F1 turbo era

[dubmeister]

Well known story!!! It's still a rumour but most likely to be true - the older blocks have tighter grain structure, and the theory also follows that the engine has had all the stresses beaten out of it already, so it's done all the "settling down" that it's ever likely to do.

There used to be adverts in the American magazines for mail-order engines that featured "seasoned" blocks - the same idea applied as per the BMW blocks for F1, just a little larger than 1500cc...

We use good second hand blocks in all the race/rally engines we build- less chance of stress failures when being caned!!

The trick that we used to do with the old cossie turbo rebuilds was to use an old "205" block from an old transit- cost pennies and was more reliable and a LOT cheaper than a "genuine" cossie block(when in reality they were all the same), but of course you then had customers who would still pay beserk money for a "200" block(escort cossie)

As long as the block is complete and serviceable they are far more reliable(and easier to run in than new or low milage blocks).

[Keeper of The Kitten]

I remember the amount of work we used to do to the Toyota 3SG engines for BTCC and F3 racing - although technically the homologated block was the Carina engine we used to use the Celica turbo block for various reasons.

The amount of fettling done on the inside surfaces to remove all the sharp edges/stress points was insane, and not a very pleasant task by all accounts!

But the inside of those blocks was soooooo smooth!

[dubmeister]

Take a look at these turbo F1 engines, The renault engine uses the DPV system created by jean pierre (french engineer), a form of antilag which uses variable nozzles to control the air into the compressor instead of a simple throttle plate that most of the other teams use.

http://www.gurneyflap.com/bmwturbof1engine.html

IIRC the throttle is located before the compressor and instead of a BOV (blow off valve), a POV (pop off valve) is used which vents any pressure over your desired boost pressure to atmosphere. With all airflow blocked to the compresssor blocked between gear changes the turbine/compressor shaft speed stays in the maximum efficiency area on your compressor map which gives instant throttle response. Apparently the renault drivers did`nt know what turbo lag was

Was thinking of trying this on my car as a little project.

Surely there are easier ways to control the lag nowadays with electronics- rather than a mechanical(and flow disturbing) method??
and anyway the normal antilag method of injecting fuel to keep the turbine spinning looks the absolute ********!!!!!

[gnutz2]

Surely there are easier ways to control the lag nowadays with electronics- rather than a mechanical(and flow disturbing) method??
and anyway the normal antilag method of injecting fuel to keep the turbine spinning looks the absolute ********!!!!!

I agree, i can flick a switch and have the ecu retard the ignition and over fuel by a pre determined amount which the DTA im running will quite happily do, and also open a solenoid to trigger an egr valve.

But how cool would it be to use the same technology the F1 cars used in that era, after all if its good enough for a 1000hp per litre its good enough for me. The idea mainly appeals because there`s no worry of high egt`s, unlike afterburn antilag which can very easily cook a turbo and manifold.

Obviously this system is not for of the line but its more about between the gears using the momentum of the turbine to keep its speed.

[20vQC]

Well is the same theory as used on supercharged cars! It should be used on turbocharged engines... I mean is almost the same thing as supechargers...there's a atmospheric inlet, the air is compressed and sent with over 1bar absolut pressure. Hey GNUTZ... if you do it, tell us how's it goes! If it works I'd like to do that too on my AAN.

Cheers!

[Puglife]

Peugeot used a VAT turbo on the T16 roadcars to aid boost. Was a T25 iirc.

The Garrett T25-VAT turbo has a variable turbine passage. This type of turbo was introduced on the 405 T16 in 1991. A movable tongue is mounted in the throat of the turbine housing. This stainless steel tongue is mounted on an axle and is able to maximally rotate 28 degrees. The position of the tongue is regulated by the influence of a pneumatic cylinder controlled by the electronic valve that is controlled by the motor management.

At low revs and/or load there is only a small passage between the movable tongue and the turbine housing. At high revs and/or load the passage gets larger. By doing so the available exhaust gasses always give maximal acceleration. Except for this system this turbo also has a normal waste-gate. This waste-gate also is actuated by a pneumatic cylinder controlled by the electronic valve that is controlled by the motor management. The combination of these two turbo regulations provides an optimal pressure filling. Under certain circumstances an increased turbo pressure can be obtained (1.3 bar instead of 1.1). This over-boost period lasts maximally 45 seconds but can be restarted 1/10 of a second after termination if all the required conditions are still there. These are:

1. Which gear is the car in. A sensor determines the transmission between car speed and engine rev. In 1st gear or reverse no extra boost is delivered.

2. The temperature of the inlet air after the inter-cooler may not exceed the 80 degrees Celsius.

3. Extra boost is only delivered when the throttle is actuated fully and quickly.

[diesel des]

Putting a throttle before the compressor will cause a vacume pulling the oil past the oil control seal in the turbo, into the inlet. Not a big problem in a f1 car that speeds 90% of its time at Wide Open Throttle, but on a road car that spends 20% at WOT.