best mods for the 4.2
Discussion
You can't improve the 4.2 by much !! Cone filters just make it sound noisier
0-60 of the 4.2 is 4.2 secs, an on song 4.5 is 3.9, a measley 0.3 of a second quicker.
These aren't EVO's where you just bolt a gizmo on and your bhp increases by 100! It was already a high performance race engine when it left the factory.
0-60 of the 4.2 is 4.2 secs, an on song 4.5 is 3.9, a measley 0.3 of a second quicker.
These aren't EVO's where you just bolt a gizmo on and your bhp increases by 100! It was already a high performance race engine when it left the factory.
jensena said:
There isnt a lot of scope for improving the 4.2.
The truth of the matter is that the 4.5 boys just have to spend the money to get them to go just that teensy weeny lil bit quicker than the 4.2
The truth of the matter is that the 4.5 boys just have to spend the money to get them to go just that teensy weeny lil bit quicker than the 4.2
Much, much quicker at any point in the rev range, low down torque and power, mid range or high end torque and power, a 4.2 wouldn't get near. Std 4.5 v std 4.2 then there will not be a lot in it low down (0.3 sec), but once rolling at say 40mph and then both putting their foot down then the std 4.5 would gradually start to pull away.
Jules.
Edited by Cyclone1 on Thursday 27th July 06:53
I don't know how good the manifolds are on the 4.2, but if they're the same as the 4.5, there's room for improvement there. You may not gain that much peak power, but you ought to be able to pick up some mid range torque with equal length primaries. That aside the 4.2 is very good as standard.
Steve.
Steve.
You can get the induction manifold cleaned, there is a lot of crap off the castings that restricts the air flow.
Also fit free flow air filters, the cone ones are ok, and as they dont clog up after 30 seconds ala standard air filter they will increase performance. You could also fit link de cat pipes this is supposed to help a little as well.
You will gain the biggest performance increse when you change the suspension and the brakes.
I have had most of the above done just linked de-cat pipes to go
and a good rolling road tune which is happening next month unless Joo has forgotten.
You will not really notice the performance difference with the above because your only adding maybe 5-10max BHP with each mod.
I will let you know what it produces on the RR. I have no idea what it kicks out at the mo.
All I can say about the difference in performance between the 4.2 and 4.5 is at Elvington nobody and I mean nobody came passed me on the two mile straight
including the (at the time) a new Tuscan who had a couple of car lenghts on me out of the corner and at the braking point was more than a couple of car lenghts behind 
When tuned however the 4.5 will be a lot quicker than the standard 4.2 (b&*%$r)
Good luck and keep us informed.
Paul
Also fit free flow air filters, the cone ones are ok, and as they dont clog up after 30 seconds ala standard air filter they will increase performance. You could also fit link de cat pipes this is supposed to help a little as well.
You will gain the biggest performance increse when you change the suspension and the brakes.
I have had most of the above done just linked de-cat pipes to go
and a good rolling road tune which is happening next month unless Joo has forgotten. You will not really notice the performance difference with the above because your only adding maybe 5-10max BHP with each mod.
I will let you know what it produces on the RR. I have no idea what it kicks out at the mo.
All I can say about the difference in performance between the 4.2 and 4.5 is at Elvington nobody and I mean nobody came passed me on the two mile straight
including the (at the time) a new Tuscan who had a couple of car lenghts on me out of the corner and at the braking point was more than a couple of car lenghts behind When tuned however the 4.5 will be a lot quicker than the standard 4.2 (b&*%$r)
Good luck and keep us informed.
Paul
Windsor, I am hoping your newly rebuilt and fettled engine will be a peach and should quite easily put a few std 4.5 to shame. A std 4.2 and std 4.5 showing approximately the same power (bhp) normally results in the 4.5 having more torque, they also have a different type of power delivery that will ultimately result in the 4.5 having the edge. The best thing about the std 4.2 is that they tend to make close to their quoted factory figures whereas the 4.5s don't, this results in the majority of 4.2s making between 325-350ish bhp whereas the 4.5s make anything from 320-365bhp, which is miles off the factory quoted figures.
The standard filter is fine for both the std 4.2 and 4.5, the only problem with it is that it starts to lose it's flowing capabilities as it becomes dirty and clogged up, keeping it clean is very important. There is now an alternative filter available that has more flow capacity than the std one, it will still need cleaning but as it has a greater surface area it will not require cleaning as often, this is a direct replacement for the std filter. I am not a big fan of the Cone Filters bolted onto the end of the two airboxes as I firmly believe that they will lose you power.
The manifold could definitely be a restricting factor, but as yet no-one has mass produced an alternative that shows definitive gains in performance. There is not a lot of room at the side of the engine bay to design the ideal manifold but there is room for improvement, especially if you go down the bespoke route, however, this is likely to be costly and the gains are potentially unproven.
Jules.
The standard filter is fine for both the std 4.2 and 4.5, the only problem with it is that it starts to lose it's flowing capabilities as it becomes dirty and clogged up, keeping it clean is very important. There is now an alternative filter available that has more flow capacity than the std one, it will still need cleaning but as it has a greater surface area it will not require cleaning as often, this is a direct replacement for the std filter. I am not a big fan of the Cone Filters bolted onto the end of the two airboxes as I firmly believe that they will lose you power.
The manifold could definitely be a restricting factor, but as yet no-one has mass produced an alternative that shows definitive gains in performance. There is not a lot of room at the side of the engine bay to design the ideal manifold but there is room for improvement, especially if you go down the bespoke route, however, this is likely to be costly and the gains are potentially unproven.
Jules.
Edited by Cyclone1 on Thursday 27th July 21:02
Touching Cloth said:
Anyone know how a 4.2 might take to some Nitrous?
Something I have been musing over .... just for fun and special occasions you see
Something I have been musing over .... just for fun and special occasions you see
According to my last chat my indie, rather well
It would be purely to help breathing at high altidues in Europe you understand and would not be used at sea level in the UK at all, honest... 
I have fitted 6 pot calipers and nitrons to my 4.2 and they made, i beleive, more of an improvement than cone filters and pipes. At the recent track day at brands i could brake later and get around the corners far better than the standard set up and i think i was as quick if not quicker than some 4.5's. Certainly the performance of a 4.5 did not show around brands with its short straights.
Best couple of grand you could spend!!
Best couple of grand you could spend!!
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