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i have a big FMIC, 700hp fuel pump, GTR injectors, custom piping, custom exhaust with split dumps off each turbo, running into a 3" system, through a 3" hi flow cat, adjustable fuel pressure reg, microtech LT8 with handset.

i think he said boost, if i wanted 200rwkw he said u'd need much more boost *shrugs*, lol. At the moment i can't really afford another re-tune so im stuck.

sif big FMIC! Mines bigger!

I can say that Jao's car is a bit of a lag beast (from what ive seen) and traction sounded like it was an issue when he fanged it up the hill, but its cool and im shitty that he has a RB20DETT and i dont! :P

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my gtr greddy manifold was modified in japan to fit an rb20 by simply welding, machining and drilling extra tangs onto the flange. the ports still line up perfectly.

ie instead of \ \ \ / / \ its now \ \ \ X X \ (yea dodgy explanation but i'm sure you get it) :D

lol, sproosy, posting again i see :)

Yea i'd love to get some help to extract every single extra kw out of this thing, as it seems to be, well, under powered, any help/ideas/places to go for help? roy? :)

LOL...I dont know. :D

I am curious to know what turbos it has...can you see any markings on the housings?

on mine? Standard 32 GT-R turbos i think, suppose i could take a sticky beak if you want.

Any suggestions on what to do next to get best gains and smooth out the power curve?

Well, call me simple minded, but R32 GTR turbos have been good for 220-230rwkws at 1 bar on plenty of GTRs...i wonder why they wont make similar power on an RB20....(note i said similar power, not the same power)??????????

Microtech LT8, they can be tuned via laptop cant they? Got a copy of your tune, what sort of ignition and fuelling does the engine have. Also have you got air temp compensation wired up and tuned for?

Id say dump the cat, and have a look at the tune. My R31 GTS-X made way more power once a decent tuner had a look at the MT8. Also have a look at your battery voltage when driving next at night. My car with the MT8 went from a pretty strong 200 odd rwkws to a doughy piece of lard as the battery voltage got into the high 11s as the ignition system gave up the ghost.

A new battery, and a big ass Bosch alternator had the thing putting the numbers down way more consistantly. Are you sure your tuner knows his way around RBs running Microtecs?

Not sure of his reputation with microtechs and RB's, it isn't a very common combination. Currently tuned by Greg at Autosport Engineering in Kirrawee (Sydney). THINKING about going to Thornleigh Cylinder Heads (huge reputation, but pricey) or UAS.

Would getting rid of the cat give any worth-while gains though? My voltage sits on around 9.9 i think(or 12.1, i really can't remember). Not sure about the air temp compensation, i'd like to look into it though as i want to explore every single possibility to extract more power out of this, long term project, hoping to crack 300+ rwkw from RB20/24(maybe).

The biggest downside at the moment is that i got the car with the microtech already in it, so i can only guess what the previous tune was, and what it has and hasn't got, so in a way, im starting from scratch, well, a more painful process.

If your battery voltage is dropping that low then i would hazard a 6 pack on the fact that your car isnt making the power it should because the ignition isnt working 100%.

The MT8 was very sensitive to battery voltage, and the igniter drivers in the ECU needed a good strong voltage, otherwise the car ran like adog. The car was always a bit doughy, the car never really made much power considering all the gear on it. Then one day i noticed on the handset at night that the voltage was lower (stereo going, lights and windscreen wipers) and the car was slower then normal.

A few questions to the right people confirmed that they need strong 12V+ voltage...the car was great once with a new battery/alternator and a good tune from Quickfit in Hornsby

so are there any other places you can reccomend to tune a microtech on an RB20 in sydney? Reasonably priced too (can't get it done yet as i just bloody forked out $1100 for work on the car including a full dyno tune :D)

I havent tried many, everyone has their favourites. But i did find Quickfit (NSW Autronic dealer) very good at getting my car to drive a lot better and make better power...cant really remember what i paid, it was 6 years ago :D

Then again, it could be tuned perfectly, and thats the power it makes?!?!?!

*shrugs* i doubt it. It runs very poorly on coldstart, i know microtechs are notorious for this, but it can't be THIS bad, i don't know, i just have my doubts, i know it can be more finely tuned, well, i have a gut feeling.

Try unigroup at girraween. They have tuned a lot of rb powered cars and offer good prices.

As the car is running, it will likely only be a bit of a touch up (depending on how the current tune looks) so you could get a surprisingly cheap quote.

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  • Latest Posts

    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
    • Nah, that is hella wrong. If I do a simple linear between 150°C (0.407v) and 50°C (2.98v) I get the formula Temperature = -38.8651*voltage + 165.8181 It is perfectly correct at 50 and 150, but it is as much as 20° out in the region of 110°C, because the actual data is significantly non-linear there. It is no more than 4° out down at the lowest temperatures, but is is seriously shit almost everywhere. I cannot believe that the instruction is to do a 2 point linear fit. I would say the method I used previously would have to be better.
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