How much can a standard 20VT stand? Without changing the engine parts...

Regards, Radicz.

depends on how it`s done,if you get better intake air cooling.......ie front mount intercooler,Aquamist,charcooler,and a decent exhaust,i`d reckon 280-300bhp,a good bit less if you don`t take care of cooling first tho`

If without changing the engine parts you mean no strengthening i.e. forged pistons, rods etc then you are looking at anything from 350bhp to perhaps close on 400bhp. This assumes you have perfect fueling (across all cylinders), very low charge and cylinder temps and boost pressure is probably no more than 1.5 bar.

The reality is there is not exact limit as each car is different and you are only as strong as the weakest link.

350bhp -400bhp on standard internals...yikes your a braver man than me .
I reckon thats ok if your Barbz or Rog. i.e. full time coupe mechanics/specialists,who have the knowledge/ experience/tools to wip out a broken part every now and again,i wouldn`t risk running that kind of power and not expect a major breakage before too long

I can understand your concerns but I think we still don't know enough about the 20vt engine strength because very few have gone past 300bhp let alone 330-400bhp. However for those that have gone beyond it they have done so reliably for quite a long period. Jari (350bhp)and Stichl (390bhp) have been running this power for around 18 months. Dan and DrFrag have been running 320-340bhp for about the same period and I have been running 360bhp daily for the last 7 months. Obviously going for forged internals will introduce a much safer margin early on but even this won't stop you breaking the engine if the setup isn't just right. I think the most important aspect for me, regardless of what power I am running, is to ensure that the engine is mapped and cooled correctly.

I was led to believe that with proper coolling and fuelling, 300 bhp using a 28R or "above" is not pushing things too far at all. There's quite a lot of members running this power and more, no ?

having 400, 300, 500 etc bhp is always gonna be a misunderstood power rating, as YO UWILL NEVER be drving the coop with it at the limiter all the time, thus, the engine life depends upon how you drive it really..

i used to drive at 1.4 - 1.5 bar on a standard turbo...no probs, but then it was hardl ever at 1.4 all the time...

still going fine 65K later....

erm.....that is till I take it apart purposely for an upgrade

I'd say as above somewhere between 350-400bhp provided the engines mapped and cooled properly.

Its very difficult to say exactly, as there's not many Coupes running these sort of figures with standard internals. There have been some discussions in the past about the strength of the standard rods, when you are pushing high torque levels, but as to whether the failures were isolated problems or just indicative of a mechanical threshold being reached yet, I'm not so sure.

I've been running at least 340 bhp for some time now, I've been lazy getting a rolling road and a proper remap, so I'm not sure, but I'd expect somewhat up on that. The only problem I've noticed is that when pushing high torque levels 3500-4000rpm, the GTA clutch can start to slip , and frankly I've found in the winter I just end up with wheelspin!

regards

Joe

Taz, that is very very true. I must say I don't hoon around like some of the other youngsters on the forum e.g. Hanny and Nigel I push the car flat out near enough every day but this is for short bursts not sustained redlining at max boost. That said, I won't have a problem with doing 3-4 hot laps on the track at 1.4 bar... the engine might though

Again, surely the engine is man enough to cope with 3-4 laps of caning

If not I'd say it's running pretty much to it's limit That's like, what, 20 minutes or so to kill it ? Or am I taking it too literally ?

I ran stock rods to begin with on my 2.4, and at 408BHP and 400lbs/ft. After 15000 miles four rods were bent and the fifth had snapped.
I only used the stock ones due to the leadtime on the forged rods but I think it shows that the limit is below a genuine 400BHP and 400lbs/ft. Of course in pub talk BHP they'll probably take 550BHP

On my old 2 litre engine I ran 340BHP and 320lbs/ft for 25-30,000 miles/ 1.5years on std internals. But that was at only 1.1 bar boost... All the rods were ok but I melted a piston when experimenting with 1.7 bar boost for 3 months (giving around 360BHP) I was well over the safe duty limit for the injectors with a 3.8 bar reg

John

So down to brass tacks then - by the end of the month, my 20VT will have a 28R, Pro Alloy FMIC, TI straight induction and RamAir, Profec B II boost controller, some sort of uprated downpipe, Walbro 255 and GTEC 2, and will then be mapped to make sure the fuelling is OK (I'm assuming the cooling will be fine with the FMIC).

What sort of bhp can I expect, what boost level should I run and how long will it last ? Don't forget it has to be safe in 50 degree C ambient temps as well Do I just keep upping the boost to the extent of the fuelling capability ?

For the sake of a nice round number, I'm hoping for 300 bhp - is that too optimistic ?

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1.2 - 1.3 bar will see you get 300 I would think, but also will give high temps for you I would have thought. A lower bar would be safer due to your surrounding temps, but the profec has 2 settings doesn't it, so you could have 1.2 / 1.3 for those short quick bursts and then 1.0 / 1.1 for day to day driving. 1.1 would be around 260 / 270 I would have thought

That all sounds exactly what I was after JimO and hopefully won't need rebuilds every 1,000 miles

only my opinion though, my car will be a similar spec to yours in a few weeks, and they are the sort of figires I am hoping to run with, but I will probably only push mine to 1.2 bar

interesting opinions............and by folk more knowledgeable than me............all have more faith in fiat OE components than I do

Having had one of the more dramatic blow-ups on this forum...a genuine 413bhp and 390 lb ft, standard rods survived about 10 miles running up and down the straight at Millbrook and 3.5 laps of Goodwood

Don't recommend running that kind of power of stock internals. As Johns says, I also had everything else set up to run this kind of power safely - giant FMIC, 903cc injectors, proper mapping on Motec etc etc

Its a false economy to run big power without building for it. Maybe the 20vt will put out 300bhp all day safely, wouldn't want to run much more than that without the right internals as the cost is too much when it all goes bang

What about injectors ? How much can a standard 20VT injectors stand ?

jayell and JimO , these are the sort of mods I am hoping to undertake by summertime. My question is what sort of cost are we taking about.. just looking at a bold park figure??

