Standard 450, how many BHP will she make with minor mods??

[Macbags]

I’ve a totally standard 450 that I bought last summer and I’ve just started a few minor mods including ACT induction hoses (just fitted this last weekend), CliveF y piece on order and once all fitted its off to a well respected tuner for remapping.

She currently produces 286 bhp......will I be able to break through the magic 300 mark?

What are your guesses?

[Classic Chim]

You can expect 10 or more from Clive’s Y so you should be very close to it.

Do you have a Dyno graph of the 286hp as that’s not shabby.

Goodluck and do come back and post results,,, graphs tell you a lot.

My 450 was mapped at powers after rebuild and new ecu using catted Y 300 Hp 13.1 sec 1/4 mile
Put Clive’s Y on ( no re map) 12.7 sec 1/4 mile but did have RAINSPORT tyres on

I think mines about 310 fully de catt using Clive’s Y but that’s a guess but based on drag times it seems about right when running alongside 5.0 Chims with 325hp from a known mappers dyno.

Edited by Classic Chim on Monday 20th January 18:46

[ChimpOnGas]

Classic Chim said:

You can expect 10 or more from Clive’s Y so you should be very close to it.

Do you have a Dyno graph of the 286hp as that’s not shabby.

Goodluck and do come back and post results,,, graphs tell you a lot.

My 450 was mapped at powers after rebuild and new ecu using catted Y 300 Hp 13.1 sec 1/4 mile
Put Clive’s Y on ( no re map) 12.7 sec 1/4 mile but did have RAINSPORT tyres on

I think mines about 310 fully de catt using Clive’s Y but that’s a guess but based on drag times it seems about right when running alongside 5.0 Chims with 325hp from a known mappers dyno.

Thats a fast car you've git there Alun, my mate has a healthy but stock 500 that makes 300hp on the nose proving there really is no difference between a good 450 like yours and stock 500, of course 450's don't have the reputation for breaking their crankshafts so I know which one I'd prefer.

I've extracted 250hp & 260ft/lbs from my 400 with no head work, but the cost of taking it any further felt disproportionate so I decided to put my money into brakes and suspension instead, even after that £2,500 for a measly 30hp gain seemed poor value for money when for the same sum I could future proof my chassis. As you've said elswhere Alun, on the road theres not much to seperate all the engine sizes, I'd imagine on the track it would be a very different story though so I guess it boils down to what the OP intends to use his TVR for

For me an after market engine management system, a set of Uniroyal Rainsport 3s, the Brembo big brake conversion and a set of Mk4 Tuscan 'S' Bilsteins were worth way more than chasing horse power numbers on a dyno, my car is noticably smoother and faster from A-B with these additions and easily the equal for my mate's 300hp Chimaera 500 on enjoyable A & B roads.

My advice to the OP would stop shooting for more power before he completely satisfies himself he's addressed all the well known handling, braking, and drivability improvements first... he should then take a close look at the condition of his chssis before he goes spending his money on engine performance mods.

[Macbags]

Hi guys..... not particularly chasing HP but would like to max out what I can sensibly have while also ensuring I can take her back entirely to stock if I want to if selling in the future.

Induction upgrades minimal cost and have retained the original flexi pipe ( albeit I really can’t imagine ever changing it back)

CliveF y piece is as much for the sound as the extra horses, original will be restrained for mot and future sale

Remap..... well I see that as sensible all ways round and she is 20 years old.....would also be nice to get a few extra mpg

What do I want..... the best all round car I can. I may track her occasionally, I’ve no plans to ever go down the strip, but living near MK I do have a nice race track to explore (observing the speed limit of course)

Oh.... the OP has a name you know!

[Macbags]

[Macbags]

[ChimpOnGas]

Macbags said:

Seems like a fit 450 Charlie

[Macbags]

Sorry don’t follow what you mean?

[SteveR1979]

Watching with interest. I'd say thats a strong starting point.

I have a 450, with the ACT inlet pipework, carbon trumpets and performance manifolds.

I also have a stealth cam from V8D waiting to go in, then off to Joolz for a remap.

Be interesting to see what you end up with!

Edited by SteveR1979 on Monday 20th January 21:31

[Classic Chim]

Macbags said:

Sorry don’t follow what you mean?

It’s got Charlie written on the sheet.
I’d give away a tad of power to keep that all important usability.
As you say Mac it’s the overall package that matters.
I pointed out 1/4 mile times not as a brag in anyway but to point out the clear and very real difference 1/2 a second makes, its about 10 yards or more gain over 440 yards which in racing turns is massive. All from changing my Y piece. And it took me up the leader board a bunch of important places, none of these cars are slow.

