Uh oh, I can feel the upgraditis coming on

[hufggfg]

Well, I've had my R400D coming up for 18 months now and have done around 3500 miles in it with 4 or 5 track days (I certainly wish it was more!). I still absolutely LOVE it, but there are a few things that can be improved (/must be solved).

1) Too noisey - Unfortunately I was black flagged at Brands Hatch at the end of last year because it was too noisy... (a solution here is already in the works).
2) Not noisy enough - As loud as it is, I don't find the racket is makes all that exciting. The Exige S I used to have popped and banged on the overrun, really had a lot of character and sounded like a mini le mans car from the 80s, it was great.
3) Throttle response at the bottom end isn't quite as sharp as I'd like.

So, point 1 is being addressed by getting my hands on (apparently) Raceco's last Caterham exhaust, which will be lighter, quieter, and is re-packable so should solve the issue long term.

For 2 and 3, the obvious solution seems to be individual throttle bodies. From my understanding the Caterham roller barrels don't seem like best solution, both because you don't need roller barrels unless you're going for absolute max power, and they're expensive for what you get (unsurprisingly from an OEM).

So, I have had a brief chat with Raceline about using a set of their 45mm Jenvey ITBs, I'm waiting for them to come back with pricing. If I go down this route I'd get the car mapped by Steve at Track and Road (I've been recommended them by everyone who seems to know anything about Caterhams).

So some questions for the group wisdom:

- Does anyone have a similar set-up to the above? Thoughts?
- Am I still likely to have problems with noise if doing this (likely this time from induction rather than exhaust)? Does anyone know of a slip-on type airbox I could use with the ITBs (I would only really want to use it for track, and not for road)? The one advantage of the Caterham set-up is that they do sell the Carbon airbox.
- Any other suggestions? I want to keep it drivable for the road, wouldn't mind gaining a bit of power, but ultimately really want to solve the 2 "problems" listed above.
- Should I just man up and get it supercharged?

[DCL]

I went the Caterham (Cosworth) roller barrels route and it was the best £2k I've spent. It is a bolt on solution with no mapping required (new map included in the price). The Caterham MBE is locked so it won't be a starting point - either a new 9A4, or you re-flash the old unit and there are mixed opinions as to whether that is possible on some of the later cars.

Advantages of going to throttle bodies is that it opens the possibility of honing your map over time. I suspect the costs will be more than Caterham's kit (just from my experience of the little things that crop up that you never thought about: injectors, throttle linkages, etc, etc )

Good luck !

Edited by DCL on Friday 7th February 14:17

Edited by DCL on Friday 7th February 14:18

[hufggfg]

Whilst I totally get the advantage of a bolt on solution, I never like the idea of a pre-made map when you're talking about tuning a car. It's fine for an entirely unstressed car, but when you're actively looking to improve it an obvious solution is to get a custom map that will actually be most effective for the engine you have.

Track and Road do a lot of official work for Caterham, so can work on the standard locked ECU, so not only are you getting the probably the best guys in the business, but you don't even have the expense of a new ECU.. win-win.

Get your point about additional costs popping up, but hopefully with Raceline providing all needed parts, then a map from T&R there really wouldn't be anything else needed...

[DCL]

I wouldn't belittle the Caterham map. It was the result of many hours, if not days, mapping by Caterham (Cosworth?) on the dyno. The rolling road sessions I've done suggested it is pretty good. If the barrels are set up properly and timing is adjusted correctly, then you will struggle to do better. If, on the other hand, the setup of your engine is not 100%, then a RR mapping session may well improve things, if not the final power figures.

These figures are wheel HP!

[rubystone]

Who are track and road? Is that Greenauld?

[mic]

Its worth remembering that if you decide to sell your car, the Caterham set up is a recognised upgrade. Its well proven and the map is very good. Steve Greenald will obviously be able to fine tune it but not sure you would gain much.

[coppice]

The RBTB upgrade from Caterham transformed my R400; feels a LOT more powerful than before . Far more responsive and utterly fantastic noise- induction howl and wonderful pops and bangs on overrun. Don't believe all the nonesnes about how thirsty it makes the car- it'll still do 30mpg+ on long runs but obviously far less on spirited blats and track days

[k20erham]

Hi despite repacking my btb silencer my jenvey itbs still get me black flagged at brands with a foam filter fitted, put an airbox on and a lot better but very close, they even pulled me in and pointed out I had flames from the ex on flat upshifts and on the over run!!! Fingers crossed

[hufggfg]

Thanks for the opinions guys. Maybe I didn't explain what I meant well. I'm sure the Caterham map is great, but with any engine having a custom map is always going to be the way to get the best out of it.

It is a fair point about the Caterham upgrade being "official" and therefore probably better for the value of the car.

Does having the Caterham airbox on change the performance at all?

[k20erham]

Yes in most cases,changes do usually make a difference,and sometimes you gain in an area and loose in another with one change.rather depends upon how near you are to the combinations limitations,as in another thread CC cannot develop the 620r and get it around a couple of tracks without issues, they have no excuse,£50+k and you have to cross your fingers?and or find that the true cost of noise control is to be down by circa 30bhp I suspect not many will want to share WHP figures when they sort it to be legal and trackday compliant,hope we all get to know.

[hufggfg]

Yep, fair point, adding the airbox probably has some impact... Anyone any idea how much?

Surely at the point it's have much impact at all, you should really have a separate map for when the airbox is fitted?

[k20erham]

Hi despite repacking my btb silencer my jenvey itbs still get me black flagged at brands with a foam filter fitted, put an airbox on and a lot better but very close, they even pulled me in and pointed out I had flames from the ex on flat upshifts and on the over run!!! Fingers crossed

[hufggfg]

Interesting, thanks. Given your car's state of tune I would think my standard R400 with Raceco exhaust and ITBs wouldn't been too much trouble, but we'll see!

I have to say I'm edging towards the Caterham solution as a simple proven out of the box way of doing it. Whilst I'd obviously prefer a custom map (or 2 custom maps, one for airbox, one without), it seems that its going to be much more difficult to do things that way, and whilst I'd love to have the time to source required parts, put it together myself etc, I unfortunately don't have time.

[DCL]

There is a MAP (manifold air pressure) sensor on the air filter box so it should sort out the difference between foam filter and box. As said earlier, the Caterham map is a well developed product.

[hufggfg]

DCL, totally get what you're saying, and right now I think I'll prob go down the Caterham upgrade route, but I just think a custom map specifically made for your engine on a rolling road, by an experienced person, is always going to be better than a generic map which has been worked out for a manufacturer to be able to put on any car they come across, regardless of age, engine wear, other minor mods etc.

I have to say I'm not experienced with MAP sensors and the impact etc, but again my guess would be that it applies some generic changes which are roughly appropriate given the manifold pressure changes, but still is never going to be as good as a custom map for each scenario.

[kenno78]

DCL said:

As said earlier, the Caterham map is a well developed product.

But a custom map would have sorted that blip at 3750-5000 where it runs a bit leaner. Your torque and power curves drop a bit as a result.

[_Neal_]

I agree with Kenno and hufggfg - in my view it doesn't matter how good or well-developed a generic map is, a map specifically tailored to an engine and applied by an experienced operator is the way forward. The generic map just can't take minor mods and natural variations between engines into account.