Seems like 300bhp is a good safe figure, however what kind of torque figures are we expecting

Great thread

Nazo

very roughly, not incl fitting

FMIC - £400
Turbo - £600
Unichip - £400
Boost Controller - £200
Fuel Pump - £100
Cone Filter - £100

Fitting, who knows, depends where you take it all and if you do it all at once, but I guess another £300 to £400 maybe.

Outright power will depend on the turbo and the level of your boost. I don't think I will hit 300 @ 1.2 bar on the superspool, but should be close. But to me its more the driveability with the turbo kicking in nice and low hopefully. Torque I guess around 270/280.

A good graph to look at is JamesH's in tuning as he is running the same mods pretty much to jayell and me.

HTH

Well on the basis that the following parts should give 300bhp, I've paid or will pay the following (parts costs only - labour charge is at the end):

GT28R turbo : 600 quid
Pro Alloy Front mount intercooler : 400 quid (no VAT for my order)
Straight induction mod and Ramair filter : 170 quid
PRV : 22 quid (or boost controller - say 200 quid for a Profec)
GTEC 2 chip : 46 quid
Walbro 255 uprated fuel pump : 90 quid
Uprated downpipe (prob.2.75") : 150 quid
Uprated dump valve (standard plastic one will probably leak boost) : 80 quid
Boost gauge, if you haven't already got one : 50 quid.


Add say 20 hours labour for fitting that little lot, and you're going to be looking at 2k+ or so. Torque-wise, I'd hope for a similar figure in lb-ft to bhp, but that may just be wishful thinking. Also don't forget that if the fuelling is not spot-on from the GTEC chip, a Unichip will be necessary at 450 quid or so.

If anyone wants to add to or contradict any of the above, feel free as I wouldn't mind the advice myself.

edit - JimO - sounds like we're thinking on the same lines here

edit edit - JimO and JamesH are running Superspools, I'll be running a GT28R - should give a little more power, and be tougher.

quite close to each others figures, totally agree with them.

Exhaust, 3" decat system £400

Also, I would say at this level you should definitely have a boost controller and not a prv. But as jayell says I just got a profec ii for £202

funnily enough it was your advice saying that 1.2 bar would be enough that's making me consider sticking with the PRV for the time being Might get a Profec a bit later on, chucking money after the Fiat is losing it's appeal at the moment

Thinking about it, what I gain with the 28R I'll probably lose by not having a Unichip, so we should be about the same

Please keep in mind…
It is the torque, which will destroy the engine – not the revs…
The 2l- 20VT engine (on contrary is a 16VT) is a short stroke engine capable of doing a lot of revs… (limiting problem are the hydros… for sure)

Following example:
Let’s make following assumption:
- 20VT with GT28RS, with 1,8bar at 4000rpm, maximum power about 360HP with maximum torque of 520NM at about 4000rpm.
- Second:20VT with GT2871R: 1,5bar at 4500rpm, still 1,6bar at 6500rpm, about 400HP with a maximum torque of 460NM at 4500rpm

What do you think – which engine will fail first?! It’s the GT28RS- engine…for sure!!!
Interesting would be to know, what maximum torque the rods can take without leaving the elastic area and changing to the plastic deformation (bending).
I for myself think that the original non-hazardous rods can take about 400 – 450NM for a longer time.
Additional shot-peening and lightening of the rods (like mine) will achieve additional 20, 30NM…
I am driving a coupe 20VT with 397HP (now for 7000km) and a maximum torque of about 500NM… a little bit too much for a good durability, I think…
Juergen

rember the base engine also had an influence, consider the milage and perhaps previous usage. Continued high revs is what will kill an engine or rather its the fatigue on the rods, but any engine having done 100k may not be the best starting point for a high power unit. Not saying OE rods are all bad, but old ones are probably asking for trouble.

rich

Nyssa + Paul - you can include me in this as well. If you push your car anywhere near a perceived limit then you need to be prepared and have a few grand in the bank for a rebuild....

I agree, having an engine 'go' on you will change your preconceptions somewhat, however, I would like to throw is some more fuel to the 'fire'

Of the engine failures that occur on the Coupe, they fall into either piston or rod failures.
Almost all the engine failures are piston failures.
I'm not including turbo faliures as this is obviously something different.

Now if you look statistically at the piston failures, I'm sure Rog and Barbz would agree, they tend to occur in standard or 'lightly tuned' coupes, those running plug and play chips and standard turbos and intercoolers , although statistics can be misleading as most of the Coupes may well fall into this category by numbers alone.
So whether this is due to incorrrect engine mapping, or excessive charge temperatures, or a combination I don't know.

However look at the number of higher powered coupes running proeprly mapped cars roller bearing turbos etc, and you can see that quite a number are running 300bhp+ for some considerable time now.

Of course there must be a mechanical threshold, even with cars running water injection etc, but where this is??, I mean how many failures at 350bhp+ have there been?, I mean seriously, how many?, hardly any in truth, but then the number of cars running 350bhp+ are scant and few, so its hard to make definitive information.

Ones I can think of, is Fergies car on the rollers, being put down to mapping and very high overboost, then there's Barbz 'experiments' with NOS and again very high boost levels, JohnS, and err can't think of anyone else.

Still, having a piston go, is very unfortuante and expensive, and running less power should surely increase reliability, but maybe not as much as you think

With the rod failures, there's Nyssa and JohnS, both showing failures along the 400bhp mark, but with two cars again it gives an idea only, but again likely to be somewhere less than this.

Joe