s9ott

Needing help on what Turbo would be best in my 2wd 3dr cossie, i would like good 1/4 mile times and a fast track car, so want best of both worlds, big turbo with low lag 600 ish bhp.
Also wanting to go external waste gate, so thinking GT35 or GT40 but what housing etc etc ?????
Would get air and water injection too if it will help with setup.

car spec as below
Bottom end
Block been bored out
All parts lighten and balanced
New ARP con rod bolts
Forged pistons with pockets
Piston rings gapped for running nitrous if I want later
New light weight and balanced fly wheel to accommodate smaller diameter clutch
Twin plate 6" paddle super clutch
High pressure oil pump with new shaft
Baffled sump
Competition engine mounts
ARP Fly wheel bolts
Head
Compression ratio at 7.9 to 1
Polished and ported head
Both inlet and exhaust manifolds’ matched to head and polished
inlet manifold spacer
New standard valves, guides, seals and hydraulic lifters
Double valve springs
Multi layer WRC head gasket
ARP stud and nut head kit
ARP stud and nut kit for exhaust manifold
Variable cam pulleys
BD14 cams
Turbo dampener
T34 stage 2 turbo from GGR
-31 actuator
Other bits
Turbo cooler
3 bar map sensor
Siemens Deka 83's FI11405 (old P/N 3105)
RS500 style intercooler
Group A dump Valve
K&N cone filter
Group A oil breath system
Alloy water tank and swirl pot
Full air and water Samco hoses
AVO coil over suspension
Poly bushes all round
Poly Exhaust bushes
Front & Rear strut brace
330mm front breaks and full set of braded hose
L8 ECU
Evolution chip
launch control
anti lag
closed loop
coil pack convertor
Full 3” s/steel exhausts system
GP A fuel pump
Hydraulic clutch conversion
bonnet spacers

black_jack

Lets not all answer at once guys!

1st of all i have no idea which is the best turbo/ housing etc even if such a thing did exist - what would be ideal for ultimate power would not be ideal for lag etc and one drivers acceptable amount of lag is anothers acceptable lag there is no "right" way or "wrong" way - so its a balance/ compromise between ultimate power and lag

you may have to change parts/ setup to get the best results for drag or track or road or settle for some sort of compomise

here is some ideas / comments -

if you heatwrap or ceramic coat your exhaust manifold it will get more heat into the turbine - reducing lag

turbos don't need a tuned length exhaust - the shorter and fatter the exhaust downstream of the turbine, better/ the less lag - a side exit 3 or 4" (single) side exit exhaust with straight-through muffler will reguce lag/ may increase top end power

the GT series is more efficient than the T series and you may be able to go smaller than expected (thus reducing lag) and still produce the required gas-flow / top/ end power.

A modern electronic digital boost controller will outperform a mechanical actuator/ older controller - it can reduce lag and can have much more precise control over peak boost pressure as well as making a big difference to the midrange power/ torque

I always feel the traditional intercooler is a bit big and inefficient a smaller one with a lower internal volume may produce similar top end power but with less lag - especially if you ran a water spray (external to the intercooler) - an air/ water chargecooler may be the way to go - hoses would be shorter, the core would have an even smaller internal volume and you could have an ice tank for drag racing

i don't rate k&n's even if they have a heatshield and cool air feeds - you're far better off with a fully encapsulated CAIS - Venom, BMC etc

i like the spec of your car!- did you do/ choose the mods? what type of anti-lag and launch control do you run?

s9ott

Black jack
Thanks for your good feedback.
I’ve picked and done all the mods myself and just learning as I go, car was standard apart from the last owner put on coilovers and the wheels that were only held on with 2 threads from the standard wheel studs, lucky for me it was a non runner when I picked it up with the electrics fried in the engine bay.
The Evolution chip is from MSD with the Anti Lag, Launch Control, closed loop & coil pack convertor, once I get the new turbo on I’m going to get it live mapped at MSD.
Had to google the ceramic coating but it’s now on the list to be done, is it worth doing the new Turbo as well?
The k&N will be changed with the new Turbo also.
So I guess I need to find the smallest Turbo that can put out the 600 – 650bhp I’m hoping for, anyone any ideas of what a GT30 or GT35 can put out and what setup?
Cheers
Scott

black_jack

Nice one! - you can ceramic coat the turbine housing and the external wastegate (everything between the exhaust ports/ turbine - to get heat into turbo/ reduce lag) or you could go one step further and do all the hot parts of the exhaust (eg downpipe) to reduce heatsoak (with heat wrap to increase effect/ reduce cost) esp. when waiting on the line before a race

with a vented bonnet (spacers at the back) it can massively reduce underbonnet temps
from what ive read online and what others have done looks like you might have to go for the gt35 to get 600+ hp, as the gt30 would be a bit less (about 500) -or even getting a hybrid specially built - no idea what would be the best for lag and its not my area of expertese and you may be better getting expert advice - MSD?

