new to Chimaeras - some questions
Discussion
Hi everyone.
Im a long-time member of the wedges forum, but have been TVR-less for a number of years having had a 390SE in the past.
There is a Chim on the cards. Originally a 400 with a 4.6 in it. Its a fairly standard cross bolt 4.6 built by RPI so no concerns there. the 14CU EFI has a Tornado chip in it, but other than that I suspect the injectors are probably the standard 185cc/min jobs as only a long engine was purchased. It is of an age where catalytic converters will effectively be mandatory.
So Ive got a couple of questions:
1) in the experience of Chimaera owners, how much de-catting can be done without falling foul of the MoT mans emissions tester? It has been alleged, and Im SURE it isnt true (...) that sometimes a handy Nissan Micra accidentally takes the probe..... Well I never! I am not averse to switching the headers and Y-piece out for track use if we really need the precats and main cat in for MoT testing. The car will almost certainly be converted over to run Megasquirt3Xtra, so mapping and the like wont be a problem. That isn't my first rodeo either.
2) There is talk of either a Rotrex blower or possibly even twin turbos. Rotrex seems a well trodden path if expensive, but turbos is a bit more of an unknown. Has anyone any experience with twin turbos a la Powers Performance?
3) I note there had been a few instances of snapped impeller shafts on the Rotrex C38 and I have personally seen a C30 do it - loss of boost and a funny tinkly noise! Ive spoken to the importers, and they did say that there have been design changes in the Rotrex head unit to improve reliability - i guess beefing up the shaft to stop it whirling or perhaps smoothing shoulders in the shaft to reduce stress. Does anyone have any recent reliability stories of the Rotrex units? The chap i spoke to did say that some of our more youthful brethren with high revving Hondas etc like to bounce the car off the rev limiter which is quite violent on the charger. I would be setting a soft rev limit to alleviate this, and possibly choosing a slightly larger trim of Rotrex and under driving it a tad - obviously we want to be staying nicely in the middle of the map to avoid just heating the charge air....
Anyway, Im possibly overthinking all of this.
I'd be interested to hear your thoughts on this stuff.
Ed.
Im a long-time member of the wedges forum, but have been TVR-less for a number of years having had a 390SE in the past.
There is a Chim on the cards. Originally a 400 with a 4.6 in it. Its a fairly standard cross bolt 4.6 built by RPI so no concerns there. the 14CU EFI has a Tornado chip in it, but other than that I suspect the injectors are probably the standard 185cc/min jobs as only a long engine was purchased. It is of an age where catalytic converters will effectively be mandatory.
So Ive got a couple of questions:
1) in the experience of Chimaera owners, how much de-catting can be done without falling foul of the MoT mans emissions tester? It has been alleged, and Im SURE it isnt true (...) that sometimes a handy Nissan Micra accidentally takes the probe..... Well I never! I am not averse to switching the headers and Y-piece out for track use if we really need the precats and main cat in for MoT testing. The car will almost certainly be converted over to run Megasquirt3Xtra, so mapping and the like wont be a problem. That isn't my first rodeo either.
2) There is talk of either a Rotrex blower or possibly even twin turbos. Rotrex seems a well trodden path if expensive, but turbos is a bit more of an unknown. Has anyone any experience with twin turbos a la Powers Performance?
3) I note there had been a few instances of snapped impeller shafts on the Rotrex C38 and I have personally seen a C30 do it - loss of boost and a funny tinkly noise! Ive spoken to the importers, and they did say that there have been design changes in the Rotrex head unit to improve reliability - i guess beefing up the shaft to stop it whirling or perhaps smoothing shoulders in the shaft to reduce stress. Does anyone have any recent reliability stories of the Rotrex units? The chap i spoke to did say that some of our more youthful brethren with high revving Hondas etc like to bounce the car off the rev limiter which is quite violent on the charger. I would be setting a soft rev limit to alleviate this, and possibly choosing a slightly larger trim of Rotrex and under driving it a tad - obviously we want to be staying nicely in the middle of the map to avoid just heating the charge air....
Anyway, Im possibly overthinking all of this.
I'd be interested to hear your thoughts on this stuff.
Ed.
I know nothing of superchargers, but do have one turbo on my car.