It’s about proving the mods in real time. Graphs tell us so much, racing other Tvr in a controlled environment is very interesting, you see where one engines stronger than another or where one has more torque Or indeed Hp which in Hp case is always evident when at high revs, the bigger Hp takes over and you pull away in each gear.

Ask me why I know, damn yellow 5.0 kept beating me ( an in joke amongst friends ) Jackson 4 his car is awash with mods
Great fun I tell you.
Sorry I digress, the point is you can gain a good idea of your cars 1/4 potential based on its power numbers quite well.
Any standard Chim getting under 14 seconds is a tall ask if you ask me. Not many on the Tvr leaderboard are what you’d call standard.

Edited by Classic Chim on Monday 20th January 21:38

[Macbags]

CC completely misread your earlier post......looking back not sure how?

Dyno run was at the TVR gathering at Surrey Rolling Road just before Christmas. It was a good day out but now proving a bit more expensive as now doing a few minor mods in the hope of joining the 300 club.

I’m interested to hear your thoughts on rainsports. Mine is current shod with Bridgestone S02’s. plenty of tread on them so not likely to change anytime soon. Tyres were good in the summer but feel a bit hard and a bit more nervous in the cold.....

Macbags aka Charlie

[Classic Chim]

Macbags said:

CC completely misread your earlier post......looking back not sure how?

Dyno run was at the TVR gathering at Surrey Rolling Road just before Christmas. It was a good day out but now proving a bit more expensive as now doing a few minor mods in the hope of joining the 300 club.

I’m interested to hear your thoughts on rainsports. Mine is current shod with Bridgestone S02’s. plenty of tread on them so not likely to change anytime soon. Tyres were good in the summer but feel a bit hard and a bit more nervous in the cold.....

Macbags aka Charlie

I’m totally confused as usual! No probs
RAINSPORT 3 are marvelous.
I think they produce a newer version again
Cheap but very effective all year tyre.
My car was very nervous, now it’s got way more grip on these tyres and so much better over bumps.
Very pleased I chose them.

Simple test used in racing with a gauge but your hands a good judge.
Take a drive out and get upto speed, good 20 minutes driving, tyres should be hot, not Luke warm or in my case stone cold.
Even on a cold day the RS warm up. It’s great.

Edited by Classic Chim on Monday 20th January 23:18

[Macbags]

SteveR1979 said:

Watching with interest. I'd say thats a strong starting point.

I have a 450, with the ACT inlet pipework, carbon trumpets and performance manifolds.

I also have a stealth cam from V8D waiting to go in, then off to Joolz for a remap.

Be interesting to see what you end up with!

Edited by SteveR1979 on Monday 20th January 21:31

Steve, I’m hoping I lucked out as I bought her in the summer based entirely on condition and the sense that she had a strong engine. ( the colour wasn’t a first choice but it’s really growing on me!!)

Had a trip out with the PistonHeads gang to SRR encouraged to bring along a stock car for a ‘benchmark’ She was predicted at c 250 so to get 280+ was a huge bonus. Who knows what spec TVR decided to build her to?

Edited by Macbags on Tuesday 21st January 15:48

[SteveR1979]

Macbags said:

SteveR1979 said:

Watching with interest. I'd say thats a strong starting point.

I have a 450, with the ACT inlet pipework, carbon trumpets and performance manifolds.

I also have a stealth cam from V8D waiting to go in, then off to Joolz for a remap.

Be interesting to see what you end up with!

Edited by SteveR1979 on Monday 20th January 21:31

Steve, I’m hoping I lucked As I bought her in the summer based entirely on condition and the sense that she had a strong engine. ( the colour wasn’t a first choice but it’s really growing on me!!)

Had a trip out with primarily the PistonHeads gang to SRR encouraged to bring along a stock car for a ‘benchmark’ She was predicted at c 250 so to get 280+ was a huge bonus. Who knows what spec TVR decided to build her to?

This is the issue with TVR. You never quite know what the engines got! I've had people tell me that all the 450s have big valve heads, and yet other people tell me the complete opposite. These are all TVR experts!!

I don't know what mine has, but I'd like to see 300bhp out of it when I'm done. The manifolds made a huge difference. I do have one of Clives Y pieces here but I never got around to fitting it, so I can't comment on how effective it is, but the reviews are all positive.