if you are running an external wastegate you could fit a screamer pipe (noisy, not road legal/ may allow exaust fumes into cabin) but have it silenced (little straight-through silencer!) with its own exhaust, seperate from the main one (thats got to be worth a few Hp) - if it went out the side or back and was quiet enough it could pass an MOT?

I could not find any detailed info on the launch control - is it switchable?/ adjustable?

s9ott

The MSD Launch control for the L8 ECU is set at just under 4k, works well in my car but dose give me traction problems with my rear tires only being 235, changing the wheels so i can go wider with Toyo R888 all round.
http://www.motorsport-developments.co.uk/launchcontrol.html
The external wastegate will have its own pipe, going to try and make a quick release fitting so i can have the option of a quiet or fun pipe.
When looking at the GT35 on line there is so many different types

Ported Shroud (Anti-surge) (Yes please)
Polished Housing (Yes please)
Turbine Housing A/R: (Feck knows)
Exhaust housing size (Feck knows)
Turbine inlet flange (is it a T3 on the 2wd sierra manifold)
Exhaust Flange (what is the standard Cosworth 3 stud flange called)
Wastegate size (Feck Knows)
Ball bearing, journal bearing, dual bearing, R type.

So many options, like you say I will have to talk to maybe MSD as they will be live mapping it, and the turbo company that make them.
This will be the 3rd turbo on the car so want the best of everything as don't want to change it again.

I will add the bonnet spacers to the list too, just as well I’m working every day till the end of the year lol.

opposite lock

iTrader: (3)

A 600+ 200 block YBB is gonna need some serious attention to every detail. A serious tuner would probably prefer to go right back to basics checking your engine is capable of the power ect its more than just speccing a GT40 and and turning the key as im sure your aware.
Lots of development has gone into this stage with various tuners , different turbo,s and ECU,s are just a starter.

Fezman1

iTrader: (1)

From what i can read, im not sure if your bottom end will cope with 600-650bhp...or at least not reliably.
200block? has it been linered/long studded?
How much port work has been done to the head?

In terms of turbos... garret gt/gtx, borg warner, turbonetics, holset all do turbos they may suit your desired power level.
And i notice in your last post you are talking ported shroud on your turbo?- if you want least lag- dont go ported shroud.

s9ott

thanks for the info, ported shround binned saves me cash too.

The Head porting was done with the 600BHP in mind, as for the block i'm willing to try it with the APR nut and stud kit in now.

s9ott

I'm starting to think i should go with a GT35 setup and get as close to the 600BHP i was wanting.
I can change the block the next time it blows up

Anyone running a GT35 with good results?????

opposite lock

iTrader: (3)

Its gonna come down to either your budget or how far do you want to go scenario.There are quite a few peeps on here familiar with your choices of turbos and power levels. There are other turbos i.e Borg Warner that are getting good results but its a ground up conversion imo. Everything has to be spot on or it,ll be unreliable .

s9ott

I'm willing to change inlet manifold, cams, add water & Air injection etc later if needed, but to lazy to pull the engine back out and open it up again.
Just want to buy a turbo that is good up to 600bhp, and see what my set up will do with it, then from there I can change other bits to build up to that kind of power if possible, don't want to spend $$$ on a new turbo with external waste gate to have to change it again later.

I’ve half made up my mind on a GT35 Turbo, as I think the GT40 will have to much lag for me, but as to the spec of the GT35 I’m needing advice on

opposite lock

iTrader: (3)

If you,ve chosen a tuning company like Motorsport Developments to map your setup then its best to get in contact with them . Lots of variations in setups and the engine may or may well not be suited for it .
Who built the engine?

s9ott

Contacting MSD is probably my best option see what they think.
The engineering work was done by Agra engineering in Scotland, but I built the engine and timed it all up myself, engine and turbo have been good for road use, but want more power now for 1/4mile and track days.