300BHP and over

[jammygit]

How can i get over the 300 BHP mark on a 4.0HC? Over to the experts!!

[dannylt]

By paying a HUGE amount of money. A more cost efficient option is probably trading for a 5 litre car, then upgrading that. Or dropping in a pretty modified 4.6 engine, but then brake & suspension mods required.

danny

[Dave_H]

Dannys right, you'd be better off trading up to a 500. Or why not spend a bit on suspension and brake mods on your current car?, you'll get more performance out of it that way.

[Paceracing]

I doubt that even the TVR 5 litre V8 produces over 300 BHP as standard, despite what TVR say. A 4 litre engine would be quite highly stressed at this sort of output which would undoubtedly compromise reliability.

Jas.

[david beer]

I think doubt should read "know". Oh well, they are still quick, just like a 340bhp car !

[shpub]

quote:
I doubt that even the TVR 5 litre V8 produces over 300 BHP as standard, despite what TVR say. A 4 litre engine would be quite highly stressed at this sort of output which would undoubtedly compromise reliability.

All you need to do is change the cam,. air flow meter, fit a bigger plenum, decat it , get it re chipped and voila 300 bhp and the ability to run on plain unleaded. Cost the previous owner around 4000 pounds though.

A good 500 should be up in the 260-275 bhp territory which is significantly higher than the 200 from a 4 litre.

Steve
www.tvrbooks.co.uk

>> Edited by shpub on Monday 17th June 07:20

[gb61390]

Am I missing something?
Aren't TVR's figures:-

235bhp for 4.0
275bhp for 4.5
340bhp for 5.0

I've heard that TVR exaggerate bhp but it's not that far out is it?
Cheers..... Andrew

[JonRB]

quote:I've heard that TVR exaggerate bhp but it's not that far out is it?

Its not so much an exaggeration as a question of how you measure it. If you run an engine with no flywheel, no alternator, no pumps, in fact nothing that might put a load on it and possibly duct in some cold air with a nice big fan and then measure it, you might possibly get the claimed figure.

Drop the engine into a car and connect all the ancillaries including the transmission, and the power output drops to the figures Steve has mentioned.

As Obi Wan said - many of the things we believe are only true from a certain point of view.

>> Edited by JonRB on Monday 17th June 13:35

[gb61390]

Thanks for the explanation Jon.
Is it also true that the claimed bhp figures for the Speed 6 engines in the Tuscan/Tamora are pretty accurate? If so does that mean that TVR have altered their testing process?
Cheers..... Andrew

[dannylt]

The transmission etc. isn't included in any power figure, and stuff like the flywheel makes no difference. Basically, they were just massively optimistic. The figures are probably more realistic for the S6, but as far as I know only two have ever been tested - a Red Rose S6 at 360, and another at 373. The AJP8's appear to be 330 to 360, which is still a lot more than the Rover 500 at 265.

[markh]

quote:All you need to do is change the cam,. air flow meter, fit a bigger plenum, decat it , get it re chipped and voila 300 bhp and the ability to run on plain unleaded. Cost the previous owner around 4000 pounds though.

A good 500 should be up in the 260-275 bhp territory which is significantly higher than the 200 from a 4 litre.

Steve could you let me more details eg which cam , airflow etc

many thanks Mark

[RCA]

If you want over 300 bhp on your 4.0, fit nitrous!!!, not permanent but v.good fun!!
Mine is being looked at to see what the maximum power it can take safely. Will let you know!!

[shpub]

quote:
Steve could you let me more details eg which cam , airflow

218 hybrid cam plus new rings. Enlarged plenum throttle body. Jaguar V12 air flow meter. Decat. Mark Adams rechip and rolling road session. Went from 268 bhp to 300. Cost around the 4-4500 mark including the engine work. I didn't pay for it though as the previous owner beat me to do it. Couldn't sell it though as many perceived it was too modified to trust. Their loss my gain.

PS it is on a 98 Griff 500
PPS also BHP is on plain U/L
PPPS Stopped me dropping the 520 engine into the car and building a bigger one for the 520!
Steve

>> Edited by shpub on Wednesday 19th June 16:25