Mk2 Na Tuning Questions.

[Phil Hall]

Hi folks,

Im just basically wanting to know how much bhp I could expect with sensible mods on a 2.0 GTTbar (1992 UK model).

Insurance in NI wont let me get either an Import or a 3SGTE beast, so without going the forced induction or TB route what mods can I make to see bhp / torque gains?

Ive heard that there is no real benefit to be seen from gas - flowing the head as the OEM head design is more than capable. Is this true?

What is the OEM exhaust system like? ie is it very restrictive?

Do these engines respond well to a set of aftermarket cams?

Do these engines respond well to re-mapping / chipping?

What can people recommend for the sweet 16? and does anyone have any proven figures / RR printouts with mods mentioned above?

Cheers in advance ppl...

Phil

[Rookey]

Hi folks,

Im just basically wanting to know how much bhp I could expect with sensible mods on a 2.0 GTTbar (1992 UK model).

Insurance in NI wont let me get either an Import or a 3SGTE beast, so without going the forced induction or TB route what mods can I make to see bhp / torque gains?

Ive heard that there is no real benefit to be seen from gas - flowing the head as the OEM head design is more than capable. Is this true?

What is the OEM exhaust system like? ie is it very restrictive?

Do these engines respond well to a set of aftermarket cams?

Do these engines respond well to re-mapping / chipping?

What can people recommend for the sweet 16? and does anyone have any proven figures / RR printouts with mods mentioned above?

Cheers in advance ppl...

Phil

Aye, t'would be good to hear this aswell :)

Try and include some mopds for the 3S-FE engine people! :P

Dave!

(Sorry for hi-jacking the thread slightly, just thought its better than starting a whole new one!:P )

[Phil Hall]

No worries... welcome to my thread.... All we need now are some friendly people to enlighten us.

[TheNissanMan]

basics make a big difference to the NA, ecxhausts like Mongoose are superb and reasonably priced, Apexi induction kits are great...

bhp increases as expected on an NA aren't excellent but the repsonsiveness and torwu increase is worth it...

Something like a Unichip is defo worth it as well....

Suspension would also be a good place to start :)

[Bibbs]

Get more air in .. and get it out easier ..

So the basics are exhaust & filter .. cams etc will move the torque up the rev range so more BHP.

Then add a chip to fine tune the fueling ..

[Titto]

I've been reliably informed that gasflowing does make a considerable difference to the engine revving more easily! This is on my wish list!

[EarL]

Basics, basics, basics!

Start with the induction and exhaust dude. Like Bibbs said, the more you can get in, and the easier it is for it to escape, the more power you'll make.

Things like cams and stuff will come later and cost a lot more because it's strip down time. That also goes for porting and gas flowing the head. You're not going to see a great deal of difference from porting the head and having bigger valves without a cam swap, and that means one thing...

C.A.$.H. :o

It should'n cost yu the earth to improve your basic setup and get a good healthy 25 - 35 bhp outta the motor by doing the basics. Try these to start:

1. New Plugs - lower heat range (NGK, HKS)

2. New Dizzy - Copper contact type

3. New rotor - Dizzy's 'n' rotor's should go in pairs

4. Decent leads - Try Magnecor

5. Oil!!! - Mobil 1 or some other good full synthetic

6. Induction Kit - Blitz, K&N, GReddy etc, etc

7. Exhust headers - decent mandrel bent type - millions to choose from

8. Decat pipe or gut the cat - 10bhp alone here!!!

9. Good exhaust - millions of them - not too big, need to keep some backpressure

10. Rolling road time - set it up properly.

The above is just a guide, but I think the rest of the guys who know anything about tuning will agree with me there. The small things are the things that count.

Have fun.

[Jimlad]

sell it and get a Turbo.... :D

[Rookey]

sell it and get a Turbo.... :D

I was waiting for that! :D

[midmotorsteve]

1. decat

2. induction with COLD AIR

3. cams and timing, BUT can't go more than 264 duration as shims will get thrown, as shims live on top of the lifters, so to go to 272 etc you need a shim under bucket conversion, had mine done for £220 but never got it fitted as my block was cracked so thought f it and had a turbo conversion :D

then the stage would have been dastek unichip that should have seen 200bhp + maybe 210 bhp

[EarL]

sell it and get a Turbo.... :D

There's always one... :D

[Phil Hall]

What is the STD bhp / torque figs for a 2.0 GT N/A UK car?

[EarL]

Think they range from around 150 for a rev 1 to 175 for a rev 3.

[JohnnyC]

What is the STD bhp / torque figs for a 2.0 GT N/A UK car?

UK:

BHP:

rev1 = 158

rev2 = 154 (due to cat)

rev3 = 173

rev4 = 168 (more emissions stuff bringing it down)

rev5 = 168

0 - 60mph:

revs 1 & 2 = 7.2 seconds,

revs 3 - 5 = 7.7 seconds.

Torque:

rev3+ = 137lbft @ 4800rpm

[dawolf]

I thought one version only had 119bhp or was that the mk1?

I'd be interested to know what mine is kicking out, it's a rev2 (154bhp) with cat-back exhaust and panel filter. I fancy getting a de-cat soon!

[Bibbs]

the 119 was the Coupe or the G ..

it had the 3S-FE engine (economy head) and is the same engine in the Carina and Rev4 (as well as many others)

[dawolf]

What about the G-Limited imports, they have 154bhp right?

[Bibbs]

G-Limited? Yeah .. same as the UK spec ..

only the G and Coupe were the econ ones ..

[Spartan]

As already put forward maintainance is the first step towards performance.

If the engine and its sub systems are in good nick then first thing to sort is breathing.

