I've searched high and I've searched low (including NASIOC) for inspiration but the truth is I'm no nearer making a decision on whats best for the car.

Car = Sti8
Current mods = ppp with tsl 333 remap; panel filter
Current power = 332 bhp/ 290lbs torque (Well Lane Rollers)
Mods to add in June = RCM 3" downpipe; Revolution 3" cat back exhaust system; ported and wrapped headers from Harvey plus Harvey up pipe; Andy Forrest Tek 3 remap.

Now I wasn't going to bother with the turbo at all initially but if I dont do it on this remap I never will. There will be no track days or sprints so its strictly used as a daily driver with point to point thrills the key (already have AST suspension etc).

Is it better to go for the mid range punch of the 18G or the top end grunt of the 20G or are the differences that small you wouldn't really notice on the road. Driveability the key...............

Want to be sure before I splash the cash so any experiences welcome.

Rob

 

I was going to give a biased opinion, as i have the 20G albeit on the 2.5, but i'm gonna be honest and say to go for the 18G.

From what i've gathered and been told, the 18G is much better suited to the 2 litre, as an everyday car.

IMHO, you couldn't go far wrong from a quick email to AndyF or Pavlo/Zen. They are dealing in these turbo's, so i'm sure they would be happy to answer all questions in regards to the 2 mentioned turbo's!

 

Thanks for your comments mate I've read your spec with interest over the last couple of months and appreciate your honesty.

Andy has confirmed both would be ok with the "18" better for mid range which I guess is what the real road is all about. Think this is the one I will plum for as I have no intention of modifying any further beyond this point.

Thanks again

 

Good choice.

 

i have no intention of modifying any further beyond this point

yeah right! you have got the bug so just carry on

dont worry your wife is not on here, so you can tell us

 

this should help all you need to know about the turbos in question!!!


http://www.andyforrestperformance.co.uk/16307.html

 

LOL at Mark above.
My wife actually likes motorsport so knows the 'tell tale signs', so they will catch you in the end

you are doomed.
Graham

 

lol mate. No thats it for me. Learnt the hard way after putting around £10k in my Classic. Not something I want to repeat tbh. Plus next mod would be a FMIC and for some reason I just dont fancy going down that route.

Plus its the wifes money I'm using..............sssssssshhhhhhhh.

 

Thanks for the link mate. I was hoping for some "on road" comparisons between the two but think I've made up my mind.

Thanks again.

 

Hasn't she kicked your *** yet mate?

 

yeah no worrys happy to help.

 

Don't know if this helps. It is a road dyno power/torque trace from my own WRX with an 18G and 20G
As you can see, if you use the higher rpm range then the 20G becomes more worthwhile, especially if you run an early sti which revs to circa 8k, midrange the 18G wins.
Actually quite difficult to tell the difference between them on the road via the seat o pants meter !

Green = 18G power and torque. Red = 20G

 

Andy out of interest which turbo do you have on the wrx now

 

The 18G is back on and running 1.7 bar midrange. The above tests were at 1.5 bar flatline.

Andy

 

Thanks for that Andy.

Experiencing the on road characteristics first hand (and of course mapping other vehicles) which unit would you plum for on the sti? This will be the last mod so I'm not buying with further additions in mind at a later date.

If its strictly for the road would you conclude the 18G fits my purpose better? I note there have been reports of surge issues on the 20G which I appreciate may not be true but again this makes me lean towards the slightly smaller one.

With the prices being exactly the same I just want to make sure I get the right one and avoid any undue disappointment.

Plan to order one or the other with you over the weekend

Rob

 

I would say that unless you are looking for a slightly bigger dyno number and fitting a fmic, then the 18G would be more appropriate for your spec.

Andy

 

1.7 bar on a WRX engine thought they couldn't take this much

 

How much power and torque is running Andy?? I was seriously thinking of putting a 16G on my 2002 WRX but if it can take an 18G without too many problems, then happy days!!!

Can you let me know how it's running please Andy??

Cheers

 

I have an Sti v3 with 20g that has run an Sti V8 TMIC and now a Hybrid FMIC, both times with 'supporting Mods' and most importantly, mapped by Andy.
The car is primarily a hill climb car so gets 'stretched' hard in competition, but not on the road too much.

The 20 g can drop off boost at the critical 3500/4000 on the road and lags quite badly (it feels) but keep it boiling and the car is ballistic.

I have never tried an 18g to compare, but I can see from those graphs the 18g being the better 'all-rounder', especially with a TMIC in place.
Can't help but think that you need an ECU re-map to get the best, and certainly 1.7bar!
Not sure if this vid may help, but wait for the car to appear in the distance in the farm track, it is in second, just fallen off-boost and in the wet (despite appearances), it then spools up /into third and charges forward and responds great after, i kept it on the boil.

I'd follow strictly Andy's advice, you will not go wrong.
Graham
http://www.dropshots.com/day.php?use...1&ctime=004534

 

Cheers Graham. I always follow your threads with interest and value your opinion.........your to blame for the AST's on my car!!!

18G it is. Looks like I'll be belling Andy over the weekend.

Thanks again.

Rob

 

Graham.

 

I have not dyno'd it but a very similar customers 02 WRX just made 368bhp and 333lbft torque running 1.45 bar on an 18G. This car is used regularly on track so was mapped with a appropriately large safety margin.
My own WRX however never sees the track (well apart from 1/4m) so runs a more aggressive map and higher boost

There are quite a few new age WRX's out there that have been running 18g's for over a year without issue.

Andy

 

Wow..... has it been a year already.

No issues with the 18g whatsoever..... fantastic

Martin

 

shall i sell my 20G and get an 18G decisions decisions

you bas%*rds you got me thinking now.Whats more suitable for classic STi rev range?

 

TC:
Know the feeling!
you can go on and on can't you?
Must admit I went for the 20g thinking my hillclimber would now have a 2.2/2.5 in it so be ideal....

Not changingit now.

Graham

 

I havent had the 20G mapped in yet Graham its being done in the next 3 weeks hopefully so i guess time will tell.

Bloody cars its an endless money pit

 

I would still use the 20G on a classic Sti 3/4/5/6 due to the higher rpm range.

Andy

 

Thats good enough for me

 

What spec would i need to keep up with an SL600??

 

iirc the SL600 does the 1/4mile in 12.9@109mph

Probably a little less than 340bhp in a classic would see it off