4.0 L - Sensible rev limit?

[Rossco2010]

Quick question - what's a sensible rev limit for a properly warmed up, 4.0l in decent nick?

I think I'm probably changing up too early (3.5 -4k) when "pressing on" but don't want to thrash it (or spend the money on consequences of thrashing it!)

Cheers

[blueg33]

Rossco2010 said:

Quick question - what's a sensible rev limit for a properly warmed up, 4.0l in decent nick?

I think I'm probably changing up too early (3.5 -4k) when "pressing on" but don't want to thrash it (or spend the money on consequences of thrashing it!)

Cheers

I think I had mine set at about 5250 (hope I haven't remembered wrongly), and it revved up to that very quickly. They do run out of puff at the top of the rev range

edited - I definitely got that wrong! Mark (Blitzracing) may remember as he had a copy of my map.

In my experience the 4.0l and 3.9 rev more freely than the larger capacity engines, I was always hitting the limiter especially in 2nd and 3rd.

Edited by blueg33 on Thursday 14th April 21:34

[.Mark]

I think the rev limiter does vary for some reason, I've rarely hit the rev limiter, and have seen the needle pass 5500, but it's running out of steam about 5k or just after I think.

[v8 racing]

Rossco2010 said:

Quick question - what's a sensible rev limit for a properly warmed up, 4.0l in decent nick?

I think I'm probably changing up too early (3.5 -4k) when "pressing on" but don't want to thrash it (or spend the money on consequences of thrashing it!)

Cheers

3.5-4.0? really, if you ever decide to have an engine rebuild i will warrant it for life!!, seriously you are more than safe to 5.5.

[Rossco2010]

v8 racing said:

3.5-4.0? really, if you ever decide to have an engine rebuild i will warrant it for life!!, seriously you are more than safe to 5.5.

Yeah - 2 reasons:
1) Its my first v8, not had it that long, so didn't want to b*gger it
2) I drive like a blouse!

Thanks for that, will definitely push it a bit further.

Cheers

[.Mark]

Rossco2010 said:

Thanks for that, will definitely push it a bit further.

Cheers

And make sure you do We will all be listening.

It only really begins to roar at 3.5k.

[bigdods]

IIRC my 450 has the rev limit set at 6200 , but it runs out of puff at about 5500. But I often take it to 6k just to hear the noise.....

I would call changing at 4k short shifting as its right in the optimum power band, its where I change when I'm not in a hurry.

[Andy_mr2sc]

I often have mine in the 6k+ area just because it makes such a fantastic noise with a sleeved exhaust and no cats!!

[mgjc]

4.0l is 6250

[Tyre Tread]

mgjc said:

4.0l is 6250

Yep, that's where mine is.

I've hit the limiter a couple of times.

Generally I change up about 5K ish

[dog man]

Hmmm all you revv'ers out there mocking me with your abilty to revv at wil to 6k! lol

Yep I was the same with mine, took the RPM's very gently at first for many reasons but among them were; not wanting to crash...! and feeling a bit strange at the thought of revving a pushrod v8 to 6,000 RPM.

Now some 9 months on and also thanks to my mate and his s2000 I've started employing what I like to think of as tasteful thrashing! hahaha

So nothing too crazy..'til warm - and that's the oil temp not just coolant - M5 ownership showed me how much longer oil takes to reach temperature but yeah, there's definitely another surge like the one you get between 3,000 - 4,000 rpm up at around 5,000.

Yeah they run out of puff, well peak BHP is at 5,250 IIRC so you gotta go at least to there!

I cant say it gives me the impression that it's pointless going to 6,000 though in fact on the rare occasions that my engine lets me (my misfire thread is on here somewhere) I have discovered that they sure sound good at high RPM's!

[Rossco2010]

Well said lads. Gritted my teeth and got on with it at the weekend; went right up throughout the revs.

First impressions? Fook me! Different car driven a bit harder. Lovely!

Cheers

[taylormj4]

bigdods said:

IIRC my 450 has the rev limit set at 6200 , but it runs out of puff at about 5500. But I often take it to 6k just to hear the noise.....

I would call changing at 4k short shifting as its right in the optimum power band, its where I change when I'm not in a hurry.

Lol, awesome! When you're not in a hurry ?! I change up at 2k when I'm not in a hurry, 4k is hurrying but wanting to be nice to the engine, 5k is if I'm wanting that TVR-feeling but never gone past 5.5k. It just sounds wrong, like the engine / car is going to destroy itself. Ha haa, maybe I should just wear ear-defenders. Second thoughts, stuff that !

Can't say that I get bursts of power though as it goes up through the rev range, once above 2k, my 450 just pulls pretty much constantly through the rev range. Is that unusual ?
Matt

[pwd95]

Mine positively tears up to 6k rpm under full throttle. The rev limiter is a real let down quite often.

[900T-R]

I found that my rev limiter is 'somewhere' between 6.5 and 8K when my throttle cable decided to stick at WOT

DISCLAIMER - this is not a standard engine, don't try this at home, no actual engine internals were hurt blah blah blah

[V8FROG]

i like ur disclaimer comment,very helpful

900T-R said:

I found that my rev limiter is 'somewhere' between 6.5 and 8K when my throttle cable decided to stick at WOT

DISCLAIMER - this is not a standard engine, don't try this at home, no actual engine internals were hurt blah blah blah

[.Mark]

Rossco2010 said:

Well said lads. Gritted my teeth and got on with it at the weekend; went right up throughout the revs.

First impressions? Fook me! Different car driven a bit harder. Lovely!

Cheers

[scotty_d]

My 400 would pull well up to around 6k after that it runs out of puff then hit the limiter. Cerb on the other hand very hard to use all revs on the road.

[BillC99]

My 4.0l hits the limiter at 5750. Is that normal? If others seem to get 6000+ maybe there is something amiss?

[blueg33]

BillC99 said:

My 4.0l hits the limiter at 5750. Is that normal? If others seem to get 6000+ maybe there is something amiss?

Range Rover map?