sounds very similar to my engine spec.........apart from the turbo,very nice

my oppinion on this thread is although fuel has missed a few points i think what he is trying to say is why does it matter if the power is up the rev range, you are either pushing it or your not, so if your not you drive of boost and if you are you drive on boost and poviding that boost is there once you change gear it does matter what turbo it is. however on the flip side paul is trying to say he doesnt want 2shift down from 5/6 on the motorway when he needs to over take as john s has said its about flexablity.

all i can say (others have said it) paul is try and get out there and drive a few (i am sure owners local to you wont mind) i personnally run a gt28rs with the 0.86 housing, i have been driven cars with gt28r,superspools,gtir,gt28rs 0.64, gt2871r and i find the gt28rs with the 0.86 housing offers me the balance I FEEL suits me.

i would say that there is very little difference between the 0.64 and 0.86 (can not comment side by side but at least from a driving point of view) gt28rs's and because there was very little i decided to say stuff it i want a few more ponies

i think the gt28r/gt28rsr's are probably slightly more flexible but i personnally dont think the difference wants losing out in the power stakes. I will say though in my oppinion the gt2871 just pushs the power a little too far up the rev range for me but again its all about YOU and your driving style, but i dont regret the gt28rs 0.86 one bit

if that helps (probably not

He Paul ! of course it helps ,good to hear as many opinions as poss,thats what this thread is all about
So your opinion counts as much as anybody else,especially as you have tried a few turbos already

Paulr20vt - what power u got from your setup?

Ross

ESSAY ALERT!!!

@Paul... glad it helps. (more below)

@h2yper... I wish I knew, I have had the car off the road for around a year, just playing and testing with different setups, I am not going for all out power as I also what something that’s driveable aswell as being a bit of an animal, I had a spell of a week or so with it on the road and it feels very strong, but have no power figure + I think bhp is just for bar talk and drag strips, not on the road, obviously its nice to have more (I am aiming for at least 350bhp) but I feel the real word differences are minimal.

The problem with the roller bearing turbo is not really lag (the turbos we are talking about are still babies in the turbo game) but their delivery, granted there is lag but I believe it more the way it feels... my examples.

I have a passat tdi sport which has a tiny 130bhp (obviously more torque), now this 'feels' quite quick because of how flexible modern day diesels are BUT more to do with small turbos imo as diesels don’t have the revs for larger turbos. Obviously they inherently have more torque then petrols but the sensation of speed is still there even with 130bhp (to be fair I think mines been remapped, but the principle is still the same).

As a standard car we are use to the punchy asthmatic small t28, which means we are used to mid range poke and a heavily tailed of top end, when we replace this with a rollerbearing turbo we totally change the characteristic of the car into a more naturally aspirated delivery, but our mind and body are still expecting that mid range grunt, so we feel disappointed, even though the midrange is still bloody shifting and would still probably kill a t28 or t28hybid!!! The rollerbearing turbos are so smooth that it irons out delivery and makes us feel as if we are going slowly when really we just killed a Porsche carrera.

In my opinion, if you could lift someone up who has never driven a coupe and put them in on with a gt28rs or similar I don’t think they would get out and say “shame the power is all top end”, I think they would get out and say “f me that’s fast and so linear”.

This might sound like I am siding with fuel, I am in part but do think he has taken it to the extreme, I don’t think you would ever notice a massive change in lag from gt28r to gt28rs 0.64/0.86.

I would finally add (don’t worry the essay is nearly over )that I prefer the drivability of the larger gt28s over standard turbos, before I would pull out of a junction and even if I didn’t want to that turbo would sometimes kick in when I didn’t need if, where as with the rollerbearing its pull out smoothly like a decent v8 (kind of )

As I said make a plea with owners to test pilot there cars

Fair play to you. At least it sounds like you have thought it through.

However, i dont feel that compremise has to be made. Im hopefully gonna get some proper graphs this week to show good spool up and peak power. Yes, i drop a gear when i wanna race someone but having that low down grunt is very useful around town.

I never find the turbo comming in, as the off boost performance (below 2500rpm) is very strong and torquey.

Ross

you're going to have it mapped?

or you simply go for a RR run to see how it fares?

V.

Something like that

Ross

very informative post and well put thanks Paul,gotta agree with a lot you have written.

In that case hand over the RSR

Ross

still toying with having both rsr and rs and trying them both out.

h2ypr-just noticed you have almost 8000 posts jeez,do you carry your pc around with you

Nah just talk a load a sh*te.

