i am hoping anyone with knowledge will take time to explain what ever they can on this thread to help explain what makes a good 1/4 mile car
this is not about suspension and tyres etc just engine and in a coupe at that
turbo choice has to be the biggest issue
do you want quick spool?
pure out and out power?
opinions
turbo choices backed up by explanations would be apreciated

just to elaborate as a starting point forged engine stage 2 or 3 head the usual mods (pro alloy 5stud 3" etc)

I would say as smooth power as possible rather than all of the power at once violently is quite important on a fwd car, along with low weight but also having the weight in the right place.

Start with less power and try to find the right setup suspension wise by making small changes, then gradually up the power once you are used to it and have the knack of getting a good launch.

Re turbo choice, im unsure, but sure others on here will have advice.

thats what i would have thought so i would think a .64 housing on whatever turbo for that reason and for quicker spool i suppose..the trouble with gradually getting it right is i still have one turbo choice and one mapping so although i can get a bit of practice at lower boost settings ..financially its a one set up got to get it right first time job

It's quite simple...the more power you have the better the quarter mile time will be. Therefore you want the biggest turbo possible. Why would you want quick spool up on a drag strip? That's a new one to me.

As long as it isn't supidly big where you have a really narrow powerband, then you're going to be on boost throughout the run which negates the need for a fast spoiling turbo. A higher rev limit will also help, as will saving weight.

Use an AVCR to lower the boost in first to limit wheelspin and that is as good as it's going to get on a coupe.

quicker spool i mentioned as a by product of the .64 which i had thought would give me smoother power and a wider powerband..
but i am asking for help and explanations as i have no knowledge in this area at all, i also have to give some thought (although not too much) to the fact that its also my road car
in that case it would seem that the .64 would not be needed and a 2871r (the biggest) or 3071 are the only option
so i have learned something already as i had thought the smaller housing on the 3071 the way to go

Depends how much of a 1/4 mile car you want? A proper turbo charged car for the strip needs to be able to hold the engine under load at the start to build boost to get on with it quick when it's time to go. Either holding it on the convertor of an auto box or in a manual an ALS system. Big turbo for a dedicated car (way bigger than you think) being as you'll never drop below decent rpm (lets imagine 4500 rpm)and some clever boost control. 1/4 mile machine would likely suit a water to air charge cooler, fully iced down. BIG slicks at the front and bars to hold it flat.
Something along the lines of this fella. One thing for sure is that there's a whole heap of effort/expense to do it well. http://www.youtube.com/watch?v=gF8RIqgP1j8&feature=related

what i probably should have said is how to maximise the 1/4 mile potential of the car i am or rather someone else is building for me ...which will be my car to use maybe not daily but weekly
for sure there are a few cars like nigels etc out there but i thought if i gave it thought at this stage i could maybe maximise the cars ability in that area rather than just build a big bhp job and hope it can do a quick 1/4

maybe thats my only option

Just slap a GT30 based turbo on it and build a massive intake and exhaust system, that'll do the job.

You could strip it out,spend some money on another set of wheels with slicks fitted, research gear ratios, specifically ask the tuner to map for the purpose of 1/4 mile and spend some time playing on here just before you roll up http://www.speedwaybids.com/trees/tournamenttime.php

Whats the nature of the engine you want to build?

i have 83 ml accralites and farndons .it'll have a stage2 or 3 head.. probably standard cams as i dont see the expense of c+b cams worth it on a forced induction and when you see what turbo j did with nicks with standard head and cams...., it does seem a lot of money for little return .. then theres the timing up issue to get the best from them
i have eldinhos turbo which is 170353093420 on ebay (sorry dont know how to do a link) but thats the spec but i may have to sell it if its not the right one for the job and find a .86...i have eldinhos 3" exhaust as well ..the usual supporting mods aquamist, walbro, pro alloy fmic and sip,apexi filter etc..
i thought the turbo a good one as although it only has a 2.75 intake and a .64 housing its still rated 480/500 depending on whos figures you read..i looked on garrets site but not understanding the comp maps i cant make turbo comparisons and get any real ideas..my thoughts had been smooth power with this and as i mention before the earlier spool is a boon on the road

Well certainly you should end up with a solid engine with some nice bits, are those the higher Cr pistons?
I'm afraid 20v tech isn't something I know much about so can't really have an opinion on the cams, I don't know what the standard cam numbers are, if anyone has them I wouldn't mind seeing them. The C&B cam (only one to choose from is a shame eh)looks to have decent numbers but maybe the oe isn't far behind.
I'd leave the turbo as it is and spend any spare money you might have on pipes in and out of the engine, if you max the turbo then's the time to buy a new one. Saint knows his way round compressor maps if you need help he's kind enough to help I'm sure but for now it'll be fine, you've plenty other things to do. It's not too expensive to later swap some housings around.

