Which to do first??

[pkw2704]

So i think we all suffer a bit from the upgrading  disease,so my question is .I run a 1.8K Xpower 140 with the standard exhaust 4-1 manifold/system which i read strangles the engine.I dont really want to take the engine apart,and wondered if going 4-2-1 would help it breath better with the aluminium plenum and release a few horses,or forget the exhaust and go DHTB to get a bit more.Which route is best ,or is someone going to say i need both(gets expensive then ) What could i expect from each

[SLR No.77]

Start with a proper exhaust, fitting TBs will also involve an ecu and mapping therefore an exhaust as well, whereas you can start with just the exhaust on its own.

You've not mentioned whether you already have a lightweight flywheel? A fairly basic upgrade of exhaust, a lightweight flywheel and vernier pulleys to enable the cam timing to be set properly would make the engine really sweet without the need for major expense.

Stu.

[pkw2704]

should  i see an increase in exhaust alone,read somewhere the standard 4-1 robs 10 bhp

[SLR No.77]

Personally I ignore numbers, it will feel different and more lively with a free-flow exhaust, proper setup and lightweight flywheel. Numbers are for bar room discussion!

Stu.

[David Brown]

Have you seen Dave Andrew's website - DVAPower. Terrific amount of information and advice on upgrading the k series. 

[pkw2704]

yep seen daves page, ok so exhaust first to see if it frees up the engine a little,throttle bodies on my xmas list

[SLR No.77]

Do you have a lightweight flywheel? Verniers?

Stu.

[pkw2704]

no not yet,as mentioned i dont want  really to split the engine or take out the box

[timb2117]

If you're shy of too much ripping apart, consider a K maps ECU - made a nice & noticeable difference to mine.

[Nick Bassett]

Remember, if you go down the TBs route you’ll also need an Emerald ECU and map to power them... plus you’re likely to need forged pistons as you’ll be revving the engine higher and putting it under more stress. Also if you’re going to the effort of TBs you really should port the head to maximise the benefit... and so it continues!!

[SLR No.77]

Without any flow work on the cylinder head, fitting throttle bodies and a better flowing exhaust (plus suitable ecu/map) would give something nearer to "R300 K" specification and should negate the need for the stronger internals that Nick has pointed out.

If this is the route you're intending, start with an exhaust and verniers (or "offset dowels) then fit throttle bodies and an ecu later when funds allow. It's this second stage that involves much more cost.

Seriously though, fit a lightweight flywheel. Removing the engine (leaving the gearbox in situ)  is no big deal. It's also quite low cost before you go down the throttle body route.

Stu.

[TomB]

This is more or less what I’ve got on my home made 1.8k Supersport conversion. I’ve got a race exhaust, verniers, SLR throttle bodies and an Emerald ECU. The engine is mapped at 150bhp on standard pistons. I just make sure the Rev limit is set accordingly in the ECU - I think it hard cut at 7200 or 7300.  But I can’t remember the last time it cut in. In its former guise as a 1.4, I fitted the verniers and lightweight flywheel, which I retained when I did the 1.8 conversion.

Cost effectiveness is difficult to gauge - new exhausts are not cheap! Bang for buck, vernier and lightweight flywheel are well worth doing. Some would say your better of saving for longer and going all in with Dave Andrews - but at the end of the day if your exhaust is strangling the engine, you’ll need to change that anyway. 

[wjw]

I've had 1.8k 6 speed eu3 Roadsport from new. Considered options for many years, then a couple of years back fitted a Powerspeed 4-2-1, had kmaps ecu remap, and Dave Andrew's fitted Piper 633 cams and verniers. Transformed the car, much smoother and more power delivery right through the Rev range. Highly recommended.

@pkw2704 your power is similar to piper 633, but for best advice give Dave Andrew's a call.

also fitted Nitron NTR1 and new springs from Simon ar Meteor. Again highly recommended and made a big difference over 18 year old Bilsteins.

[Golf Juliet Tango]

Exhaust first but bore diameter is probably more important that arrangement. 

I recommend Powerspeed. 

http://www.fastroadconversions.co.uk/

[Seabea23]

I talked to Powerspeed last week, they have stopped doing systems for the K engine. Non standard options seem to be getting difficult to find. Simpson exhausts who were another choice seem to have disappeared.

[pkw2704]

thats been done already, and i agree

[pkw2704]

looked at the caterham 4=2=1 system and box for the vhpd,would this do?

[SLR No.77]

If it's a full system it'll fit any k-series.

Stu.

[Tazio]

Seabea, Simpsons are around, all their info is on Simpsonraceexhausts.com website, the other to consider for bespoke fabrication is Mike Edwards at Wisbech.

 

[Seabea23]

Tazio, thanks for the Simpson link.

[Seabea23]

I don’t think the Caterham 4-2-1 VHPD system has a cat so would be a problem at mot time.

[SLR No.77]

My VHPD system has a choice of a cat or a bypass pipe.

Stu.

[pkw2704]

I'd keep the old cat can for mot time

[SLR No.77]

Do you have any idea about budget?  The upgrades being discussed here will run into £1000s and you might be wiser to swap the car instead.

Stu.

[7 wonders of the world]

Changing the exhaust will also affect the mapping,

K heads respond well to porting as many have poor castings,

Powerspeed I wouldn't touch their collectors are very poorly made

Speak to Mike Edwards, superb craftmanship and secure workshop a whole lot better to deal with than Simpsons

Mike is on 07762 475953

The VHPD system did have a cat, but you can get the bypass pipe for it.

You should rebalance the bottom end when changing the flywheel to so I suggest finalizing a budget and working form that.