RobH 1990 MR2 Turbo Tuning

[robh]

New to MR2's, picked one up from a friend, 1990 rev 1 T-top Turbo.

It already has a CT20B turbo and 2.5" decat downpipe but everything else is stock.

Planning on a dyno run shortly to see what the starting point is.

Then install the following:

KO Racing 2.5" B Pipe
KO Racing Throttle Body Inlet
Link G4 Storm (start with a combination of ST165 base map then tweak with fuel map and cold start settings from ST205)
Larger Gen 3 Injectors
AFM delete
Colder plugs
Gen 3 IAT sensor into Cold Start Injector
Innovate LC-2 wideband

Then run up on dyno for a final tune.

Hopefully nothing goes bang.

[Benckj]

Good to see your tunning plans and supporting mods. Couple of comments worth considering;

1/ IC upgrade. Need to look at this as OEM IC won't keep intake temps down. High temps + raised boost= detonation (blown engine).
2/ Gen 2 fuel supply. Depending on your hp goals will need to upgrade FP and gen 2 rail (and possibly FPR). What fuel do you intend to use?
3/ Boost Control. Take it this will be through the Link?
4/ Other; It isn't all about performance. Don't forget if you make the car go faster you need to be able to stop faster. Brakes, tyres, trans, suspension are all important componentes to mod & maintain.

Not sure if you have read 'Powerprimer' but this tells what to expect from mods.

http://www.mrcontrols.com/primers/power.htm

Pics, how about some pic?

[robh]

Thanks, yes I've done some reading and I'm not really fussed on what I achieve, just having some fun with it:

1. I/C upgrade, I will do something later, aware it will be a limiting factor, but will just wind boost down to a suitable level, plus with the Link can add an inlet temp boost cut
2. No, don't think this will be needed on stock motor, they reckon a rev 1/2 fuel system good for 270ish rwhp, from what I've read injectors are the limit on early cars and I've got the larger 550cc injectors to install
3. Factory boost control via Link G4, I can add a MAC valve later if needed, have read some people reckon the rev 1 solenoid is not as good as the later ones
4. Agreed, brakes are stock but in good condition, tyres are good, suspension has had stiffer inserts added and strut braces F/R, it actually handles well already, don't think it needs to be lower or stiffer

[Benckj]

That's good as its sounds like you have done some research and have a decent plan. The Link will help tune and adapt to mods installed later on. 270whp may be a bit optimistic with fuel rail but will be fun all the same. Just don't be fooled by using AFR's implicitly to tune as center 2 cylinders run hotter & leaner than 1 & 4. Might pay to richen them up a tad to be sure you don't blow a ringland by pushing limits.

[robh]

Understood and agree, in fact I've just ordered an 8mm fuel rail for a friend for his ST165 GT4 for exactly that reason.

[Benckj]

Most people either bore out the gen 2 rail or replace with the top feed type. I mention this as you indicated using the gen 3- 540's which are side mount and will fit gen 2 rail. The gen 3 rail will however, not fit the gen 2 head due to different mounting holes. 'Grrrrrrrr' had a write-up a while back on how to bore the rail out which may be good to read.

This link is from another site on installing new rail which can be helpful.

http://www.mrtwo.net/mr2modproject/mod/ ... system.htm

[JasonFriday13]

3. Factory boost control via Link G4, I can add a MAC valve later if needed, have read some people reckon the rev 1 solenoid is not as good as the later ones

That's not true, the boost solenoid is an on/off type, and it bleeds 3psi off the wastegate pressure (6psi on the gen 3). So you will need a MAC valve to control boost pressure.

Also, the limiting factor on the gen 2 fuel system isn't the injectors, it's the rail. There is a fairly big pressure drop from one end to the other. They fixed this on the gen 3 by boring out a channel around each injector inlet.

The gen 3 rail will however, not fit the gen 2 head due to different mounting holes.

This is partially true, the injector spacing is also different.

On a gen 2 engine you can make around 170/180kw with the stock 430cc injectors and a ct20b turbo. Oh, and 2.5 inch downpipes are better suited to ct26 turbos to help stop boost creep. ct20b's don't have a boost creep problem so they can take a 3 inch downpipe with no problems. I have a Berk downpipe on mine, it's great.

[robh]

Dyno'd this morning, current state:

117kw at 8psi, AFR very very rich.

Depending on when all parts turn up I may or may not bother tracking down why the stock ECU isn't allowing high boost. Already checked for boost leaks, ECU fault codes and that TVSV is ok, might just give up and wait until Link G4 is in so I can more easily see what sensor are saying.

[Alsw20]

Is the t/vsv still electrically connected? A previous owner hasn't pulled the plug under the car?

That is how I disabled the t/vsv on my old SW20s

[JasonFriday13]

117kw would be alright for a ct26, but with a ct20b that figure is a bit low. I figured you've probably done stuff like this in the past, so I won't write another essay about car stuff and how it works.