:1 (depends on the head gasket I will go with) but that car needs to be streetable and therefor the mileage is important.

7 or 8:1 would make the mileage suffering.

Also a nice cam advise would be appreciated, the car will go with a modified Vortec 7400 EFI.




Thanks in advance

Hannes Slanec

[bentfab]

Contact Tom Nelson he is the twin turbo mad man. Or go to his web site: www.nelsonracingengines.com
He's a site sponsor

[hannes_slanec]

Thanks for the hint but I fear he will not have the time to help someone who cannot afford to buy an engine from him.

I live in Austria, the transport and tax alone would cost more than the engien itself (we have tax up to 65%).

Thanks Hannes

[Payton King]

540 ci BBC twin turbo and gas mileage are mutually exclusive.

[hannes_slanec]

I knew that that statement will come as it comes always from somebody but it is a difference if I need 20 liters of gas per 100km or 45 liters .

There is no need to talk about any further, any engine got a fuel consuption range from / unitl, it depends on many factors what the mileage is finally.

An carbureted, hot camed, low static comp. engine with a high stall speed, 4.88 gears and a food that is down on the floor most of the time will need more than a fuel injected, properly tuned, mild camed, high comp. engine with a low stall speed, 3.08 gears and a driver who push the padel once in a while, even if they got the same displacement.

And I just want to be on the lower side of the range of an 540cid engines fuel consumption.


Hannes

[TOM NELSON]

A mid frame 88mm i would probally use that way it's not coming on boost to fast.And will be better on mileage The 88 will be able to make the 1000hp you looking for.You can find them rebuilt pretty cheap i'm not sure of the supplier but ive seen them for as little as 700.00 rebuilt.Hope that helps