A Boy's Love For His Rb20

[turboedsloth]

did it overboost? Mine did apparently they are to efficient.

[Roy]

No, just killed response of the setup From what i read and was told was expecting a 200-300rpm improvement in response, not drop off. Oh well, will be interesting to see if it drives any different, but not encouraging that seems to lag behind orginal Greddy manifold. Maybe i should rip all this shit off and not mess with something 'that aint broke'

Lets hope its something like a restriction with plumbing the gate back in, shitty spring and opening of gate too soon, crappy BOVs or a leak somewhere. Lets hope

[SimonR32]

No, just killed response of the setup From what i read and was told was expecting a 200-300rpm improvement in response, not drop off. Oh well, will be interesting to see if it drives any different, but not encouraging that seems to lag behind orginal Greddy manifold. Maybe i should rip all this shit off and not mess with something 'that aint broke'

Lets hope its something like a restriction with plumbing the gate back in, shitty spring and opening of gate too soon, crappy BOVs or a leak somewhere. Lets hope

checked compression after the few years of abuse and sitting gathering dust, maybe the little 20 is flogged out?

[fatz]

nasty

[spranga]

Love this thread. Go the silver RB20!

Edited August 13, 2010 by spranga

[Gerry Giraffe]

Hay mate,

Great read but by the sounds of it your 20 might be a bit long in the tooth, maybe time for a slight change??

http://www.lewisengines.com.au/prod158.htm

lol

[Roy]

Well after a weekend of driving around DECA there is nothing wrong with the engine. Plenty of head scratching has revealed there are a few little tweaks in teh setup that we will try whcih will improve things. Need to run it again onm the dyno with 17" wheels and find some Shell 100 equivelant fuel as my last tune I am comapring the current one too was on 100 and took a lot more ignition. Will also try dumping the plumb back to see if we find some more top end with an open gate exhaust.

So, at a minumum there is no performance improvement from changing to the 6boost manifold. But it seems that there isnt the loss in performance that I first feared.

So engine is still fine, even after some 8,400rpm limiter work on the skidpan. I think it will need the 25G to break this engine....but no way I am going to give that a try considering that all the changes have netted nothing in the way of improved performance, only hopefully reliability looking forward.

[TiTAN]

if it doesnt break you arent trying hard enough

[SABBAi]

Great stuff Bris. However, I must say that you need to ditch the plumb back.

Brisby and Gate is to a 20, as Dash 5's and cam gears are to a 26.

[phunky_monkey]

True, that plumbed in 'gate was all a bit suss... open it up

[Roy]

Yes, without the titanium exhaust on the car the whole plumb back thing has left me feeling a little empty inside

So, below is the plot. The changes are:

Old Tune-Setup

100RON Shell Racing

HKS Type S Cooler

Greddy manifold and Type R gate

3" dump pipe and atmo gate. 3" straight pipe for cat on dyno (to eliminate the cat as a power killer during tuning)

NewTune-Setup

98RON Shell

ARC 100mm GTR Cooler

6boost manifold and Turbosmart Hyper Gate 45

3" off turbo into 3.5" dump with plumb back gate. 3.5" straight pipe for cat on dyno (to eliminate the cat as a power killer during tuning)

So you can see there is a dramatic change in response which seems to be mirrored in the power the thing makes. We are reving it 500rpm harder, but even still there is a possibility that we have changed the final gearing by running different size wheels/tyres. But we dont think thats the case, but will trial a few things here as well

So will throw on the SBC ID and see if an EBC can do a bit more for response. Open up the gate to see if its hurting top end. Throw some RON100 in it and there are also a few other things I want to try before throwing the 256/8.5 Poncams and Plazmaman Plenum on

[NickR33]

Roy what have you done!

better spending the money on the chassis to get it handling really well IMO... your engine/turbo setup was never an issue was it?

[toddlls]

Nice write up Roy, plenty of useful info for me in here, wouldnt mind seeing this beast in action 1 day

[SimonR32]

We are reving it 500rpm harder, but even still there is a possibility that we have changed the final gearing by running different size wheels/tyres. But we dont think thats the case, but will trial a few things here as well

That's what it looks like to me, a little later on the power and a little later making peak power...

I would also assume the extra timing used with the 100RON fuel would have made you able to smash more timing in the mid range and create better response

[Roy]

Roy what have you done!

better spending the money on the chassis to get it handling really well IMO... your engine/turbo setup was never an issue was it?

I wanted to fix some of the piping around the turbo outlet etc, and the Greddy manifold was getting old ad everyone pulles their d1cks about how the 6boost manifold would perform better then even a Greddy manifold. So the idea ticked enough boxes ...and the main thing is the 6boost manifold should work well for a number of years.

I think I have gone as far as I want with suspension, thought about all those funny doo-dah arms, but honestly, it would be prety easy to go backwards and dont want to pay 2k in labour for fitting and a wheel alignment. Does need to be lowered a bit more and then I will try to get a better alignment into it.

Plus, I was hoping to go 25G and have a +300rwkw stock RB20 But think that setup will have to wait for the built motor

[Marlin]

Roy, just for interest sake, I pulled the engine out of mine last night after I boiled the oil at Lakeside and did a big end, and she looks pretty good!

#4 big end looks to have failed, giving enough bearing play to break the piston oil squirter off.

Crank/rods look good as gold. Compression is a little jumbled though, with mins and maxs differing about 15% instead of the 10% that I normally abide by.

Gonna give her a full birthday though, just wish the rules would allow some more freedoms to run one of your turbs!

[JAGR33]

This car has too much history, would never part with it Troy if I were you.

Remember the very first time I saw it at a Winton fun day many moons ago....

It hitched a ride with me back to Melbourne, didn't look healthy at all...

Ahhhh the memories....

Very much look forward to seeing it back out at the track, can expect some very decent times.... for a RWD....

C'mon!!! Get it back out there!!!!

[Roy]

LOL, ahh that was a funny day. You and Geoff really helped me out of a bind! Its funny. I look at those pics and I honestly think it looked better with those wheels, factory paint and bodykit then it does now What do they say about dont fix what aint broke! LOL, though I suppose it was broke

And it will be back on track soon Jack, early October actually. But before then I need to get some practice, so next month doing a track day at Silverstone, two days at Nurburgring and a day at Spa. Should get my eye back in

[JAGR33]

LOL, ahh that was a funny day. You and Geoff really helped me out of a bind! Its funny. I look at those pics and I honestly think it looked better with those wheels, factory paint and bodykit then it does now What do they say about dont fix what aint broke! LOL, though I suppose it was broke

And it will be back on track soon Jack, early October actually. But before then I need to get some practice, so next month doing a track day at Silverstone, two days at Nurburgring and a day at Spa. Should get my eye back in

Don't be hard on yourself mate, it looks HORN at the moment.

Practicing at some of the worlds best tracks??? Can't beat that.

Give us a hoy when you're back in town....

[Roy]

Well I am now back in Aus. So this weekend will be getting RE55s fitted to my TE37s, checking the brake clearance for the brake setup and also finally getting around to prepping my new rocker covers. While swapping the rocker covers will try the new plenum and baby cams

Edited September 23, 2010 by Roy