with a spec like that I reckon you should really be going for TBs it would be possible to turn your carbs into TBs with a bit of work and it will just be so much more tunable its covered in one or more of the articles that I'll find for you at some point
I'll second what Tub says about the flywheel, I've got the same one. Mine revs *much* better now Used to struggle after 6k, was singing round to 7k easily at Donington last week
If I was going to the trouble of fitting a fully mappable ECU and everything that goes with it I'd rather spend the extra money and buy a set of 50mm DCOE or DTH ITBs. A good second hand pair of DCOE 45s will fetch 300+, more if the bellmouths, filters, manifold and linkage are with them. Even a converted pair of 45s will only have a size of about 43mm at the most.
cheers m8 thanks gvk,lightened flywheel is a definate,i *think* with the rpm ill be hitting that maybe the slightly heavier than 3.3kg may be better? cheers again m8 seems as though ill be needing 50's,call me stupid but id like to stay away from bodies... how much are we talking for second hand 50's and would they go on the manifold ive got? maybe i should be looking at the ford sites... just a shame as i bought the whole kit new for 1k! [:^(] Edited by: riley
Think you'll find Hotgolf's got a mate with a 2.1 16v on 48s and 300 degree cams that runs 8000rpm with the same flywheel as we use Edited by: G_V_K
Flywheels weight doesn't really have to be OTT with lightweight internals aswell remember. It'll want to be double dowled at least. While this is being done, if you want to use a 'proper' motorsport clutch, like a quater masters (who make nice lookin items) you'l probally want to get the holes drilled for that.. That needs ot be done before treating the crankshaft in any way really, especially if it's tuftrided because you probally won't be able to drill the holes if it is Makes it SUPER hard. Riley, stick to the carbs. They'll be fine, It will just make the engine slighly less tractable and less fuel efficient. The mapped ignition will make the world of difference.
thanks m8,i really do wanna stick with the carbs... could you explain the flywheel bits a bit more? please i was thinking of using a 6 puck paddle?? neil. Edited by: riley
I can't see why you would want a heavier flywheel for higher revs Integra Type R's have massivley light cranks and flywheels. Formula 1 cars have paper ones...
Yea but tubs he's not building a formula one car, and his car isn't a integra type R. Basically the flywheel needs to be located onto the crankshaft in some other way other than bolts ideally. So, drilling holes in the end of the crank where flywheel meets, put some metal 'pins' (proper name dowles) in it, usually around 6-8mm in diameter, height depends on the flywheel really. These then locate into holes made in the flywheel.. It's pretty tricky to do as they have to be so tightly fitted in there. Just helps flywheel stay where it should.. Send the inlet manifold off to blydenstein aswell, i've seen him make alterations to manifolds in the most obscure places youd never even think of, thats made stupidly huge differences. It just isn't worth assuming it can't be made better. Edited by: madmk4
cheers,i understand what you mean now,just for extra holding power i guess,i can probably sort that job myself then how many dowels would you reccomend? 2? 3? cheers guys. edit:should the clutch im after be ok? and yep the inlet(carb) manifold will be sent with the head. little info from chrisp... Edited by: riley
GVK and Tub are right about the flywheel, but I didn't explain my point very clearly. The car - in terms of performance - will be quicker to build speed and rev faster the lighter you make the flywheel; this is quite obvious I s'pose, as the engine requires less effort to bring moving parts into motion (you can gain a similar effect in areas other than the engine, such as very short gear ratios, magnesium wheels, carbon brakes etc etc). What I meant (and it was as clear as mud ) is that, even if setup well, the torque in your engine will be up high. It has to be to make power. If well setup, the torque spread is very, very good (I know that at 3,200rpm, I have about 35% more torque than a stock ABF and under 2500, it's similar to the stock motor and won't get any better I don't think), but the strength of the engine up top (torque wise), assuming it is breathing ok is really big. If you are rolling along at about 6500rpm and release the throttle, then plant it again, the car lifts up with all the torque. The longer you wait, the more inertia (energy stored within) the flywheel loses. The heavier the flywheel is, the longer it will hold inertia for, so if it is too light, when you back off the throttle at 6500, you can drop 1000rpm blocks in a flash. Admittedly, there's still heaps of torque lower, but on my motor (which is what I'm basing this on), the feel of the engine at this point is nowhere near as good, so I try to make sure it hangs around the high revs. I've found in cars with really light flywheels (they weren't VWs but same principles apply) on very tight roads, with a narrow torque band, they're slower than if the flywheel was mildly lightened, as it's virtually impossible to hold the engine in the 'sweetspot', which is usually pretty small. I've forgotten so far, though, that you're doing this in a Mk1 so the car will need less effort to move anyway (well at least compared to my sound-deadened cargo ship!) I'm pretty picky, but you just can't beat riding along on peak torque as there's no other point in the motor that 'feels' so good
h8sv8s ive read your reply a few times now,but i think i get what you mean a heavier flywheel drops off speed slower,so its easier to stay in the power band sort of a bit less like an on/off switch. weather ive understood or not,cheers anyway yeah vick im definately leaning towards using blydenstein from what i know,its gotta be worth it
Have you looked/thought about going big valve? H8SV8S - i see what you are saying now. Whilst i still don't agree with it 100% from experience i know what you are saying. If you are knifedgeing and lightening the crank, pistons, rods etc then you obviosuly wouldn't need to take as much off the flywheel. Edited by: Tubthumped
bigger valves m8? never even entered my mind! i was pretty sure you couldnt go any bigger in the 16v head? or am i talking sh1t?
"Fast road" tuners don't do it but it's certainly possible. Grant Motorsport offer it and Blydenstein would do it if it was needed.
whoa,i didnt know ?!?,cheers anyone got some current/possible valve sizes to throw in the mix? something i can discuss with who ever does the head.
And as said somewhere it depends on your application. If your using it for track use and high revs get the weight off the bottom end and the valve gear. Will help the overall repsonse of the engine. If you're gonna be using it everyday then you'll need some kind of compromise. But if you think a car running 48-50mm carbs on a daily driver is a good idea.....its not. As GVK said, I have a mate running a John Jones 2.1 16v with JE pistons, modded rods, deisel crank, motorsprt head, 48 dellortos, and some 300 schricks, lightened/balanced and all that. Its just been rebuilt mainly due to him 'running around' as a daily driver. An engine of this spec isn't intended to twoddle around the streets and inevitable he's coked the bloody thing up. He complains that it rattles and loses oil. Thats thanks to forged pistons which are designed to expand with heat to take up the extra clearance needed for them. If it's not fully warmd up, then then do rattle about and pass a bit of oil. Solid lifeter head, that too is a bit noisy but allows the car to rev higher than standard. Not really necessary with milder cams although hydraulics do wear a little with high than standard duration cams being used in a seasoned track car. The carbs. Well, they sound like they'll suck the skin off a pre-chopped Jew. The sound is awesome, but the down side is that they are chucking in alot of fuel(when doddering about) which ends up not being burned unless the engine is being used. Fuel economy isa thing of the past. This is all about the driving experience and not the small issues of a daily driver. Hope this is of some help. Some might disagree with some or all of this, but it's 23:54 and I'm pretty much legless
