non turbo performance!!

[JohnA]

You guys DO realise that it's all in jest, right?

[Bob]

You guys DO realise that it's all in jest, right?

 

 

Do you mind? I'm trying to get into an argument here

[broomie]

Have I ever put you down then mate ?

 

no not you personally fella

[Chris Wilson]

A more reasoned answer for the poor fella:

 

Written by me for someone wanting to tune a 4 cylinder fuel injected Opel engine, but the EXACT same principles apply to all modern multi valve N/A units.

 

Post the early eighties,more and more manufacturers went to electronic

management of ignition and fuel,via fuel injection,and mapped ignition

systems. Most fuel injection systems had one immediate impact. They no

longer need a restrictive venturi (narrow throat) in the carburettor

(s) to pull fuel out of the fuel bowl of the carb. Fuel injection

*injected* the fuel under high or very high pressure. No restriction as

such,and hence less of a power loss. Management of the ignition and

fuel suddenly meant engines could get away with running camshafts with

greater overlap,and higher lift,too. The old advance weight disi,and

velocity sensitive carb limited what cam profile could remain

driveable, without hesitations,poor low end performance and flat

spots. To a large extent electronic management allowed much more

freedom in valve sizes,port shapes,and cam timing,as well as running

the engine at the best amount of ignition advance at all loads and

RPM's without detonation,on differing fuel qualities,via knock sensor

technology.

 

What I am slowly getting at is that it is *much* harder to get

anything like a useful power gain from a modern,well designed,16 valve

production engine on electronic management. The exhausts are free

flowing,as are the intake systems. One needs to look at further

performance optimisation of the cam profiles,and maybe bigger

valves,stronger valve springs,moves away from hydraulic valve lifters

and mechanical improvements to make higher revs safe,from a

mechanical stress related point of view. Almost any change that has the

potential for a marked improvement in power and torque,will require

different fuel curves (the amount of fuel injected at any one set of

parameters of air flow,temperature,engine RPM etcetera,etcetera),and

different timing curves. One can fudge the fuel,*across the whole

curve*,by increasing fuel pressure via an "up rated" fuel pressure

regulator,but the the weeks of dyno testing to get the fuelling

correct at every point,has then gone to pot ... :-(

 

As for the ignition,there is very little indeed you can do to change

the curve incrementally. Unfortunately,the *correct* answer is an

aftermarket injection system,or at least an aftermarket ECU and

wiring,that allows one to map the curves afresh,to suit your new power

modifications. This is expensive,both in terms of hardware,(maybe over

£1000 for the ECU and wiring loom),plus a lot of professional engine

dyno time to get it all mapped correctly.

 

Sometimes one can buy a complete package,say new cams,different

throttle bodies and manifold,etcetera,that can come complete either

with a modified EPROM for the existing ECU,or an aftermarket mappable

ECU complete. If one limits mods to exactly those which the kit

manufacturer intended,this should work well. If you change any

parameter from the tuners package,the early comments about incorrect

curves again apply..

 

Changing the exhaust *system* or the air filter,on 90% of modern

engines will do sod all.The mags claim this and that,but in reality a

gain of 5 HP on a 120 HP engine is neither here nor there,for a road

car. Humidity variations can see that much change. A rolling road is

hard pressed to accurately repeat to 5 BHP on a figure of 120 HP

total. To get greater gains,say 20 HP,you need to look at fairly

dramatic alterations,both to the mechanical components,and their

related fuelling and ignition curves.

 

Turbo engines are a slightly different kettle of fish,as it is trivial

to raise the boost,and usually to fudge some additional fuelling.

 

Naturally aspirated remain tricky!

 

The easiest/cheapest way to see increased performance is to reduce

weight. Especially rotating weight,for improved acceleration. Do most

people ask the most important question when buying new wheels,after

ensuring the offset and sizing is correct? Do they *uggery :-) They

should take a fishermans scales with them,and weigh the damned

things. The first question a race car manufacturer asks his potential

wheel suppliers is what do they weigh,and what is their rotational

inertia. Simple questions,and the weight,if not rotational inertia,is

easily self assessed performance differences can be

surprising,and worthwhile. Given 3 different makes of tyre,with similar

grip and handling characteristics,go for the lightest..Just weigh some

of the cheap imported tyres against a decent performance make,like a

Hoosier competition tyre that is road legal. The difference is

amazing. As for remolds,they are incredibly heavy.

 

If you are serious,and can live without goodies,buy a car with the

minimum spec. Sun roofs,air con,PAS,electric windows and mirrors,power

seats all can add hundreds of pounds. Lightweight front seats can add

as much performance,in real terms,as a new exhaust and manifold. 40

pounds of fancy stereo gear does nothing for performance ;-)

 

As cars become better,and more highly developed,the art of tuning

their engines becomes more complex and expensive,unless one looks at

the situation with a bit of lateral thinking. Instead of adding

things,think in terms of removing them. Instead of buying a new set of

wheels just for their looks,weigh them,and see if a gain can be had

for free there.

 

Just ideas,some may be practical for your situation,some not,but be

aware it is all too easy to buy so called performance bits,and get the

thing to go *slower* At least the engine in your car starts off as

one of the best basis for tuning available.

[ozz]

If someone asks about performance and na supras, then it's only fair to let them know what they could have. Otherwise they may end up regretting it - what if they don't want a reliable daily driver that can be out-accelerated, out-braked, and out-handled my most modern hot hatches?

 

I bought my NA because I was put off by so many comments about the TT breaking down. I'm really happy with her - she doesn't feel that fast but as I think I got 3 points recently thats probably a very good thing! I was also actually put off by people saying just how well they perform as I like to push my cars and I think you could come seriously unstuck with a RWD TT.