Ross

p.s im actually at work just now. Sunday's are dead.

i must say i havent driven an rsr but expect it to be between the gt28r and rs (obviously) if you have the rsr there and in your hands then maybe you should stick with what you have.

drive some

I doubt there's tat much difference between the RS and RSR? The money you would spend on an RS could go towards all sorts of things, like a S3 head!

He has a stage 3/4 head i believe!!

I would run with the RSR.

Ross

DTA, OMEX, MoTec, Pectel, Autronics, you name it cannot reduce the lag down appreciably unless you are using antilag - the std ECU is just as capable at mapping to support good spoolup as any aftermarket ECU - that means doing stuff like throttle enrichment and throttle movement based advance adjustment. The only way you can reduce the lag is engine work be it higher compression, better head flow, advanced inlet cam or whatever external breathing like variable inlet length etc.

Std sump is baffled pretty well - lessons learnt from the 16VT engine, not sure unless you can properly model it that you can do much better more likely to do more harm than good to be honest. Only effective way to improve it would be either something like accusump or dry sumping

http://www.fiatcoupeclub.org/forum/ubbthreads.php?ubb=showflat&Number=464710&gonew=1#UNREAD

have a look here paul, there is a ultraspool (which i believe is close to the rsr) v rs map of power and torque, might give you some ideas

Paul

the solution must be always SPOOL UP and LESS POWER......




















http://upload.spyro.it/public/8549/Foto%28625%29.jpg

I have no experience of any turbos other than T28 and Hybrid T28s, but I think this one knocks it right on the head.

One of the best features of the 20vT is the low-down torque. After driving pretty much anything else (even 355s or M3s) most owners comment on how 'peaky' the power delivery of these cars is. We get back in the coop and love the low-down grunt. Any owner going from a T28 to a GTxx is going to worry about losing that wallop of torque well below 3,000rpm. If the coop had never had this, you simply wouldn't miss it.



I'm actually really suffering from this off roundabouts lately. Just yesterday I pulled out onto a roundabout pretty quickly behind another car to get into a smallish gap. The car infront slowed suddenly and just before I let of the throttle, boost arrived quite savagely, then went just a quickly. Everyone in the car was thrown all over the place by a 4mm of travel from my right foot. It really is sooo annoying, worse than ever after the FMIC & SI.

I have in my hands a nice new RSR,but i think maybe the RS will be the turbo of choice

Going onto one of the bigger Turbo`s (ie GT2871R ) will, for me anyway, push the power up to high.

So what difference do you reckon between RSR-RS.............I`m guessing, 20-25 bhp more and(with my mods)maybe only 200-300 higher for spool up ?

If you can be bothered (more just for the fun of it ) what do you reckon on power output for my engine with rs/rsr( chargecooler will be removed)......probably go for around 1.6-1.8 midrange tailing off to 1.2 redline

Looking at 007s results in the RR section, an RS will have probably caught up with an RSR by 3,500 rpm, but the delivery is a little more savage (i.e. on/off). Not sure about the top end, maybe 20 BHP, maybe not. Personally, I wouldn't bother swapping if you've got the RSR already.

What Turbo would you recommend then Trappy? I love quick spoolup.

I'd recommend any turbo that doesn't do this. My T28 GTiR spools up to max boost of 17psi at 2,600rpm. I has a real on/off characteristic though and can spoil normal driving when it comes on suddenly just before changing up. I like the sound of these GT28r/rs/rsr jobs with the more progressing spool-up and bigger top end, and considering the money these now go for, I'd go for one of them if my current turbo went again.

When you getting your rolling road dude?

Ross

I don't think it's worth moving from an RSR to an RS. I think the RSR is better in most respects having driven both. The RSR loses a lot of the off/on-ness of the GT28RS. The power difference is relatively small at the top end but has a decent improvement in spool. Marcus' car made 380BHP with an RSR and Barbz' made 392BHP (I think it was) with a GT28RS so for 10BHP I would take the better spool up every day of the week as well as the better behaviour (less off/on)

JohnS : Thought marcus made 370?

Ross

It was 378. Also, I'd definitely agree with the on/off comment above, I find the RSR a little on/off as it is, looking at recent RR results the RS seems to be alot worse in this respect.

Me? I'm going to the Surrey RR day on the 10th

having not driven an rsr i would take john s's advice, as i said previously i dont think i would not use an rsr in favour of an rs if i had already bought an rsr, but would probably get the rs over the rsr if i was buying new again

I'm heading for the GT28R (god send me the money please!).
What's the max power anyone measured with this turbo? And what was the mods?