I know of two twin turbo cars, one RV8 engined and one Chevvy, but i am not sure why you would bother, as
a) it is not an easy install and
b) it develops so much power that you would effectively need to change the engine in order not to break it - all the internals would have to be strengthened.
c) it is almost bound to give you serious under-bonnet heat issues
Mine is a bog standard Range Rover 4.6 engine, so low compression, with Range Rover heads and cam, so low or no valve overlap. Eann Whalley GT35 turbo kit inc intercooler and oil cooler, Emerald ECU, and it makes 395 bhp and 525 torques with half a bar of boost.
Adequate for everything I want to do with it, i.e. road and track day use, as I am not interested in the two most popular TVR sports, car shows and willy waving.
Go much over 400 bhp on an RV8 and you will be into a whole world of wallet pain and rebuilds. Or so i am reliably told.
I know of two twin turbo cars, one RV8 engined and one Chevvy, but i am not sure why you would bother, as
a) it is not an easy install and
b) it develops so much power that you would effectively need to change the engine in order not to break it - all the internals would have to be strengthened.
c) it is almost bound to give you serious under-bonnet heat issues
Mine is a bog standard Range Rover 4.6 engine, so low compression, with Range Rover heads and cam, so low or no valve overlap. Eann Whalley GT35 turbo kit inc intercooler and oil cooler, Emerald ECU, and it makes 395 bhp and 525 torques with half a bar of boost.
Adequate for everything I want to do with it, i.e. road and track day use, as I am not interested in the two most popular TVR sports, car shows and willy waving.
Go much over 400 bhp on an RV8 and you will be into a whole world of wallet pain and rebuilds. Or so i am reliably told.
QBee said:
Mine is a bog standard Range Rover 4.6 engine, so low compression, with Range Rover heads and cam, so low or no valve overlap.
Eann Whalley GT35 turbo kit inc intercooler and oil cooler, Emerald ECU, and it makes 395 bhp and 525 torques with half a bar of boost. Adequate for everything I want to do with it, i.e. road and track day use, as I am not interested in the two most popular TVR sports, car shows and willy waving.
Go much over 400 bhp on an RV8 and you will be into a whole world of wallet pain and rebuilds. Or so i am reliably told.
I have to respect your approach Anthony, and I especially love the way you're able to make turbo charging your TVR sound so sensible Eann Whalley GT35 turbo kit inc intercooler and oil cooler, Emerald ECU, and it makes 395 bhp and 525 torques with half a bar of boost. Adequate for everything I want to do with it, i.e. road and track day use, as I am not interested in the two most popular TVR sports, car shows and willy waving.
Go much over 400 bhp on an RV8 and you will be into a whole world of wallet pain and rebuilds. Or so i am reliably told.
Respect for achieving your objectives this way mate, it wouldn't have been cheap I'm sure but certainly way way cheaper than most who've shot for 400 horsepower from a Rover V8
Now, stop being sensible and make an in-car video of your turbo Chimaera so we can all see how it goes
Back to the OP Ed.:
1. Pre-cats not required for MOT as they only serve a purpose when engine/exhaust gases are cold. Main cat in Y-piece technically required but there are sympathetic testers out there.
2. My set up : TVR issue 450 (4.6) with Rotrex C38-91 & intercooler + Bosch Green Giant 440cc injectors, 13psi boost, otherwise standard - run for 18 months & 5,000 miles @ 425hp.
Stripped down engine. Now - Custom forged pistons, reground crank, JE billet rocker shafts & support posts, MBE 9a9b ECU, otherwise as before - been running for 3 years & 8,000 miles @ around 500hp.
No issues with Rotrex, change s/c filter every 6,000 miles & fluid @ 12,000 (although I've changed mine sooner).
Self install at home in reasonably well equipped garage. Engine strip down & machining at Powers Performance.
However, before adding power beef up brakes, suspension, clutch & (depending how far you you want to go) drivetrain - particularly driveshafts, cv joints, etc. (BTR diff will cope, T5 box with 5th gear upgrade will manage - unless you're an animal!).
1. Pre-cats not required for MOT as they only serve a purpose when engine/exhaust gases are cold. Main cat in Y-piece technically required but there are sympathetic testers out there.
2. My set up : TVR issue 450 (4.6) with Rotrex C38-91 & intercooler + Bosch Green Giant 440cc injectors, 13psi boost, otherwise standard - run for 18 months & 5,000 miles @ 425hp.
Stripped down engine. Now - Custom forged pistons, reground crank, JE billet rocker shafts & support posts, MBE 9a9b ECU, otherwise as before - been running for 3 years & 8,000 miles @ around 500hp.
No issues with Rotrex, change s/c filter every 6,000 miles & fluid @ 12,000 (although I've changed mine sooner).
