Is a Chimaera 4L Underpowered?
Discussion
I am a new boy so hi all! About a year ago I bought a 4L Chim in beautiful condition with only 16k on the clock and FTVRS etc. My gripe is that the car is lacking in mid-range torque. It has a sports exhaust and makes a great sound but that's it really--looks apart. My BMW M5 has much more torque and driveability. I added an induction kit and fast cam and must admit that with the Tornado chip it accelerates like a bat out of hell but driveability is just not there. Have to push the stick around a lot to get any sort of real performance. I am told that RR figures for this car are only about 160bhp at the wheels--a bit more in my case with the mods. Is this a general experience? Perhaps I should save up for a 5L but is that all that much better? A Cerbie is attractive but I would miss the soft-top. Seems that what I have is an old fashioned English sports car like
a TR6
a TR6
Thanks for the opinions guys. I think I have found the answer. A friend of mine is having his 4L upgraded to 5.1L by V8 Developments. Total cost with all the usual upgrading £5350 plus VAT. V8 assure him that this mod gives a GENUINE 320bhp at the wheels. So modify or upgrade. Upgrade I think as the 4L is such a responsive car.(:
GreenV8S said:
magnus said: Thanks for the opinions guys. I think I have found the answer. A friend of mine is having his 4L upgraded to 5.1L by V8 Developments. Total cost with all the usual upgrading £5350 plus VAT. V8 assure him that this mod gives a GENUINE 320bhp at the wheels. So modify or upgrade. Upgrade I think as the 4L is such a responsive car.(:
Is that just to supply and fit the engine, or does it cover the clutch, strengthened gearbox, an uprated diff and half shafts, plus major work on the suspension and brakes? I would expect the total cost to work out roughly double the cost of the engine work.
Very good question. I have now seen the upgrade specification sent by V8. It covers clutch and brakes but no mention of suspension, gearbox or diff. but there is a little sting in the tail; the last item reads " road test and advise on handling" perhaps this is when the "suspension upgrade required" costing heaven knows what hits the customer. I know very little about all this but would a diff. gearbox and suspension upgrade be needed for ordinary road use. Is he really going to have pinions shattering etc the old rover gearbox seems to me to be the strongest part of the car. Trackdays of course are a different matter.
shpub said: There is no substitute for cubic inches....
WGR I don't know. The design of the engine is surely important after all a GP car has limited capacity but churns out enormous power at the other end a classic 8L 12 pot RR moves like a milk churn. The V8 used in my Chim. seems to be a very old design and I imagine that a much smaller capacity engine as used say in a WRX would make rings around it.
manek said:
magnus said: Thanks for the opinions guys. I think I have found the answer. A friend of mine is having his 4L upgraded to 5.1L by V8 Developments. Total cost with all the usual upgrading £5350 plus VAT. V8 assure him that this mod gives a GENUINE 320bhp at the wheels. So modify or upgrade. Upgrade I think as the 4L is such a responsive car.(:
Imagine how much cheaper it would be to sell the 4 litre and buy a 5 litre car...
Just that a good 5L low mileage Griff or Chim would cost about an extra 10k AND would actually be less powerful than the modified 4L. No way does a standard 5L churn out 320bhp at the wheels--more like 260
jamieheasman said: Firstly, if this upgrade includes brakes and clutch mods, fitting and setting-up, I'd say it's a bargain!
Having said this, I'm interested by the comments to do with the mid-range characteristics of the 4.0litre. Sure it's never going to have the grunt of a 5.0litre but I think the main draw-back with all TVR Rover engined cars is the ignition system.
You have fitted a different intake system and camshaft and then had a chip-change. What you won't have changed is the timing as the curve is dictated by the distributor. Basically you can change the fuelling as much as you like but it's always going to be a compromise without being able to change the ignition curve as well. You've only got half a job done.
I bet with a mapped ignition you'd be happy with the 4.0litre.
An Emerald ECU for example(with fuel and ignition), is 500GBP. It's a very easy system to set-up and wouldn't cost much more than going the Mr Adams route. If I was considering an engine upgrade (any upgrade) this is the first thing I would do.
I think you'll be surprised by how much difference this makes.
Emerald ECU??? Assuming that you are not taking the p**** where can I get this magical ECU?
shpub said: If you want to see what it took to actually get 320 bhp+ at the wheels (400+ at the flywheel) go and look at the 520 story on www.t-v-r-services.co.uk and that will give you some idea of exactly what you are letting yourself in for.
Yes the gearbox will need sorting. Yes the transmission will need upgrading and yes your running costs will be high. You will need to look at cooling and suspension and expect rear tyres to last no more trhan 2000 miles. Also check that you can get the car insured as well as many insurers are refusing or increasing premiums to an extreme amount.
Thanks Steve!
I do get the message(I am afraid that I was misled on the 320 figure)so am looking for a 5L Chim or Griff. It does occur to me that even if 320bhp was achieved I do not see how you are going to put it down without traction control so what's the point.
2 sheds said: Fully mapped ignition is a good idea, not convinced that changing to fully mapped fuelling would be a benefit for a road car, there are no gains in torque, in some cases top end BHP has been increased but at a cost, I've used CUX hotwire injection on full race spec 5.0L with 350 bhp & torque.
I'm not saying that fully mapped systems like DTA don't work but IMO not worth the all the effort of fitting & mapping on a standard TVR.
Tim
absolutely agree! Just had an email from dave walker of emerald in which he suggests as the best option to fit a Vauxhall 60-2 toothed wheel to the crankshaft to act as the speed sensor and the air meter then becomes redundant. The throttle pot is used for load sensing.
Seems a pricy operation.
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