I have also picked up a set of injectors for mine. They are "red" and from a Vauxhall. Apparently they are a straight swap and give a much better spray pattern. Probably no power increase but might increase efficiency.

[Classic Chim]

Macbags said:

Steve, I’m hoping I lucked As I bought her in the summer based entirely on condition and the sense that she had a strong engine. ( the colour wasn’t a first choice but it’s really growing on me!!)

Had a trip out with primarily the PistonHeads gang to SRR encouraged to bring along a stock car for a ‘benchmark’ She was predicted at c 250 so to get 280+ was a huge bonus. Who knows what spec TVR decided to build her to?

I see your car is a 2000 year model Charlie. Same as mine,, good choice

Your engine will likely be totally standard Rover with a Tvr cam fitted.
No head or porting work or any other internal changes .
I was told Rover took onboard What the likes of John Eales were doing with these engines in the early to mid 90’s onwards and took a lot of the ideas and development work he and Tvr Power did and to some extent added that to the very last engines before they went Thor induction.
The late Rover heads are the best they did for instance with the biggest valves you can get as standard.
Castings were improved on the blocks as was the webbing strengthening.
Your engine is as good as it’s gets in standard form.

[pac1uk]

For a road car I find torque more important than bhp. Good low down torque with a good mid range power delivery.

I find the Stealth cam excellent, produces good mid range power without compromising low down power.

My 4.6 with a Stealth cam is producing:-

At 1500 rpm torque is 280 lb ft, peaking to 340 lb ft around 3800 rpm

Max bhp is 314 @ 5500 rpm

[phazed]

My own 4.6 when I first bought it had 275 BHP or thereabouts.

That had standard range Rover heads, a typhoon camshaft, 72 mm throttlebody but otherwise standard.

Charlie, judging by your graph your car has a little something already.

Unfortunately there are no easy answers to bring you up to 300 easily. You could improve induction, change the injectors and check that you have the 72 mm throttlebody. Otherwise the best idea but certainly not cheap is a pair of V8 development stage four big valve heads, (others are available) which with the 72 mm throttlebody and a decent camshaft should give you 310–320 bhp. If your engine is in good condition which by the sounds of it, it is.

[Classic Chim]

pac1uk said:

For a road car I find torque more important than bhp. Good low down torque with a good mid range power delivery.

I find the Stealth cam excellent, produces good mid range power without compromising low down power.

My 4.6 with a Stealth cam is producing:-

At 1500 rpm torque is 280 lb ft, peaking to 340 lb ft around 3800 rpm

Max bhp is 314 @ 5500 rpm

Mine 1500 revs 276 ft lb Peaking at 339 at 3800 rpm. Catted Y.
That’s adding 15% road train loss. Many use 17% as a calculation which takes mine to almost 350 ft but that’s being ambitious I believe.

We would have a lot of fun up a runway, neck and neck comes to mind if I ran de catt.
I totally agree with your comments re torque over BHP on a road car, where the hell are you going to drive fast enough on a road to use the BHP effectively. I love to grunt far more.

Nice engine by the way


Peter I believe Charlie’s power curve is Catted. It’s probably already 300 Bhp de Catted, possibly a bit more.
Fingers crossed. It’s ages since a good engine debate took hold.

Edited by Classic Chim on Tuesday 21st January 09:52

[Macbags]

Classic Chim said:

I see your car is a 2000 year model Charlie. Same as mine,, good choice

Your engine will likely be totally standard Rover with a Tvr cam fitted.
No head or porting work or any other internal changes .
I was told Rover took onboard What the likes of John Eales were doing with these engines in the early to mid 90’s onwards and took a lot of the ideas and development work he and Tvr Power did and to some extent added that to the very last engines before they went Thor induction.
The late Rover heads are the best they did for instance with the biggest valves you can get as standard.
Castings were improved on the blocks as was the webbing strengthening.
Your engine is as good as it’s gets in standard form.

Are there any external visible signs that may suggest any previous work or upgrades.

Attached photo is of the engine bay when fitting the ACT induction hoses. Only other changes have been a new coil, amplifier and HT leads (all standard and from TVR Parts)

Edited by Macbags on Tuesday 21st January 16:10

[SteveR1979]

Macbags said:

Are there any external visible signs that may suggest any previous work or upgrades.

Attached photo is of the engine bay when fitting the ACT induction hoses. Only other changes have been a new coil, amplifier and HT leads (all standard and from TVR Parts)

Edited by Macbags on Tuesday 21st January 16:10

Nothing jumps out.