Some recent performance mods

[Jalfonse]

I've been doing a lot of research on the various intake and exhaust modifications and after a lot of deliberation took the plunge and had tuned equal length manifolds, 200 cell Cats and K&N air filters installed by DAE. The exhaust and Cats were provided by Russel at RS Fabs. It's worth saying at this point that there is a lot of good quality kit supplied by other manufacturers, I spoke to most of the well known providers and also chatted with a lot of map-tuners to see what they were doing, all were very helpful. The reason I chose my particular parts was that based upon what I'd learned they had demonstrated the best performance increase, were very good quality (as the others seem to be also) and the key was that they solved the noise problem associated with the 200 cell cats. The noise level when the exhaust valves opened was becoming a real problem for me personally, I'm not sure if it got louder over time or whether I just went off it, but at 4K rpm it sounded like small children were beating an empty oil drum with hammers, very metallic and raspy and something that others said they thought spoiled the car. I didn't want to mess with switches to keep the valves closed etc either, just wanted something more like the standard system with fuse 22 removed which I still think sounds good. The RS solution to this conundrum was to add a silenced centre section/h-pipe which gives the car a completely different (better) and quieter sound, it also seems to add a bit more horsepower in dyno tests but not enough to use that as a buying criteria to be honest.

The K&N filters were something that I'd wanted for a while and so got them installed while David and James had the car.

The car was independently dynoed before and after and with the help of a remap made 40HP and about 55Nm, giving final figures of 426PS and 465 Nm, very similar to a 4.7l car. The Torque figure is the important one (power is simply calculated from the measured torque when the rotational speed is introduced). The torque rises steeply after 3500 rpm (mostly from the 'wave' scavenging component coming into its effective rpm range) and stays significantly higher than baseline right up to the red line. Overall very happy with the service from DAE and RS and would say this is a very effective mod if you're considering keeping a 4.3 Vantage but want more mid range (and above) torque.


[footnote]Edited by Jalfonse on Wednesday 5th November 12:36 pictures to follow when upload works again..

Edited by Jalfonse on Wednesday 5th November 12:39

Edited by Jalfonse on Wednesday 5th November 12:46

[mikey k]

Interesting
Not sure what the "200 cell cat noise issue" is
Though I know mine are a different design the others on the market as I wanted a deeper sound.

[Jalfonse]

Noise levels are very subjective Mikey as to whether you like them or not, I just wasn't happy with the sound of my car so decided to change it, it's just a personal preference, cheers

[mikey k]

Jalfonse said:

Noise levels are very subjective Mikey as to whether you like them or not, I just wasn't happy with the sound of my car so decided to change it, it's just a personal preference

exactly why my cats are different and I have a 4.3 back box
I was just curious to understand what you saw as the 200 cell cat issue

[8Tech]

Its great to see proper evidence of the results of a modification and not just the seat-of-the-pants dyno, thanks for that. Although extremely impractical, it would be nice to see the effect of each of the mods on the engine as sometimes they compliment each other and the sum of all the mods together is greater than the sum of the individual mods.

I am wary of the K&N filters though. Whilst increasing airflow undoubtedly, they can leech filter oil into the mass airflow meter causing problems. They also require regular cleaning to maintain efficiency, and this involves re-oiling, the primary cause of MAF failure.

Great results though, congrats, 10%+ on the horsepower and more than that on torque is a very worthwhile increase.

Edited by 8Tech on Wednesday 5th November 16:53

[divetheworld]

I'd really like to know more about the centre section noise change.
Is it a deeper sound? Less metallic? How loud is it compared to a standard car with 22 removed?
I wish I could hear it!!

Lastly, what did they charge for that bit?

[Jalfonse]

8Tech said:

Its great to see proper evidence of the results of a modification and not just the seat-of-the-pants dyno, thanks for that. Although extremely impractical, it would be nice to see the effect of each of the mods on the engine as sometimes they compliment each other and the sum of all the mods together is greater than the sum of the individual mods.

I am wary of the K&N filters though. Whilst increasing airflow undoubtedly, they can leech filter oil into the mass airflow meter causing problems. They also require regular cleaning to maintain efficiency, and this involves re-oiling, the primary cause of MAF failure.

Great results though, congrats, 10%+ on the horsepower and more than that on torque is a very worthwhile increase.

Edited by 8Tech on Wednesday 5th November 16:53

Thanks for reply Gerry, thought you'd like that. Agree with your comments and I was originally thinking of a step by step dyno of each mod but it gets so expensive and with the travel to and from the dyno and the setup and reporting etc it just becomes so impractical especially since I was so far from them. Understand your points on maf sensor, it's interesting that my car made 20 less Hp than RS fabs proto car and I think that was probably down to difference in maf cal, so if I was bothered enough I could probably extract more power and torque with a further map tweek (but tbh I'm not).

[Jalfonse]

divetheworld said:

I'd really like to know more about the centre section noise change.
Is it a deeper sound? Less metallic? How loud is it compared to a standard car with 22 removed?
I wish I could hear it!!

Lastly, what did they charge for that bit?

Brent, it's difficult to describe in words, but I'll try, it's much less of a metallic rattle than before but not deeper, it's probably as loud as standard setup with fuse 22 removed. To me it sounds more like the v8 mercs. The h-pipe removes the thud from each bank of cylinders by attenuating the first order firing frequency noise. In terms of cost, Russ is updating pricing right now so get in touch, he is at the top end of fabrication capability/quality as evidenced by his formula one work so it's not like getting a mass produced JP silencer for a TVR (which I also liked) , but I think there is a gap in the market for this silencer so he may consider that in his pricing if there's enough interest and you haggle :-)