I'm not partial to induction kits or open air conical filters of any kind. I've tried many and have found them to all cause the same problems. The dreaded heat soak. As the engine bay is quite tight on the MR2 I would stick to the standard air box with a quality filter, such as K&N or Apexi if available. Filters like HKS foam and Blitz metal mesh are crap. Pipercross are also crap full stop. Ramair, K&N, Apexi are probably the best out there, although I've heard green and TRD are good. The TRD filter is quite expensive.

You can then mod the airbox for better flow, if possible enlarge the cold air intake and make a nice lip and place a larger hose on it.

Alternatively, if you prefer induction roar over absolute performance then fit an induction kit and make a custom enclosure for it to protect it from heat.

Exhaust wise, back pressure is your friend in N/A engines (to an extent). Back pressure means greater scavenging, which leads to better efficiency and hence more power. So basically you don't want to make you exhaust's ID larger than 2.5". As said dump the CAT, or fit a high flow one if you want to remain hassle free and legal. With terms of exhaust manifolds if I remember correctly a short, equal length manifold (4 into 1) will provide better peak power whereas, a long, equal lenght manifold (4 into 2 into 1 or equivalent) gives better all round power with no major dips or peaks in power, ie a smooth delivery.

You can port and polish yourself it is quite easily done, but does need time and some mechanical knowledge as well as a hefty dose of common sense. You can also optimise the TB and maybe even enlarge if feeling adventurous.

The above may give quite small power gains but better running. A uni chip would be an excellant addition. You might also be able to play with the timing to tweak a few more BHP out of the engine.

Playing with cams, shim conversions is a very expensive way of tuning. Neccesary if you want absolute power. If you do go this way, it will mean very little torque and lots of high revving action which I would reccomend an upgraded oil cooler, and maybe even a swirl pot for your coolant system.

Or you could just save alot of money, fit a cat back exhaust, and a filter then fit a wet nitrous kit for around £500. With a well maintained engine you be able to fit 75BHP jets and maybe more with a progressive controller.

Then you have the power when you need it, still retain everyday drivabilty and reliability plus you will be able to replay the nitrous RX7 scene from fast and the furious when you push the button and wave yer willy while doing it!*

*willy waving optional.

Changed the decriptions of the manifolds, had em the wrong way around!

[Rookey]

I thought one version only had 119bhp or was that the mk1?

I'd be interested to know what mine is kicking out, it's a rev2 (154bhp) with cat-back exhaust and panel filter. I fancy getting a de-cat soon!

Mine!:P

Dave!

[EarL]

You can port and polish yourself it is quite easily done

WHAT???

Easy to port and polish? Yeah right! :censor:

To start off with...

Polishing the chambers is not recommended as it leads to fuel pooling and consequently poor fuel consumption and rough running. A rough surface is preffered as it promotes better atomisation of the air/fuel mixture.

Get real mate. If it were so easy to port and polish, every !Removed! head would be advertising their services. It's a VERY specialised process that involves many years of practice by an expert.

PLEASE DON'T BE TEMPTED TO TRY AND PORT YOUR CYLINDER HEAD YOURSELF!!!

If you're going to offer advice to someone who is obviously a beginner, try getting your facts right first. :ffs:

EarL.

[Phil Hall]

LOL True!! Port polishing is not for beginners. Ive re-seated the valves on an old Popular Plus Fiesta using the old paste and plunger but there were 2 spare heads lying around incase I made a mistake. There's no way I'd try porting my 2 when I buy it.

With regards to the polishing, Ive heard that the burrs inside the cylinder head actually help the mixing of the air/fuel and people are often dissapointed with the results after PP.

I'll update the points, plugs and leads, dizzy and sort out the breathing and then take it from there.

All I have to do now is find a GT-Tbar within 60miles of Liverpool Airport for less then 3k. - MISSION!!!

[EarL]

Best of luck Phil. I'm sure you'll find a good 'un!

[Spartan]

*double post*

[Spartan]

:P Sorry I should have posted a bit more on port/polishing but it was getting late and I was getting tired.

Remember just because someone is new to the boards, and is asking basic tuning questions relating to a specific car it doesn't make them a beginer to cars and engines in general.

Right, anyway. What I meant by port and polish was some very basic work that is in actual fact easily done. I am not talking about multi angle valve jobs or any of the serious work.

Jobs that are worth doing are:

Port matching, ie matching the intake side manifold to head for best flow properties.

Exhaust port polishing to prevent carbon build up.

Chamber polishing to prevent carbon build up and remove sharp edges that can cause pre ignition (ie detonation). Leaving burrs or flash does not help prevent pre ignition. Not that I've heard anyway.

And last but not least a little fettleing to the sort side radi (i'll post some links that will explain a bit more).

You are quite right about fuel pooling, polishing anything on the intake side to a near mirror finish is wrong and screws up things.

I think you will find most jobs in the automotive world are listed as "VERY specialised process that involves many years of practice by an expert." this is how they make their money. As I pointed out I'm not talking about a race spec job which does require years of experience and specialised equipement (such as a flow bench), but a basic port and polish.

Two things I really hate about car forums, people who speak crap and people who jump the gun and then try and call people stupid.

As pointed out, it needs some mechanical knowledge (enough to break down the head and reassemble it), alot of common sense ans research. A steady hand and a die grinder (which means a compressor as well) and a port grinding kit you can pick up from demon tweeks or other places. It takes alot of time, but can be rewarding if done right. You should also go to the scrappy and grab a couple of spare heads (old Nova heads or fiesta) and practice on them.

I still stand by the basic breathing mods and the nitrous though!

:P

Also good luck finding a good example, best advice there is to take your time! :)

This site helped me alot in the past.