20VT top speed

Hi all.

First of all, my coupe is off the road still as i'm sourcing parts for engine rebuild + everything related to make the car faster. I hope to complete everything within 12 months from now (it all just costs too much). Aiming for 400bhp and posting this thread to prevent problems. So speak up if you have anything important to say.

To the point.

We have this 1 mile top speed race here, held annually in the beginning of summer. Coupe would classify in B category which is up to 4000cc NA cars or up to 2300cc boosted cars.
So far the best runs for this class have been Nissan S13 and S14 with SR20DET i believe. They manage around 255-260km/h on a 1 mile strip (airfield). In 2005 they also had one crazy finnish guy here who ran 284km/h on a modified old fiat but i try to ignore this fact and hoping he will never compete in this race again
As the coupes stock top speed is 250km/h, I was wondering how quickly the car can achieve this speed? I never tried my car sadly. I got it up to 230 sometimes and it was reached quite fast but i never read the meters it took
So I assume a modified coupe with around 350-400bhp would defo break the rice cars? or what?

What limits coupes top speed at 250km/h (155mph) ??

255-260 km/h by S14 SR20DET (modified, dont know the bhp) achieved his top speed about exactly at the 1 mile marker reaching the cars top speed limit. I assume 2008/2009 results will be similar the one ones before due to this fact. Maybe not, but i will take that 260km/h as my lowest target anyway.
Coupe will run on VEMS ecu and stripped about 50kg.
My car is from 1997, 5spd.

Hi,

One other garzy from Finland .

You will need +400 bhp to get over 260 km/h. Last summer I got 264 km/h in 1 mile. My friend with +300 bhp got 246 km/h.
Stock Coupe has only one limiter to that given 250 km/h; lack of power .

Few years ago, when I had a stock car with only Digitec chip installed (257 bhp), I could get only 224 km/h in 1 mile strip.

Coupe has a great benefit of its aerodynamic shape.

- Jari -

Thanks for the reply Jari, greatly appreciated. What power are you running now? What mods have you got? 264 is a nice combination of numbers
I also assume the zender bodykit would make a difference and 18inch wheels at high tire pressure?

We have an interesting comparison here

My car is running about 400bhp - at Ten of the Best last year, the top speed run was exactly 1 mile from a standing start. I managed 158.9 mph (255.7km/h)

I was well stripped out (at least 75kg removed)

Hope this helps

Measured 408 bhp / 1.32 bar boost.
On that run my Apexi showed all the way up to end 1.5 bar (it can be seen in a video, which I made from that run), so in any case above 400 bhp.

Look the Hall of Fame, my specs can be found there. http://www.online-presence.co.uk/_coupe/

- Jari -

Thank you for the info Nigel. This is starting to worry me now
What turbo are you running? At what boost?

This now looks like I will have to use one from GT30 range.. gonna be a bit more expensive but doable i assume..
But then again, to achieve full boost revs have to go up a bit which is very very bad for me as I plan to use the coupe for everyday driving also and 75% of it would be on city streets GT30 series will suck dck at that.. and i'd get 10mpg probably
Any suggestions?

I use my car daily , no problem with GT30.. turbo nor with paddle clutch. I live in area of Helsinki, so there is traffic jams enough .

- Jari -

Nigel runs a GT2871 with 0.64 housing at 1.5 bar boost. You could go for the same but with a bigger housing for another 20 bhp.

If you want over 450bhp from the 2 lr engine then you'll have to go GT30 and accept that you wont be on boost until after 4,500 rpm depending on your other mods.

What's the full spec of the engine that you are planning to build?

I plan to use Pauter rods together with CP pistons 82,5mm.
Clevite77, ported and flowed head, bigger injectors, custom intake plenum, some other stuff that i can't remember at the moment.
I already have custom fmic with piping, large Green cone filter, custom 3'' downpipe with full 3'' exhaust.
Turbo decision remains still, i'm thinking gt30 now..
This managed by VEMS should show a nice number i think..


another thought:
I think i have to save up and buy that 2,5 engine.. and then cheat in the competition cos no1 knows i have 2,5 not 2 lol

With that spec then the world's your oyster - you just have to decide what kind of powerband you want...

That wouldn't happen to be an X/19 would it?

Why not work with the weight and the body, rather than throwing vast amounts of money at the engine?

For example,

smoothing the underside with a complete flat bottom
Removing wipers and wing mirrors
rear diffuser / spoiler

How about some more weight saving?

Carbon panels, lightweight wheels etc

I reckon that just sorting the aerodynamics would be good for 10+ mph over 1 mile

Its all very well going for huge bhp, but if the car becomes less pleasant as an everyday drive, then I would have to question the wisdom.

As far as I'm concerned, my engine is pretty much as I want it - positive boost soon after 2,000 rpm. 1 bar by 3,000 rpm. Full boost very soon after 3,500rpm - means I have between 3,500 and 4,000rpm as a powerband.

If I had spent my money differently, I reckon I could have had nearer to 500bhp, but the car would have been very unpleasant to drive.

If you REALLY want monstrous bhp, just buy JohnS's car - 600+ bhp on race fuel - shoud be good for about 180mph / 290km/h after 1 mile

Yes, X1/9.
If I remember right he did have some problems in Estonia (284 km/h), head gasket or something.
His record with the X1/9 is now +300 km/h .
http://www.amworks.com/gallery/video/Fiat_x_19_joensuu_2005_07_17_2.MPG


- Jari -

I thought it was, well there is your answer, get yourself a 16vt.

Yes it was that same X1/9 insane car
I have thought about buying JohnS's car but this means i have to take a loan.. which is not an option. Also i would have to convert it to LHD (we can't register RHD cars here).
At the moment i think i'll try to keep to the spec i wrote up and take some weight off the car. Aerodynamics definately need some attention, thats a good point you got there..
I also thought about sequential turbochargers but i don't think there is enough room for this