Has anyone gone beyond 4.0L in their engine upgrade.

[icraigmy]

Just for interest, I recently had my Tamora 3.6L Sp6 engine upgraded to 4.0L RR spec and wondered if anyone has actually gone beyond 4.0L in their upgrade, to maybe 4.5L.

[macca666]

Thats a question I would also like to know the answer to.

If your engine is knackered then it makes sense to spend £7K on a 4 litre rebuild, but if its not knackered than £7K is too much in my opinion for only gaining say 30 to 40 horses.

Mine is not knackered and so am happy to spend cash but I would be looking for around 100BHP more than my existing 350. ( I only got a baby 3.6 at present)

[TJW]

Paul at Austec is running a 4.2 crank in his, but It would cost in excess of 3k just for the custom crank. I think its pushing around 420bhp too.

[rpa.janwell]

Our T440R has a 4.2 S6 engine - with a 215+ mph rating.

[TSS]

rpa.janwell said:

Our T440R has a 4.2 S6 engine - with a 215+ mph rating.

Is it geared to enable 215+ and have you ever got anywhere near that top speed?

[tail slide]

macca666 said:

Thats a question I would also like to know the answer to.

If your engine is knackered then it makes sense to spend £7K on a 4 litre rebuild, but if its not knackered than £7K is too much in my opinion for only gaining say 30 to 40 horses.

Mine is not knackered and so am happy to spend cash but I would be looking for around 100BHP more than my existing 350. ( I only got a baby 3.6 at present)

A 4.5 is possible with high power/torque, but unavoidably more expensive than £7k if also want optimum reliability. Plus all the standard transmission won't cope. And how are your brakes?

On the other hand, it's the only solution for big power/torque if keeping it original - which I want to, and I must anyway to meet reg's for my occasional use for sprint/hillclimbs.

It can be supercharged/turbocharged of course, at higher still cost as much of the engine and systems have to be re-designed to cope with all the extra heat and stresses.

I'll post the results & any issues when mine's running if anyone's interested; I finally have all the high-spec parts as specced/designed by Autocraft and it's being professionally assembled by Dulford's next month.

[tail slide]

rpa.janwell said:

Our T440R has a 4.2 S6 engine - with a 215+ mph rating.

pls share the mouth-watering spec Richard?

Hopefully your beastie is nearing completion...

[Targarama]

TSS said:

rpa.janwell said:

Our T440R has a 4.2 S6 engine - with a 215+ mph rating.

Is it geared to enable 215+ and have you ever got anywhere near that top speed?

Am I the only one who would never want to drive a TVR that fast?

I just had the diff changed on mine, lowering theoretical top speed from 196mph to 176mph. Much more realistic and probably what 350hp could pull. Top speed is down to HP (and aero). You'd need 550hp or maybe more to pull 215mph - look at the mega supercars' figures.

[Tangoed]

This is quite true, why bother with an engine upgrade when changing your diff to something like a 3.7 or 3.9 has the same effect. OK you wont see the top end of 180 but would you ever. I've had the 3.9 diff just fitted in mine and what a difference, the revs are there on demand and not the case of wait a while to wind it up. An engine upgrade is 5K a diff is 1.5K. food for thought.

[macca666]

Got to say I probably like the idea of the new diff.

Your right - scares the shit out of me at 130 mph because you are defo gong to die if you hit anything.

From what I already thought, and it seems to be confirmed here, it costs megga bucks to get only a small amount of extra php.

Its the 0 - 100 acceleration I am interested in.

[tail slide]

Targarama said:

Am I the only one who would never want to drive a TVR that fast?

I just had the diff changed on mine, lowering theoretical top speed from 196mph to 176mph.

3.9 diff definitely the best v. for money mod for acceleration. Mine's sat on garage floor waiting for chance to install

[Daftlad]

tail slide said:

Targarama said:

Am I the only one who would never want to drive a TVR that fast?

I just had the diff changed on mine, lowering theoretical top speed from 196mph to 176mph.

3.9 diff definitely the best v. for money mod for acceleration. Mine's sat on garage floor waiting for chance to install

Saga Lout, CR box, 3.91 diff, R888s - bliss........

