20v turbo Tuning Advice please

Hi Folks, although I have had several Coupes over the years I am just starting to tune my current LE. The engine spec is forged pistons and rods with Garrett 3071 turbo, 3in down pipe and upgraded inter cooler and induction kit, ported inlet manifold with 395cc injectors. I would like your advice on who would be best to remap my car for very usable fast road use with about 330 bhp, am I being realistic? Your advice would be appreciated.

Hi,try FC PERFORMANCE in Castle Combe,he is used to Coupes and is a forum member.

As above try contacting Fc performance. The guy's name is Flea on here.

That's a big turbo for 330 hp.

That's a big understatement!

That turbo is good for well over 400bhp with the right supporting mods

Hi Guys, thanks for the advice.
I am in Shropshire - is there anywhere in the midlands that anyone can recommend for the remap?
Thank you.

Yeah, ME (Voodoo Tuning)! Since I never get a bloody mention on this forum!
I've been tuning Coupe engines for years and have owned (and of course tuned) 20VT AND 16VT Coupes.

And in the spirit of fairness, there's also Johny Bravo Turbo (Midlands Car Servicing) on this forum. TBF, he's a lot closer to where you live, too.

Hi IanLE - Magooagain is right - that’s a monstrous turbo if you’re only aiming for 330bhp. Which turbine housing do you have - 0.64 or 0.86?

Trappy is also right - you’ll struggle to make less than 400bhp, although I suspect the injectors will be the limiting factor - are you also running the uprated 3.8 bar fuel pressure regulator? This will take your 395s to about 500cc

My own car was mapped by Leighton (Flea) and I’ve driven cars mapped by kj16v - both know what they are doing

Just one suggestion - if the true potential of the turbo is realised, you will need better suspension and brakes - 400+ bhp can get you into a lot of trouble very quickly

Great advice chaps - keep it coming!
I'll have a look at the turbine housing tomorrow and get back to you.
If I get a 3.8 regulator will I need another fuel pump? If so, which one?
Yes I've already done the brakes and suspension thanks.
In the ideal world I'm trying to create a very powerful flexible road car not a track car - something that's just as happy at low revs in traffic as it is on the open road.
Great advice so far.

Ian have a look at the top of this section,there Is a a 20 vt tuning advice list,it's old but some info is still relevant.

A coupe tuner/mapper is the best place to get it right.

At your target power, you will definitely need an upgraded fuel pump, as well as the direct feed modification (uses the original fuel pump power feed to activate a relay, which powers the fuel pump direct from the battery)

The fuel pump you need is the Walbro 255lph - there are three models, GSS340, GSS341 and GSS342 - you will need the GSS340

Be VERY careful of fakes - there are lots around - a fake will struggle to supply the fuel and could easily cause engine damage if it runs the engine lean at high boost - definitely buy from a reputable motorsport specialist

A few thoughts...

Uprated clutch goes without saying really...

'Colder' spark plugs - NGK 7s or even 8s most likely.

Straight induction pipe (SIP)- worthwhile if you already have the FMIC.

You said 3" downpipe - you'll want 3" right through at that level.

Good quality dump valve - a few extra PSI over a standard one, even if it still works.

Track day type tyres - it's nice to use some of the power before 70mph!

Short-shift gear change - saves you the walk when changing gear

I'd also recommend a cambelt guard from Flea. Peace of mind in case the belts go...

Great advice chaps - thank you.
The turbine housing is .86 by the way - what benefit is this?
With regards to the clutch I was thinking of a DriveTorque stage 2 as i think it may be better in traffic but still be able to handle the extra power when needed - what do you think?
I presume the upgraded fuel pump is a direct replacement of the original?
I'll order a let guard from Flea.

AR 0.86 on a GT3071 is big for your power goal, you won't have full boost before 4500rpm and then it will go a bit crazy -> you should go down to something around 0.64 which is already good for 500hp+

A gt3071 is not a "good streetable 330hp turbo", you should sell it and take a gt28rs or gtx2860r, those are good turbo for 350hp goals (at least)

I wouldn't touch DriveTorque. DriveTorque is one of the many names for CG Motorsport. I used to use their clutches - until they started palming off poorly built products on me and I had to take them to court. CG Motorsport and their shonky clutches were the exact reason why I developed my own uprated clutches Coupes!

A GT3071 0.86AR is good for over 500bhp with supporting mods

It will be far more laggy than you need - a turbo capable of delivering 350-ish bhp should be spooling before 3,000rpm - with the 0.86AR turbine housing, a GT3071 won't spool fully until over 4,000rpm, which will leave you a pretty narrow powerband.

I would echo Julien's thoughts above - sell the 3071 and get something with a significantly earlier spool (unless of course, you expect to carry on modding... )

thanks for your advice - how much is one of your clutches? i'm trying to avoid a paddle clutch as i've heard they need a few revs to pull away and are difficult in traffic.

Just for your Reference and comparison!

I have 358 bhp 311lbft torque
only major changes are
GT28RS turbo .64
H&S downpipe
Pro alloy FMIC Short route mod
Pro alloy SIP
Boost controller
Cone filter
Direct feed fuel pump wiring
Helix uprated clutch

Flea did the live mapping, the car is very nice off boost and is also very fast but very linear, there is no sudden kick, just very smooth and progressive power, the clutch was slipping when set up so settings were tame on the boost controller due to this (i think)
I have never adjusted the settings since, as this is a standard engine Non Forged
I know i could turn it up and bring the boost on stronger but its fine as it is (for me anyway) perhaps one day when i have more time

£550 + postage

I have double checked my turbine manifold and the casting has 64 on it- am i looking in the correct place to establish if its a .64 or a .86 size? if not where do i look to find out? I've got the turbo off now.
if i have a .64 at what revs will it spool up?
thanks
Ian

There are lots of other factors that could affect spool up, but a 3071 with a 0.64ar turbine housing would probably spool at about 3,500rpm. 0.86 about 500rpm later

I can vouch for Voodoo/KJ's mapping and clutches which if feel is important drive no different to standard.