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MG MGF Technical - DVA full monty
|Has anyone had the 200 BHP version of the DVA conversion on a 1.8i I have a 1.8 given around 155 BHP and find it not very fast and lacks low down power. I would like to make the car very fast even from pull away. Super charge is too expensive. DVA seems to be around the £2.5 Grand mark but I am worried that with all the large valves Cams, etc you use low down torque etc.|
|The Man to talk to is Kingsley who'll be along later, he has the DVA 185+ conversion with MTB Emerald and bit valve head. It was on the RR yesterday so we should find out the results today.|
I on the other hand have the DVA155 big valve kit with verniers and I must say I'm VERY happy. Very, very quick especially initial acceleration, it might lack just a little in torque but I hope that this might be re-gained by replacing the K&N with an ITG.
Mine is on the RR at the 'King Cone' session in May I might suggest that since you're in Essex you might want to come along and see both Kingsley's car and my own for comparison.
Out of interest haw are you managing 154 out of your MPi...
I have all the bolt on's. Cams with veriners, Exhaust, 52 TB, Enclosed with cold pipe K&N 571, Icon unit, Power boost valve, de burred Inlet manifold. Hmmm. That is all I can think of at the moment.
Intersting combination, you might well be interested to see the performance of my car, same spec as your's but with the flowed big valve head. I've just disconnected my ICON, I may re-wire it in depending on whether I decide to plump for the Emerald at some stage in the near future. Out of interest which cams do you have.....and more importantly how did you have them timed, this (as I and Rob have found) is a crutial element.
|The Cams are 280's, Veriers were dialied in when it was installed. |
Would be interested in getting together to see what difference there is.
|Meeting up would be interesting, are you free on the 10 May for King Cone in Thetford it would be good to see your car on the RR too, otherwise we might be able to arrange another time, I'm sure Dr Bell would be interested to see the comparison too.|
Do you find the 280's lumpy in anyway, does the idle give you any problems and do you suffer any stalling after fast runs..... My 633's are running perfectly but before the correct settings the car was a bit of a pig....
Can you give me you email details.
|Again thanks for the intro Tim.|
have the full dva works on mine, went to map it yesterday but shock horror 170.8 bhp was all we could manage. massive problems with overheating (dodgy thermostat) and the aircon kicking in. we couldn't advance the ignition enogh at the top end due to a poor batch of fuel and think the cam timing may be a bit off. so we're going to give it another go after the filter tests next week.
At the moment tho it feels much better with the new map.
FYI mines with 285h cams
It's quite noisy tho, so you'd need to be prepaired for this.
|oh and i think a cr box is needed to get the most from this much power.|
I can make the 10th but need to gat back to Essex Lakeside by 4:45pm.
My email is firstname.lastname@example.org
My car was lumpy on tickover and stalled after coming down from 4,000 revs until I fitted the High pressure Fuel regulator. It is still very very slightly lumpy now.
|Ah interesting. In fact the problem of stalling on the over-run could have almost certainly be cured by timing the cam correctly. As I found when I visited Dave Andrews to have my cams timed it's a very specialist skill with lots of pit-falls for the unsuspecting tuner. I suspect the cams may give you more power with more radical timing but at the sacrifice of the drivability. |
I'm sure Dave Andrews himself will be along soon so I'll defer to his greater knowledge.
I believe that the King Cone event will be starting pretty early in the day so I would see a problem with your getting back to essex for 4.45, I'll get Rob Bell to drop you an Email.
|Kingsley, I am very surprised you have only got 170 bhp. Have you got also:|
4-2-1 exhaust manifold
Multi Throttle bodies with cold air induction
I say this as I know of two Lotus which have DVA fully treatment and both have about 200.
|yes, manifold, throttle bodies and cold air, performance exhast, emerald management, large inlet valve flowed head.|
curve went stright up to 6800 (170.8) then flattened off completely. so something's amiss.
|So it seems like you should have another 400-500 revs of power coming on there, and if projecting the gradient to that point you should be looking at quite a tidy figure.....|
I'm puzzled at the flattening off of your curve, a similar conversion was at Emeralds today, same head, TBs , similar exhaust but it had softer cams and made 180BHP, something must be awry at the top end, I would expect power to peak at about 7600 with your cams, extrapolating the power you have at 6800 and keeping the torque similar, I would expect you to make around 185, bearing in mind the kit is advertised at 175 that ought to be satisfactory. Similar setups in Caterhams and Elises have made between 190 and 200BHP so 170 seems inexplicably low.
Tims observations about cam timing are spot on..
|We're going to do the cam timing on the RR day as people may find it interesting to see how it's done. we'll re-look at the mapping then.|
|Sounds as though the 10th is panning out to be a real petrol heads treat! :o)|
Steve, I'll drop you an email...
Kingsley, who'll be setting your cam timing for you?
I wonder whether the cam belt is adequately tight - based on Tim's experience...
|Rob, Dave W is going to do it in between power runs.|
Cambelt was changed by techspeed only last week so i'd guess it'd be right.
This thread was discussed between 01/05/2003 and 02/05/2003
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