[Tangoed]

Like a few of the guys on here I had my diff done at Topcat Racing. I've already got the close ratio box fitted, but he they can also do this at the same time. Maxx waxx has just had both fitted to his car.

I was at Silverstone yesterday on a track day and bumped into the guys from Topcats. They said that in the past two weeks they've fitted about six 3.9 diffs.

Daftlad, R888,close ratio box and 3.9 diff Yesterday was sheer bliss

Edited by Tangoed on Wednesday 22 August 07:10

[hab1966]

How much are these diffs and how much is fitting.

Are they different to the Quaife ones that are also mentioned in this forum?

(Edit: whoops they might be the same as the Quaife ones as i note Tailslide has posted here and also posted the Quaife thread!)

Edited by hab1966 on Wednesday 22 August 08:28

[David Godfrey]

tail slide said:

Targarama said:

Am I the only one who would never want to drive a TVR that fast?

I just had the diff changed on mine, lowering theoretical top speed from 196mph to 176mph.

3.9 diff definitely the best v. for money mod for acceleration. Mine's sat on garage floor waiting for chance to install

Any idea how much of a difference this actually makes to acceleration? has anyone got before and after figures?

[Daftlad]

Tangoed said:

Like a few of the guys on here I had my diff done at Topcat Racing. I've already got the close ratio box fitted, but he they can also do this at the same time. Maxx waxx has just had both fitted to his car.

I was at Silverstone yesterday on a track day and bumped into the guys from Topcats. They said that in the past two weeks they've fitted about six 3.9 diffs.

Daftlad, R888,close ratio box and 3.9 diff Yesterday was sheer bliss

Edited by Tangoed on Wednesday 22 August 07:10

I bet you surprised a few folk!!

[Targarama]

hab1966 said:

How much are these diffs and how much is fitting.

Are they different to the Quaife ones that are also mentioned in this forum?

(Edit: whoops they might be the same as the Quaife ones as i note Tailslide has posted here and also posted the Quaife thread!)

Edited by hab1966 on Wednesday 22 August 08:28

No this is the not the Quaife parts. It is simply a change in crown wheel & Pinion on the standard Hydratrak diff. Cost at Topcats is around £1200 for 3.91 and a little less for 3.73 (less bits needed). (Most cars have 3.46/3.54 as standard - I forget the exact number now).

They need to remove the diff, open it up and rebuild it with new seals, oil etc. Then it is best to replace the top diff bush while the diff is out (it requires diff removal to replace). So a few hours labour for the diff out/in and the labour for the 'bench' work. Plus parts.

Before anyone asks, it is no noisier than the std diff (apart from the fact that you will be revving higher in every gear any any particular speed).

Please don't think this is like getting 100hp more. It is simply making the existing power available sooner on the road.

[Maxx-Waxx]

hab1966 said:

How much are these diffs and how much is fitting.

Are they different to the Quaife ones that are also mentioned in this forum?

(Edit: whoops they might be the same as the Quaife ones as i note Tailslide has posted here and also posted the Quaife thread!)

Edited by hab1966 on Wednesday 22 August 08:28

CW&P cost about 800 for 3.9 fitting about 650.

I had mine done last week along with CR gear set. Although not had time enough to fully appreciate the improvements as i went straight on hols after. Drive home i took it relatively steadily just to allow things to bed in properly, but even with using fewer revs the car felt much more responsive.

N

[icraigmy]

Oh heck, and I thought I'd have a few months off spending money on my Tiv. Here we go again so to speak, now for my next upgrade ... 3.9 Diffs ....

I only did the post for interest as I'm very happy with my 4.0L engine upgrade, Nitron Shocks, and the ACT Carbon Fiber Air Tight Air Box recently fitted. Thought that was it for a while

[Targarama]

icraigmy said:

Oh heck, and I thought I'd have a few months off spending money on my Tiv. Here we go again so to speak, now for my next upgrade ... 3.9 Diffs ....

I only did the post for interest as I'm very happy with my 4.0L engine upgrade, Nitron Shocks, and the ACT Carbon Fiber Air Tight Air Box recently fitted. Thought that was it for a while

<Dr Evil>
Mwa hah hah
</Dr Evil>