yes it is the higher comp pistons.. will i need to remap if i swap housings later?
when you say pipes in and out what am i needing to achieve with that oor should i say what do i need to do to get the best from it

The ONLY way to get a car to go quickly on the quarter is to have lots of power, as little weight as possible and as much grip as possible

The Coupe is an utterly awful starting point, as power isn't easy or cheap to extract, weight is excessive and the engine drives the wrong wheels

A Coupe is more about stylish speed than excessive speed

Its been mentioned on the TOTB thread that the ony way to get a FWD Fiat to do well on a quarter is to do what the Vauxhall boys do - fit a big turbo engine into a lightweight car

So - 500+ bhp in a Cinq, Uno or Punto and you'll be into the elevens. Add another 200bhp to break into the tens

And it'll still be a little FWD Fiat, in exactly the same way as Specky's mental Tigra is still just a Tigra (quick though - it got to over 170 in the same distance as mine took to reach 150)

i am not expecting to compete against these cars but would like to be one of if not the fastest coop is all..
i would have bought a different car if it was about just 1/4 mile end off
i just want to make this one as good as it can be as i will be trying at various events and will try totb next year.
you had a good third so if i do what i can at this stage maybe i can be as competetive if not more so.. with luck and the right bits now who knows

i feel a fibreglass bonnet coming on

In that case - go for it - I'm done with my Coupe trailblazing days now, so it will be nice to see someone else trying new stuff and pushing a few boundaries

The only thing I would say is not to lose sight of what makes the Coupe what it is - its style - it would be easy to go fast with a 20vt lump in a Uno or similar (OK, not actually easy, but you know what I mean)

However, despite only coming third on Sunday, the day was made worthwhile by one of two Honda drivers that beat me - he said "how on earth did you make a Coupe drive like that? - I thought they were crap" - I simply replied that it took a bit of perseverance and a few quid, and that they were never crap, just misunderstood.

good job im happy being the underdog! but i will happily try and take it as far as i can..i think the 3071r .86 may have been too much in the handling course..yours would be as slow to spool a turbo as i would want for that if you know what i mean.. eldinhos i would think to be about the same ?? have you been in his car?

no - not been in Mark's car, but mine will be marginally faster spooling, due to its slightly smaller size turbo (same turbine housing though)

"yes it is the higher comp pistons.. will i need to remap if i swap housings later?"

Sure thing, your choosen tuner will see a few quid from you if your serious about a fast coupe.

"when you say pipes in and out what am i needing to achieve with that oor should i say what do i need to do to get the best from it"

Provide the straightest and most simple intake pipes in 3" (or bigger if you like) and ensure that at no point after it leaves the turbo the dia is less,try and provide as much charge area in the intercooler as you can. Same goes for the exhaust but don't be shy, bigger is better. Exhaust manifold follows the same principles though not obviously the diameters

If it means moving parts about to make it more simple do as much as you can afford. Custom exhaust manifold should be the first focus of expense. The rate you go through coupes shelve the weight saving for when the engine is good and then fit it to bare rolling shell you'll likely source cheap, then you'll be going some.

No. You want ALL of the weight you have over the front wheels. Shaving 100kgs off the back will probably make a bigger difference than 200kgs off the whole car evenly split.

A light front end will just make you spin more. As poor as coops as for drag cars, they do have the advantage of a considerable percentage of weight on the driven wheels (68-70%).

everyone i know with big bhp coupes have used the standard manifold as theres nothing else really available.. i have a stainless but none as yet have proved to be any better than the standard..i have 3" down pipe etc as you would imagine and 3" exhaust..
on my last project jbt went under the radiater with the pro alloy pipework instead of standard along the bottom..and it cut a good few feet out but was real low with the eibachs.. i never caught it though so maybe even with my coilovers i will do same again does this help?

Mostly tubular manifolds are not what they should be or maybe thats better written "could be". Market says ease of fitment though so can't expect anything different, some of what is available is very nice but who wants to be nice

You got a point ! right one. Not a very light bonnet has to be your first concern,but the weight that sit in the back of front axle...like rear screen (plexi) ,doors bar, rear axle (a lot of weight...I think is possible to pull out about 15kg), rear wheels and tires, side windows, fuel tank (move a small race one, in the place of standard intercooler), steel behind of rear seats.
The bigest enemy of fiat coupe fwd drag performance is weight ! another one is very limited dimension for front tyres/drag radials .
PS: Somebody here tried 225/50/16 or 245/45/16 ? how restrictive is for steering? (for drag is not important,but to reach the location ...you'll need steering...more or less ..:D)