Speed Six In a Challenge Car

[shapeshifter]

I'm in the process of considering a new engine for my Challenge car, my everyday car is a road Tuscan 2 with the speed six engine, after 2 years and 32k miles all is well with it. From my point of view it seems very powerful generating 380bhp (so said the rolling road). Its said the race AJP will generate 450bhp however, most would seem to say it wont, I'm sure over the years the speed six has been discussed - could you enlighten me as to the reason why the speed six is not used?

[Graham]

Cliffs T350 Has a speed 6 in it and I believe Jes is now converting a tamora that will have a s6 engine.

I think the main reason there arnt many out there is that the cars are still fairly new and expensive.

[shapeshifter]

Graham said:

Cliffs T350 Has a speed 6 in it and I believe Jes is now converting a tamora that will have a s6 engine.

I think the main reason there arnt many out there is that the cars are still fairly new and expensive.

You can pick a speed six engine up for a similar price to that of an AJP, all else being equal, would the speed six perform like that of the AJP?

[itsallyellow]

shapeshifter said:

Graham said:

Cliffs T350 Has a speed 6 in it and I believe Jes is now converting a tamora that will have a s6 engine.

I think the main reason there arnt many out there is that the cars are still fairly new and expensive.

You can pick a speed six engine up for a similar price to that of an AJP, all else being equal, would the speed six perform like that of the AJP?

I cant see it would, less power less torque?? But i could be completley wrong.........

[trackcar]

The SP6 is nowhere near as good a race engine as the AJP8 so far .. it's lack of midrange is a real handicap .. however if you want to race a SP6 TVR then welcome .. we're doing it with Ceejay's T350 as Graham says above ..

we absolutely refuse to fit an alternative engine unless the point in time comes where the SP6 is proven to be a complete non-starter .. we just have to make up for it's shortcomings in other ways.

I'm very keen to race a T350 because of it's aero and I'm also very very very keen that it should keep it's SP6 engine .. if only because it fits and it's in keeping with our roots in the tasmin challenge of race your road car.

[GlynnsportRacing]

Hi Michael, I can only advise from my own experiences as my technical knowledge is somewhat limited. As an owner of a road Tuscan my experiences of the SP6 engine have been somewhat less successful than yours.

My first one (bought in 2000) lasted just 3000 miles, was rebuilt by the factory and managed another 1500 miles before expiring again. Needless to say got rid of that one. My current road Tuscan (2002) was much better and the engine lasted 17500 miles before going bang. Was rebuilt by the factory using their most updated engine parts and given a new one year warranty (this was in June 2005) and so far has been fine after a further 5000 miles. Fingers crossed, although I haven't dared to thrash it around the track this time, it seems in good order.

In my race Tuscan, I've always used the full AJP8 race engine. There's no doubt in my mind that it has much more torque, more power and was built for the purpose of race circuit sprinting. I agree that although they state they are 450bhp, they're probably more like 425bhp but nevertheless I'd be surprised if it wasn't quite a bit quicker that the SP6 and providing it's looked after well, quite likely to be at least as reliable and probably more so based on my experiences.

If it was me, I'd definitely go the AJP8 race engine route, which you know will fit without modification and keeps the race car in the form it should be. And quicker too! All the best,
Steve

[ceejay]

I have a speed6 engine in the T350 mainly to keep the car as it left the factory which makes it eligible for GT Cup racing too. If I was building a race Tuscan I'd probably go for the AJP8 because:-

it's compact
lightweight
chassis is ready for it to bolt straight in
easy to achieve 425+ bhp
good torque
proven race track record

I personally have faith in the speed 6, it's possible to get decent power and improve the torque. In a race tuscan I wouldn't re-invent the wheel in my first season.

ceejay

[shapeshifter]

Thatks lads, the situation I have is this:
My chassis is being powder coated next week, and I need to select the right engine, currently my car has a road cerb AJP engine however, it has got a steel crank, the chassis has been previously altered to allow for the sump of the road engine.
I'm going to stick with the AJP however, I'm now considering putting a proper dry sump race AJP engine in the car, if I do this, I can put the once removed bracing below the engine back into the chassis and then send it to the powder coaters - job done.
If I stick with the road AJP, and later find its under powered and then want to put a full race AJP in the car, I've got to sod around with the chassis again, is there going to be a considerable difference between the road and race AJP??

[teamHOLDENracing]

You protect the long term value of a Challenge car by having an original engine and this matters when the cars become eligible for historic racing (which has already started with the GT90s Revival).