R400 refining

[taffyracer]

Just got my car back with its new R400 engine.....sweet as a nut and what I should have bought bought in the 1st place......also fitted the R500 flywheel, new clutch and CRB and it pulls like a train from about 5,500 but low down there isn't that much more than my old VVC......got some Verniers on the way and a remap booked but what other things can be done to maximise the standard set up in terms of HT leads, injectors, spark plugs etc, you know the little things?

 

C7 YUM

[regroo]

If you change the timing you will find that the character of the engine will become very different. IME with an SLR it was always peaky before the remap which changed to loads of drive from 3K up. Not sure what exhaust you are running but if you are looking for more in the middle then a 4-2-1 will probably do well. Unless you are running lots more power then I wouldn't waste money on different injectors.

 

As for leads etc I have always found that the standard kit in good condition is the best place to start. Aftermarket bits and pieces have rarely delivered and extra benefit when I have tried them.

[taffyracer]

I'm running an R500 exhaust with no cat, it's a 4-1 system, i noticed the standard VVC HT leads just don't fit very well at all, can't get the cover back on, just got me thinking that maybe there are better options than OEM, will get the standard injectors cleaned I think before the remap

 

C7 YUM

[Jason Plato]

no point in fiddling with plugs and leads etc. The VVC engine is quite a torquey engine at low speeds - that was the main benefit of the variable cam fitment.

 

The whole idea of producing more power is to produce torque higher up the rev range. So I would not be at all surprised if your VHPD engine is actually producing less torques at below 5000 rpm than the VVC. Certainly less below 3500 rpm.

 

The theoretical max torque for the 1796 cc engine is 172 ft/lb, but your not going to have this across a wide band of engine speed even if you spend £10,000 modifying and optimising the engine to produce this torque.

 

To start the path towards this 172ft/lb you can optimise the timing of the cams with the fitment of adjustable verniers (if your cams are less than optimised already ?), fit a 4-2-1 exhaust manifold with optimal tuned lengths, try some development on the dyno with fitting various inlet trumpet lengths, then change the cams to produce torque lower down the rev range. Unless engine ancillaries are failing then there isn't much to be had with changing them to aftermarket items in my experience(and I have been there with most of all the K series stuff )

 

The ultimate option is cubic capacity, hence why I fitted a 2L duratec and now bathe in the supreme 174ft across 3000 rpm revband 😬

 

 

 

 

here is my Duratec R .... C7 TOP

Taffia joint AO with Al

 

[Jason Plato]

I forgot

 

The other and cheaper option is to change down a gear and keep the engine in the sweet spot above 5000 rpm 😬

 

here is my Duratec R .... C7 TOP

Taffia joint AO with Al

 

[Rob Walker]

the VVC HT leads are 15mm longer than the stock Rover leads to accomadate the taller cam carrier.

[taffyracer]

Cheers Rob/Dave , new standard HT leads on their way.......i know sometimes its best to leave alone but I can't help tinkering and plotting upgrades, i find it hard to resist.......the VVC was a great engine when on cam it just needed more up the top, spent most of my time bouncing off the redline and having to reset the ecu , but the R400 is just sublime at the pointy end, the Brynglas/Bute tunnels were made for this engine, but the map isn't ideal and low down there's a big flat spot and it's also overfuelling, cams are not optimized at all, have some verniers are en route and will get them tweaked when I have a remap shortly

 

Duratec is next on the list

 

C7 YUM