How much HP does mod X give...

[Rosco_NZ]

Ok thought about a good topic perhaps..

Most simulations like Forza etc you buy a mod and it says it will do X to your horsepower, well how about a list of common/uncommon? mods and typical horsepower increases. obviously it isn't an exact science as some will give more in combination etc

and to be honest i dont have much to contribute to start with.

but how about

Mod / typical horsepower/ recommended combos / warnings..

mod: increase boost by 1PSI/
typical HP: 8hp
RC: induction kits/ air filters / uprated fuel pumps/ exhaust upgrades / intercooler/ hard pipe.
warnings: stock turbos will only blow about 14-16psi even with other RC mods. increased wear etc...


:-):afro:

[bradc]

It's very difficult to really say without a stock car, a box (or two) full of bits and a lot of dyno time :)

[thecustomer]

It's very difficult to really say without a stock car, a box (or two) full of bits and a lot of dyno time :)

... and no two dynos are quite the same /pan

But it's not a bad idea - even if it's just a list of the Club's experience & gut instinct for payback on mods, with health warnings.

ie
98ron fuel +10-15bhp, if you believe Shell & BP's numbers
Performance induction kit ??
Quality exhaust + 30bhp iirc
+ 1 bar boost ??
ECU remap ??
etc

[bradc]

well yeah you would have to have one car on one dyno for a few days :)

I would also suggest that without any mods at all, an exhaust will give about 10-15hp, but if you were to up the boost and do other things first, then change the exhaust, you might see a larger increase.

[thecustomer]

well yeah you would have to have one car on one dyno for a few days :)

I would also suggest that without any mods at all, an exhaust will give about 10-15hp, but if you were to up the boost and do other things first, then change the exhaust, you might see a larger increase.


30bhp, (http://www.clubvr4.com/forum/showpost.php?p=223463&postcount=2) across a fair bit of the rev range... using top quality exhaust though

was this vr4 otherwise standard...

could we settle on +10-30bhp for a twin exhaust?

[Rosco_NZ]

ok maybe we should make the list of mods first...
then discuss our gut instinct. but i like where this is going.
specially seeing as i am getting a new exhaust as we speak :scholar:

[Rosco_NZ]

Sorry Bradc, stolen most of ur mods to start the list, dont know the best way to do this but perhaps just copy paste each time and add to it?
that way the last post will always have the full list...

Mods members have done:
Exhaust , 5-15% or 10-30bhp...
2.5" Downpipes
cat removed
3" exhaust system
2x 4.5" tips

Engine
cams
pistons
rods
Conversion to Manual Transmission
upgraded Heavy Duty clutch

Air...
Air Intake work
Air Filters
vented bonnet

Induction
Pipework
Turbos...
Intercooler (various sizes)
BOV
boost controllers, +8bhp per psi (stock turbos)
bigger turbos
Single Turbo conversion

STOPPING!
disc/calipers
pad upgrades
brake lines

Electrics
ECUs
MAF sensor removal

Misc
Tinted front windows, 35%
Installed DVD player that works with MMCS
CVR4 stickers +10bhp...

Feet..
New mags
Tyres (various sizes and brands)

[bradc]

lol, I wonder how much that dvd player is going to increase power :)

[djb160]

Ive asked this elsewhere but dont we have to have a cat?

[bradc]

nope. the stock system comes with one, but it isn't a legal requirement (yet)

[berg1987]

yet?

[bradc]

I'm sure that crazy bitch in the green party will force it into legislation

[berg1987]

im not gonna lie ay sometimes they just take it too far in ruining our fun ( car enthusiasts that is)

[ako]

My new job is working at a dyno tuning facility in chch, will be doing as much comparison sorta stuff as I can. As much for curiositys sake as my own learning/training on something other than customers' cars!

I've got two of everything, will be testing benifits of modified plenums vs stock, how much power X injectors will make on our cars, how far the stock fuel system actually goes, how much X deflection on an AFC screws things over, so on so forth.

Can't test anything to do with the stock turbo setup - pretty much went with "I know it sucks" so binned it in favour of a single TD05 instead. Why people persevere with it so long is beyond me.

Will also be proving (or disproving) the idea of more power to the wheels from RWD / 4WD, got a 1/4 mile record to retake so will be putting front axles back in after I get sick of opposite lock and leaving big black lines everywhere (or buy another cefiro :p ).

