[SPIKE ARRESTOR]

Originally Posted by sapl

The strengthening was done to the rotating assembly. The most important of these being forged connecting rods. I have not taken any pics of the engine internals, will do so if we dismantle the engine sometime. Anything else done for lubrication etc?

The power limit was decided on the basis of a number of factors - sustainable boost levels over the entire rally course, reliability of the engine to withstand the entire 2500 km etc. 136 was not a worked out formula - if we had ended up with 138 or 134, we would have still settled for those numbers ! Oh so you had reference engine performance data from RDH, that is what I was asking.

The forged rods are slightly heavier than the stock rods - I would say about 40 grams heavier (each). Oh Ok.

The differentials were reinforced to prevent flexing, bending or breakage. This is a kind of "must do" for any Rally gypsy. Basically this involves welding of steel members to the front and rear differentials. Again, no pics right now ! Ok, Fine

Regds

My reply in bold above. Do share more about your ride with pics, that will make things more clear.

Spike

[Sutripta]

Originally Posted by sapl

Strenghtened internals (forged rods etc)
Strengthened bottom with custom designed block stiffener

Originally Posted by sapl

The strengthening was done to the rotating assembly. The most important of these being forged connecting rods. I have not taken any pics of the engine internals, will do so if we dismantle the engine sometime.

The forged rods are slightly heavier than the stock rods - I would say about 40 grams heavier (each).

Hi,
Great effort. Some queries.

What was the redline?

Pictures of the block stiffener. Method of attachment. Any data? If so, how measured.

Con rod heavier at which end? Material? What about the crank bobweights? Standard con rod bolts?

Cooling system?

Regards
Sutripta

[sapl]

Originally Posted by Sutripta

Hi,
Great effort. Some queries.

What was the redline?

Pictures of the block stiffener. Method of attachment. Any data? If so, how measured.

Con rod heavier at which end? Material? What about the crank bobweights? Standard con rod bolts?

Cooling system?

Regards
Sutripta

Please remember we are running a stock ecu with the Unichip piggyback ecu.

The redline was maintained at stock level (~6400 rpm). We did not increase the rev limit although we could have.

The block stiffener was designed by us after a lot of effort .. do you really want me to make our design public ? Well let me just say it is a simple device to ensure that the block is not unevenly stressed by the compression/combustion pressures.

We did not do an analysis about which end is heavier.. but I think that the main addition in weight comes from the body of the rod linking the small and the big end. The material is 4340 forged steel.

The crank remained stock. The conrod bolts are ARP.

Cheers

[sapl]

The engine management was done using the stock ecu working with a Unichip Q+ piggyback computer and a couple of ancillary modules.

The block diagram is given below.

While most of the functions were handled by the stock ecu, the following functions were influenced/controlled by the Unichip system:

1. Ignition timing
2. Injector control
3. Turbo boost control
4. Shift Light

We were therefore able to benefit from all the control and compensations provided by the orignal ecu while making the necessary changes to those of interest to us. e.g. Boost Control, Fuelling control, Shift Light activation etc.

We never had a starting problem at any time, thanks to ability of the original ecu to provide for easy starting under all conditions. Similarly all the compensations provided by the original ecu continued to be in place.

The Unichip and the Injector module were installed inside the glove box while the Turbo Module was installed in the engine compartment (see pics)

[maverick56]

sir
read with great interest the mods you did to the gypsy....grt
List of questions coming up......
Do you customize diesels also ?
I drive a bolero storm which has a scorp engine plonked in, need to increase power
can it be converted to 4x4?
Thar has the same engine and IFS, technically it should be possible
please let me know
regards
amar

[dhawcash]

Originally Posted by sapl

The dyno graphs for the Gypsy are enclosed.

During the tuning process, we wanted to see how far the engine will go and we managed up to 189+ bhp (could have gone more with bigger injectors).

We finally settled for around 136 bhp in the interest of durability and the ability of the other parts of car to handle the power.

Gave those dyno figures a deep stare. In addition to factors like reliability, the engine has much better torque spread in 136 bhp guise. A tractable engine would be better than a peaky one, if i'm right? or would you have chosen the 190 bhp mode during the rally if reliability was not an issue? (Have never driven a rally, but i think a relative lack of low- mid range torque would mean more gearshifts - and they takeaway precious time!)

