What's the top speed of an NA?

Im surprised you got to 90 Vics

No offence but i think on the VIS models could even get near that speed as i dont think the gearing is upto it...

I've seen 130 in my old GSi. Well you didn't specify it had to be a coupe

If we being funny, my mates 2.0 litre mondy was clocked at 140 on the gps.

Ross

pah, 140+ as the speedo stopped but the revskept rising ni my 19 16v na Also im sure nigels old 355 topped out a bit higher lol but back on topic of 16v and 20v NA's please :P

Lol. Thanks for that mod KP!!!!

Is 140 about the limit for a coupe? Must be gearing as there is loads of cars that knock about the same speed out, but dont have the coupes AMAZINGLY good front end shape for top speed!

Ross

Its gearing as they are geared to be at their best economical performance at a certain rev, this was only changed for the fancy 6 speeders as i dont think fiat were that bothered about MPG for them

As I stated; redline (6000) on the 16v = 129mph. They've had the gearing set for top speed, not best economy.

Neil

I can do that in 4th and then some

Whats the italian speed limit again and what rpm does the coop sit at in top gear at this speed?

i've touched 140 (on a track of course) & i gave up before the car but i do have a poweflow exhaust & chip

KP, you have 52% extra power available, so should expect a (drag limited) top speed about 23% higher.

And lo and behold, it turns out that if an unmodified 143bhp 16v will do 129mph, an unmodified 220bhp 20vt ought to do 158mph.

Does that sound about right?

Neil

the gearing on a 20vt is different to the NA's though. it really is geared to cruising at a lower RPM than an NA from my driving experience of a few coops now.

I've had over 158 so that sounds about right Neil. Im amazwwed that you worked that out!!

ROss

Just had mine upto 128 (seen through gps) But have had the car up to 135 (indicated on speedo)

Have to say that my speedo is pretty accurate all the way to 110 (then i stopped looking at the gps and started concentrating on what was ahead of me!

Also is this self powered as i reckon a working 20vt could tow an NA beyond its top speed

And yip our barnacle is a smart one, he made the widgit for starts

I got an indicated 130-135 (it was between the two and I wasn't going to spend time deciding whether it was 132 or 133) out of my unmodded 20v on das autobahn

KP, whether or not the 20vt could tow an NA beyond its tops speed depends on the drag of the two cars, not the weight of the one being towed. I doubt it, somehow, unless they're *very very* close together.

Glenn, the only thing that affects top speed is whether the engine can turn fast enough. The ECU cuts out the engine at around 6k8 - so in theory, you can still be pushing at 147 mph, provided the engine's getting enough petrol.

But aerodynamic drag - which is the main affect on top speed - is proportional to the square of the speed, so as 143bhp gives you 129mph, you'd need 147/129 squared times 143bhp to get there: approximately 185bhp. If you can get that from an NA 16v at only 6800 revs I'll be very impressed; you might try gas flowing the head, losing the cat, changing the cams to something vicious...

It's also why I was sceptical about Stephen's claims of 147mph... by same calculation, 140mph needs 168 bhp. The 20v is rated at 155bhp IIRC, so an extra fifteen or so horses is more achievable.

And just for the hell of it - a 200mph coupe's going to need something on the order of 350bhp - but that's ignoring other friction losses (gearbox, diff, and tyres, mostly) and the fact that the gearing needs rebuilding to turn the wheels that fast and you'd need a lot of aerodynamic work to keep it stable (and that eats power, too) - and bear in mind that in *all* the cases we've discussed, it's going to need that power available at maximum revs, which turbo cars don't tend to do.

So for all practical effects - since we know there are cars out there with that sort of power that *won't* do 200mph - most of the mods are tweaked for in-gear acceleration, not top end speed.

Neil

Towed cars arent that far behind so i think they would slipstream a fair bit as well...

I thought Matt was geting closer in South africa to 200mph?? I reckon at least 400bhp+ would be needed to get there though with tyres and gearbox's and all taken into effect and god only knows the aerodynamics as well!

thats bloody quick and would upset some porkas and other cars need i say, was he pushing 350 or thereabouts? im sure he had forged bits as well as customer coolers and stuff as well but found the front end got light and had to ease off if i remember?? has anyone heard from him since the forum died?

try around 500-ish with nitrous

For the record my NA has a VIS engine.

bobbs, just go out, give it the bifters, come back and let us know

I know what speed I got but it felt like it could do a bit more, hence my question.

PMPL @ ed!

Well it was on a private strip just for testing top speeds and it did an indicated 135.

Which sounds about right...

Edited to say: I just found a spec that suggests 154bhp and 132mph.

Neil

According to this 132 for the non-VIS, 135 for the VIS model...so I wasn't far out with 130

http://www.fiatcoupeclub.org/forum/showflat.php?Cat=0&Number=1004&an=0&page=0#Post1004

They do feel like they still want to go at that speed though......

Did 132 through the gates at Mondello..v late 20v VIS which seemed a lot quicker than standard..possible to chip NA's?

Mines a vis - hit and verified by Duke748 in his LE at 144 on clock - both of ours - so give or take a bit on that....

anyway - its fast enough to kill ya...

cheery thought.

My 20v non VIS is quite low geared in 5th and is not a cruising gear, around 4k at 80mpn. Can believe that it would do just over 130mph. For a N/A it flies when it is pushed over 4k revs. I sometimes drive a Bravo HGT as well and The coupe feels quicker and handles better as it is stiffer. Not just my opinion but the HGT owners as well... We have both swapped cars before. It is on the cards to get the HGT's suspension tweeked. Whether the coupe feeling faster might be just a feeling of being low I don't know but we will shall be placing them against each other and have a few 0-60 40-100 runs.