I think the fact that IanBs car made over 200BHP at Stealth using K-Jet fuelling (albeit with a Motorsport metering head?) proves that it is good up to this kind of power figure... Carbs are fine as long as they are jetted & set up properly. Not easy in this day & age! Needs to be 45s on a 2L without doubt. Even then you gain a Few BHP, lots of noise & dire fuel economy...not to mention being tempremental as regards needing "regular" tuning!! Hotter cams will certainly compliment carbs & vise versa as the breathing will be slightly improved... The fact that valvers on K-Jet can make such decent power figures (Such as IanB, GVK, Barny, & Tubs) show that the induction side of a 16v motor is good as standard... Most gains will come from a flowed head, suitable 4 branch/exhaust & uprated cams..
You may find that 1 is up against the rad. If your gonna do it properlly you'll have to chase up a lower rad or get one made up otherwise the airflow is going to be all messed up on one side.
if youve got the carbs,stick with em if you havent,get some in all fairness carbs can equal k jet,torque and bhp wise. and how cant you get more power from fitting carbs? more direct and smoother intake/more available air mass/more available air speed... than the backwards on itself 16v inlet manifold. if theyre in perfect working order they shouldnt need resetting every 2 mins... when i had mine set up on the rollers,i watched a needle on a machine hit a marker that said 140 bhp,which was supposedly @ the wheels. obviously i dont know if it was producing that but it sucked in a few jap motors etc. i dont know for sure if the head had any work or not,was a kr 1800,new 45's,s/sprint 4 branch.
As I keep saying , I hope we get some of you carb boys at the next 16v RR day at Stealth to show us how good these Webers are
Standard Metering Head Chris...tweaked slightly for more fuelling.tried a VW Motorsport item but it wasn't working right...doh...overfuelling slightly When is the next Stealth day ?? Ian
Im there if i get an invite!! I agree that Carbs are ideal for simplicities sake if it makes a conversion easier...just not sure that they deliver on BHP.... Does anyone on the forum run a high spec 2L 16v on Carbs?? i.e Schrick 268/276, 4 branch etc etc. Just wondered how they compare BHP/torque wise t say Barny or Ianb who have similar set ups fuelled by K-Jet..
What about Vick's cars? 183bhp & 162lbft from a standard ABF 2.0 16v running full digifant management? No engine mods at all. Good filter and decent exhaust system is all it has.
The best MK1 on 45's is Jason Bennetts haven't seen him for a while but his is 2.1L 9A on shricks and 45's and puts out 210bhp i'd stick with the k - jet or go for digifant off an ABF
There's nowt wrong with carbs at all providing you have someone who can set them up. They are especially effective on a race motor which spends most of its time at +/- 3K rpm revband - the carbs can be jetted to work here very well - Carvell's scirocco is on carbs and goes pretty well I'd say. Carbs will never be as good as a proper mapped FI system though as this can operate just as efficiently at all revs and loads. Did a calculation when talking to Bill the other day and was quite suprised with results - a 60mm throttle body has area of 2827mm2. 2 x 45mm TB's have an area of 3181mm2 (only take 2 into account since only 2 cylinders fire at once on a VW 4pot). 45 carbs usually have 36 or 38mm chokes in them so if 38mm, area = 2268mm2. I'm not suprised that 45's struggle to make the power that Kjet does (need to double check size of Kjet TB though). Cheers Rob
Nice find Rob, thanks. One of the gains in ditching k-jet is removing the restrictions imposed by the airflap on the metering head I suppose.
With digifant, everytime you need to adjust the map settings for a new modification you have to change the chip. You could use a custom ecu and just remap it evertime you need to change something. Digifant = cheap initially but 350 for each remap. Custom ECU = expensive initially but more future proof for and mods you may do even turbo's etc.
i would have thought that any gains from carbs would be on the pulse tuning side, not extra flow? we need to see matt Ds/MCs stealth runs to see what the k-jet may be holding back
Me & infinity were 'playing' with DTA on his old 1.8l. We noticed a great improvement in low & mid range torque. This might be down to the better ignition advance or more tweekable fuel delivery. It was run with a Seat 16v manifold with single large throttle body. The car wasn't much quicker top end but the mid range was definately stronger. When he went back to k-jet, the car felt laggy & slow.
it would be very interesting to have a selection of 2.0l 16v MK1's on the rollers to see the + & - of each set up. i get 170 bhp and 150lbft with standard k -jet and KR cams with gas flowed head and it runs spot on i prefer the bottom end torque rather than more top end bhp. Edited by: Brookster