[ako]

Further to the actual topic I guess, can sum it up pretty quickly

Air filters: Useless unless they see cold air, expect around 10hp if they have it. If not expect loud sucky noises, not much more

Boost control: Good idea, you wont make more than 15psi up top and don't bother anyway. Expect a decent gain in power (upwards of 50hp) but crap fuel will kill it

Exhaust: Same as per boost, do it, bigger is better no matter what you read about non-turbo cars. Expect a gain you can feel - around 15-20hp ish.

Computers: S-AFC is a stopgap, anything with full control is ideal, power gains are directly proportional to who is tuning it. Pay peanuts get monkeys, pay big $$ get big hp.

Fuel pump: Will make around 200kW @ wheels on stocker, replace with walbro ASAP, costs $250 and takes half an hour, will flow upwards of 300kW @ wheels. Wont MAKE power, just lets you make more if you can :). The stock injectors on these cars are 390cc's - you'll max out your stock turbo system before you max out 6X390 injectors. Once you NEED to uprate them, you won't be needing a guide like this.

Intercooler: Do it, if power drops off then combine with an AFC to get the actual benefits from it. Most find power drops slightly, these cars run wickedly rich at the best of times and colder air just compounds the problem.

Turbos: Don't expect the world from them. Every other turbo car on the planet gets turbo upgrades, for some reason the TT VR4's just get the stock turbos maxxed out. An upgrade is not hard to do, make new or modify the manifolds you have, adapt oil lines and make new downpipes, there you go. You'll experience a whole new car - one with actual boost control. An AVC-R is half the price of a turbo upgrade and your still left with a 350ish hp power limit. I've managed to do a 400hp capable single turbo swap for around $500 once the stock twins got sold off - food for thought. Don't get me wrong, the stock twins can make around 350 hp all day every day, come on boost like a lightswitch and hardly ever die, but thats as much as you'll get. Trying to make more is flogging a dead horse, all they're doing is frying air above that, no matter how nice your downpipes and intercooler pipes are.

Clutch/gearbox - Clutches, just get one to hold the power your making. No point getting a quad plate 5000lb clutch if you just have exhaust/filter upgrades. Ditto for the other extreme. 5 puck ceramic + 2500lb pressure plate is more than enough at 90% of the power levels these cars see. Gearbox is an evo 4 gearbox with a different bellhousing, all other parts are the same.

Nitrous - great fun, when done right its a wicked mod. Not my cup of tea but hey. Best left to a pro to install and tune, can go wrong very quickly when fiddled with by monkeys, can reap awesome results when done properly.

Internals, custom plenums, etc - once you're at this stage, you are beyond needing a "quick help" guide.

Gauges - Boost = handy. Oil temp/pressure - handy to know your engine has 2 seconds to live. Air/fuel - useless unless its wideband, in which case you may as well just jump on a dyno once a month - cheaper and more reliable :).

Sorry I didn't assign a HP number / combo sort of thing, but at least it gives a basic idea of where its worth spending your money (hopefully). Main thing with any car is have a clear idea of what the goal is and modify accordingly, a 1000hp capable fuel system is all good but a waste of money if your aiming at 400hp - same goes for putting a T51R turbo on a car you're tuning by piggyback computer. A well put together package will have far less issues than one with big $$ in some areas and not others. IE - if you genuinely want a 400hp car, go for the big value for $$ things first, find the bottlenecks.

If I ever get another TT VR4, first thing on the chopping block is the stock turbo setup. I've gone single ex-evo 4 TD05, and have two mates here in NZ going for twin TD04 conversions, one on a 2L 6A12 engine, the other on a 2.5 6A13 (Yes, they both fit both cars with no firewall mods, just slimline radiator fans and thats it). If you have big aims, there is no point in straining a setup at its peak efficency bone stock, same as you wouldn't expect a stock fuel pump to flow the numbers.

[bradc]

I'm still keen to get GT25R's Mark, I've also been looking into these http://www.turboneticsinc.com/turbo_gtk.htm but turbonetics is quite expensive compared to Garrett.

Once I'm up at that stage do you think it is worthwhile to go with twin Walbro's, or something else?