Self install at home in reasonably well equipped garage. Engine strip down & machining at Powers Performance.
However, before adding power beef up brakes, suspension, clutch & (depending how far you you want to go) drivetrain - particularly driveshafts, cv joints, etc. (BTR diff will cope, T5 box with 5th gear upgrade will manage - unless you're an animal!).
Edited by Richard 858 on Tuesday 29th January 20:26
Nice one Richard, excellent power right across the rev range.
so, fella, you have two choices: be happy with 400 bhp and keep much of the engine standard ( I too have bigger brakes and Jolly Green Giant injectors or similar - I think mine where Blue Knight, but who cares?), or spend some money on internal engine upgrades and you will be able to go to 500 bhp
so, fella, you have two choices: be happy with 400 bhp and keep much of the engine standard ( I too have bigger brakes and Jolly Green Giant injectors or similar - I think mine where Blue Knight, but who cares?), or spend some money on internal engine upgrades and you will be able to go to 500 bhp
Qbee's route probably more sensible and cost effective and Dom does some cool stuff. I got out of hand, went mental, spent a fortune and spent many, many hours building it, along with different gearbox/clutch/driveshafts/brakes/ suspension etc but I did get this below. Fookin' 'ell once you got traction usually past 80-90 YEE-Fookin- HA! sorry, couldn't help it and yes, I miss it. Well, wouldn't you?
Edited by macdeb on Wednesday 30th January 17:41
Edited by macdeb on Wednesday 30th January 17:45
Edited by macdeb on Wednesday 30th January 17:47
macdeb said:
Qbee's route probably more sensible and cost effective and Dom does some cool stuff. I got out of hand, went mental, spent a fortune and spent many, many hours building it, along with different gearbox/clutch/driveshafts/brakes/ suspension etc but I did get this below. Fookin' 'ell once you got traction usually past 80-90 YEE-Fookin- HA! sorry, couldn't help it and yes, I miss it. Well, wouldn't you?
I’m just trying to get my head around this, that’s insane Edited by macdeb on Wednesday 30th January 17:41
Edited by macdeb on Wednesday 30th January 17:45
Edited by macdeb on Wednesday 30th January 17:47
At 2000 revs you have ZERO 0 hp.
It doesn’t matter as you have 200 ft of torque at that point
Here’s where it warps the mind
leaves time behind ?At 3000 revs you have somethimg like 160 hp 280 ft torque, fairly normal at this point
Warp speed then takes over,
From 3000 revs to 5000 it goes from 160 to 572 hp
And 280 to 600 ft lb torque if I’ve read that correct.
So in those 2000 revs the power going through those rods and crank are incredible. Some build that man some build.
And that’s why it looked like your car was twice as fast as mine when we dragged them,, because it was
Edited by Classic Chim on Wednesday 30th January 21:07
Richard 858 said:
Awesome Mac, yes I would bloody miss it, and I'm sure you do. Yours was & still is the best I've ever seen (but I'm trying my best). If 18% drivetrain loss is applied then I maxed out 20hp short! but still running through T5 box. My cocks getting cold now!!I would have quite likely got carried away, but for the sage council of Mat Smith. He knows what I do with the car and how far my budget won't stretch. From his racing experience allied to his knowledge of my relative lack of driving skill, he advised me where to stop before I took the car to Jools for the Emerald and mapping. I had to tie Jools' hands behind his back to keep the car under 400 bhp - he, like me, wanted to know just how far it would go.
Apparently he hit 429 bhp without me present before the car blew off an intercooler pipe. The next morning I went to help him find the sudden loss of boost (it wasn't immediately obvious that it was a blown off pipe), and then passed on Mat's wisdom regarding keeping it the sensible side of 400 bhp. After the full wallet out, body off, new engine, turbo and Emerald, I really couldn't afford to break it, and Mat was convinced that with my lack of driving skills, more than 400 bhp was likely to be a handicap rather than a help on track days. As well as taking me into the areas of forged pistons, drive shafts, diff, gearbox etc etc etc. I have to say two things - 395 bhp suits me fine, there is no turbo lag at low boost, and whilst it is clearly faster than the 315 bhp I had before, it doesn't actually feel night and day faster. I couldn't even beat Peter Jackson's NA 5 litre on the drag strip, thanks to his skill at getting off the line being greater than my extra power.
Advice to those about to about to have open wallet surgery - go drive a few before you start making decisions, and stick to whatever fully costed plan you settle on.
Richard, we will have to rename you Private Frostbite
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