 

I get a similar arguement in work from my mate who has a scooby. A 'faster' scooby passed him the other day he's totally gutted and looking to upgrade his turbo. I tried to convince him that he should buy a car for himself, not because its faster than x model. ATEOTD, no matter what you get, someone is going to have something faster so you are always going to dissappoint yourself.

 

My missus lost all interest in fast cars when she bought a motorbike...

 

Out of interest, UK model aside - does the TT have better brakes and suspension than the NA then?

[Max Headroom]

When I had the engine on my NA rebuilt and with an RSR exhaust and 2nd Decat she dyno'd 220bhp. Not bad for a daily driver.

[Max Headroom]

tbh, its all been said. The NA came out of the factory with around 220bhp as standard. Time will whittle this down to around 200bhp. About the only usefull mods you can do to liberate a few more ponies is to fit a full after market exhaust system, remove both cats, and.....erm, thats about it.

 

Mr T's stock air induction system is better than most aftermarket kits - fitting a different one can actually restrict the air flow;)

 

You can throw silly money at an NA but the most you'll get out is another 20 or 30bhp. Better you keep that money and buy a stock TT. You'll be looking at around 320bhp and can BPU it for a grand or so

 

L

 

If you can get your NA engine close to factory stock and by the same token a 13 year old TT would drop from 320bhp to say 300BHP, the difference is only going to be 80bhp. And given the NA delivers its power much more smooothly than a TT, the NA will be 5 miles down the road before the tired old TT has hit boost, or whatever it does when the turbos work. So at the end of the day an NA would get from A to B quicker than a TT. Yaboo hiss to all you TT boys

[squiffy]

Hmm I said the exact same thing when i joined but soon relised theres not much point. Kind of a waste of money when u can go buy the TT and work on that!

 

i agree, i bought an n/a without doing the research. got bored of it and got a tt:)

[Scooter]

 

Out of interest, UK model aside - does the TT have better brakes and suspension than the NA then?

 

 

not really some na's have the 'uk' brakes as do some tt's........and again 'yellow' bilsteins are the best factory dampers and are on some NA's and TT's.........

 

NB uk cars have the softest least sporty suspension of the lot......

[squiffy]

I like to push my cars and I think you could come seriously unstuck with a RWD TT.

 

nah, cant see that happening!

 

 

 

 

[Scooter]

i agree, i bought an n/a without doing the research. got bored of it and got a tt:)

 

me too..............this is the normal progression for NA owners........

 

I would always advocate owning a TT just for the giggles.........my first drive and more memorably the various first times for friends and family where just so funny........truely awesome performance.

 

Doesn't make the NA bad, I still have a hoot in mine its just as capable (better even?) handling wise and is even nice to drive enthusiastically all year round whatever the weather.

[Chris Wilson]

An N/A will outhandle a TT. Based on the fact it's a *LOT* lighter than a TT.

[Gazboy]

I bought my NA because I was put off by so many comments about the TT breaking down.

 

 

I have to ask, what's with all this bollocks about TT's breaking down?

[michael]

An N/A will outhandle a TT. Based on the fact it's a *LOT* lighter than a TT.

 

It doesn't really matter if it reaches the corner 30 seconds later though

[ozz]

I have to ask, what's with all this bollocks about TT's breaking down?

 

I was 'lurking for a while on here before buying my supra. The majority of fault threads seemed to relate to the TTs, very few in comparison for the NAs.

 

Now that maybe because more TT owners mod their cars hence potentially causing more problems, or it could be that they are not as reliable as the NA.

 

I also talked to members of other jap sites who had experience with supras and the theme that came through was that you needed deep pockets to run the TT, similar to the GTO's that I looked at.

 

With so many people talking about reliability there must be something in it - perhaps you are one of the lucky ones!

 

Perhaps someone should do a poll!?

 

I had the same issues when I owned an E36 325, everyone raved about the M3. It looked the same, cost more and unless you drive like you stole it everyday didn't hugely differ?

 

Perversly I would love the TT just for the noise you can get from the turbo and dump valve, but thats the child in me!

[Scooter]

 

Now that maybe because more TT owners mod their cars hence potentially causing more problems, or it could be that they are not as reliable as the NA.

 

 

i think its the modding that does it.......

 

For 10+ yr ols sports/GT cars they are both fantastically reliable IMO. A bpu'd tt is asking a bit more from the turbo's and this will accelerate the wear on them...........also upping the boost with say poor intercooling and spark plug selection and you can risk the engine.

 

As is always stated there is little you can do to a NA engine so they are all well within their normal/designed operating envelope.

They are less sensitive to 'on the dot' servicing and will take a bit of neglect better without causing problems IMO.

[Gazboy]

There's plenty you can do to an NA, but it just requires deep pockets to get any meaninful gains, it's no different to tuning any other NA car, be it an M3, a 911 or a Griffith. You can use a stand alone EMS, bigger injectors, the naughtiest cams you can get your hands on, bigger valves, bigger inlet plenum, gas flowed and ported heads, hike up the compression, use stronger rods and lighter pistons, beefier bearings, tubular manifold & free flowing exhaust, hike up the rev limit to 8500rpm- the list goes on, it's just that you've sunk £20k for another 100bhp.

 

Oh and I'm not lucky, just chooey about where I get my car serviced and don't boost my turbos beyond their caperbilities.

 

Regarding the 325i vs M3 argument- I've never met anyone who has owned an M3 then gone to the same E-series non M version. My bro has owned E36 318iS, 328 sport and now a 3.2 Evo, there is no way he'd trade down, the Evo isn't just a 328 with another 100 horsepower, it's a totaly different experiance altogether.

[JohnA]

I... The majority of fault threads seemed to relate to the TTs, very few in comparison for the NAs.

..

Yes, and in statistics this is called the 'availability error'

Don't fall for it.