[sapl]

Originally Posted by dhawcash

Gave those dyno figures a deep stare. In addition to factors like reliability, the engine has much better torque spread in 136 bhp guise. A tractable engine would be better than a peaky one, if i'm right? or would you have chosen the 190 bhp mode during the rally if reliability was not an issue? (Have never driven a rally, but i think a relative lack of low- mid range torque would mean more gearshifts - and they takeaway precious time!)

Well I would ignore the lower torque figures in the fist graph because that was before fine tuning. We would have got the same figures finally even if we had chosen to go the higher power map - so that would not have been a factor.

But we were clear from the beginning that we should not go in for wild amounts of extra power because we did not want to have unmanageable power, looking from the vehicle's chassis and the driver's point of view.

Even with the setup used, brake pad consumption was phenomenal - we would finish off a set of brake pads before the fuel in the tank got over !!

Regds.

[barua]

Interesting experiment , if I may so say.

Clearly, the engine mods overdid the design of the Gypsy and only the engine survived. Superb job, though.

Wonder what would be the acceleration and top speed if it were on an esteem with the 190bhps configuration ? 0-100k in 4sec? top of 250kmph?

[sapl]

Originally Posted by barua

Interesting experiment , if I may so say.

Clearly, the engine mods overdid the design of the Gypsy and only the engine survived. Superb job, though.

Wonder what would be the acceleration and top speed if it were on an esteem with the 190bhps configuration ? 0-100k in 4sec? top of 250kmph?

That's an interesting way to state it !

Well as far as the top speed goes, the normal ratios would only allow a top speed of about 190 km/hr at 6400 rpm. However, if the final drive ratio were brought down to 3.8, we could do a top speed of about 220 km/hr.

Cheers !

[barua]

Originally Posted by sapl

That's an interesting way to state it !

Well as far as the top speed goes, the normal ratios would only allow a top speed of about 190 km/hr at 6400 rpm. However, if the final drive ratio were brought down to 3.8, we could do a top speed of about 220 km/hr.

Cheers !

190kmph is amazing on the mountain goat!

W o W , Super!

Incidently, I learnt to drive cars on a gypsy by sneaking out my uncle's gypsy on sunday afternoon's and I believe it's the closest a car can be to a bike

[sapl]

Originally Posted by barua

190kmph is amazing on the mountain goat!

W o W , Super!

Incidently, I learnt to drive cars on a gypsy by sneaking out my uncle's gypsy on sunday afternoon's and I believe it's the closest a car can be to a bike

The actual speed achieved by the driver during the Raid was 153 km/hr according to the gps. He was using 4 wheel drive high gear.

Regds.

[Baba_TeamSS]

Great project! Coming from the UK I took turbocharging for granted since everything is so freely available. But since coming to India I realise what a challenge it is. Been thinking for doing it to my Gypsy for a while now but afraid to open a new can of worms in the process.

Hats off to you my friend

[stuntfreak]

Great Stuff! Kudos to you!

Would like to meet up and see the vehicle some time.

[sapl]

Originally Posted by Baba_TeamSS

Great project! Coming from the UK I took turbocharging for granted since everything is so freely available. But since coming to India I realise what a challenge it is. Been thinking for doing it to my Gypsy for a while now but afraid to open a new can of worms in the process.

Hats off to you my friend

Originally Posted by stuntfreak

Great Stuff! Kudos to you!

Would like to meet up and see the vehicle some time.

Thanks to both of you for the remarks !

You are welcome to visit any time.

We had prepared 4 more Gypsies with superchargers for the 2012 Raid de Himalaya. One of them was placed 3rd and the other 5th.

I will post the details some time.

[sapl]

We are just finishing another Gypsy Turbocharging project. One of the goals we had set was to ensure minimal clutter in the engine compartment so that:

a) Accessibility to key engine components is not hampered.
b) A water-cooled intercooler system is used to give better performance
c) Reliability of the vehicle is enhanced by ensuring minimal interference of components with one another.
d) The installation should have the same standards as an OE installation.

The build is nearing completion, and I will be posting more pictures with details in the next few days.