Finally got a weekend to drive the coop round and get a RR with the new bits on

Well what can I say

At 1 bar boost the car is very nice to drive, smooth delivery of power and very easy to drive. When I put my foot down the car just pulls away (whether round town or some open road) with ease and no sudden kick. Although it feels smoother than the standard turbo, it also feels quicker, it just appears to get there with less effort.

At 1.35 bar boost it’s a different beast. 1 bar comes in at under 3000 revs then it very quickly climbs to full boost which is held to redline.
1st gear is a bit uncontrollable, but 2nd and 3rd are just great and 4th at the higher speed just makes most things vanish in the rear view mirror.
I was a little worried about the not being able to put the power down in 2nd, no problem however, putting foot to floor at 30 gives almost no spin (uniroyal rainsport tyres) on a dry road.

The rolling road went well, with only one concern.
At 5000 revs it starts to run rich getting to 10 at the limiter
Now this is better than lean, but what would the options be to correct this. Could GrahamL produce a Gtec2 with less fueling at the higher revs or do I need a unichip? I would of thought that the correct fueling would see another 10 – 15bhp, however more important to me is how damaging this amount of over fueling will be. I would appreciate your thought on this.

Results.

315 bhp and 253 lbs/ft @ 1bar (282 bhp at wheels)

350 bhp and 292 lbs/ft @ 1.35bar (321 bhp at wheels)

oops, forgot graph

All in all I’m very pleased
(now to start thinking about what’s next along with clutch, cambelt, respray, the list goes on )

Mods
Gtec 2, Straight Induction (Barbz), Pro Alloy FMIC, 255 Fuelpump and uprated wiring, GT28RS Turbo, H&S Downpipe, De-Cat, Electronic boost controller (2 settings)

Forgot this bit.

I have done a comparison of accelerating from a steady 35mph to 80 (IIRC)

a. S/S Cat back exhaust, K&N filter, Gtec1, prv at 1.2 bar (the rest standard).
b. S/S Cat back exhaust, K&N filter, Gtec2, prv at 1.2 bar fuel pump and wiring mod (the rest standard).
c. S/S Cat back exhaust, Gtec2, prv at 1.2 bar fuel pump and wiring mod, straight induction (the rest standard).
d. H&S downpipe, decat, S/S decat back exhaust Gtec2, fuel pump and wiring mod, straight induction, GT28RS, electronic boost controller at 1.35 bar

They all came in at about 7.1 – 7.2 seconds, just goes to show that the differences are not always that great.

Great result! What turbine housing are you running? 0.64?

Congratulations, very nice results , nice torque curve, looks like the 0.86 GT28RS??

You're right running that rich would reduce power by 10-20 bhp, my car also ran rich ~10 AF with the GT28rs.

tbh you need a mappable chip to reduce the fuelling, something like the Unichip may well suit your needs, unless Graham can help you out, but it will always be a bit of a guess for Graham whereas the Unichip will be tailored particulry to your car.

joe

Its a .64 housing. I went for that due to al the comments about the how laggy the the 86 could be (im not so sure to be honest).
Thanks Doctorfrag, you a probable correct about the unichip so i'll ask my RR place about the cost. I will also drop GrahamL a line to get his views about his chip, don't ask - dont know.

nice result. shows how choked those big blowers realy are... hmm, love to get rid of the superspool now

very impressive results. well done

Rgds,

Sean

V666 you dont say what Gtec your running, im guessing a Gtec2 for that kinda excess fuelling or novitech style one?? Guess it shows your injectors are in top nick as well

KP he's running a GTEC II.

Can't wait to get mine sorted now then, thanks to KP its all fitted, just need to tweak the boost controller and adjust the settings!

Off topic slightly, but how annoying is that whilstling noise mid accelleration?!

Me thinks ill need to pester Mr Gtec for a Gtec2 depending on the results from the LPG setup

And the whistling is ace for partial throttle to just annoy people but doesnt happen at all to me on full boost.

Nice results there Tim . A Unichip seems like a good next move, and it will definitely give you even more power with the fuelling corrected. Mine gained 25bhp at the top end just from the Unichip, but then it was overfuelling quite a bit !

Good to see the FMIC and downpipe doing their bit . Maybe you need some C&Bs now ....

Phil

What exhaust did you use - I'm most intersted in the bore rather than anything else....

Good results - nice one! Now get it mapped....

Startling figures, no ? I thought 350 bhp was over the limit for standard internals ?

Good luck Tim, I'm still really impressed with that power figure. Exchange the 28RS for a 28R, and put the standard cat and rear box back on, and our cars will be very similar. Looking forward to getting it back even more now

Suba - The H&S downpipe throttles down from 3" to 2.5" at the cat, so I guess that Tim has a 2.5" cat-back system .

Phil

That would be right, thanks. Sorry, brain just died and would not remember the size It happens sometimes, a sign of too much work I rekon

315 bhp and 253 lbs/ft @ 1bar (282 bhp at wheels)

350 bhp and 292 lbs/ft @ 1bar (321 bhp at wheels)

Might want to edit the bottom one to say 1.35 bar

lol
edited now

I've just noticed that on those figures your car has 'gained' 39bhp @ wheels yet only 35 @ the fly...

Are nice curves though m8, so much be fun to drive

Is anyone else doubting the figures? The mods dont add up.
No offense to you v666.
Ross

Nope, not doubting them at all.

Some roads are more generous than others yes, but its a monster.

Tranmsission losses stated are not possible. 29bhp off 350 is about 8.3%, which is less than half the average Coupe transmission losses (average is about 18% - 20%)

Each rolling road is different, so never easy to compare.

There's not been many GT28rs rolling roaded, but at the top of my head

(0.64) housing

330 bhp
333 bhp
335 bhp
350 bhp

(0.86) housing

338 bhp
350-360 bhp

Most of the recent info has come from PTS and has proved a bit of a becnhmark for a lot of coupe owners, but all sorts of factors will change the results, such as atmospheric conditions ,oil temperature, tyre temperature and pressures etc, so even on one day doing 10 runs, you may well get 10 different figures!

I admit that the results are a bit 'high', but its not to dispute them, the only way to more easily compare would be another rolling road day....

Joe

Just personally find it weird, that people before PTS with simliar mods have figures well below the more recent ones. The thing that kinda rings alarm bells for me is the torque. For that kinda bhp i would expect higher. That kinda torque figure is usually associated with kinda 300-310 bhp.

Ross

I agree, the results could well be high. The guy who ran the car did say that they are a little higher than another RR that he knows. Both of them claim to be accurate so who knows.
I think its more important to keep to the same RR when looking to see what difference is made after changing something to get a true representation of the effect it has.

I have no objection to going to PTS as I think it would be good to get a comparison against other coops on the same RR. Its just time, as PTS are a fair drive from somerset.

One thing I can confirm, it is much quicker than standard

maybe i'll talk to PTS about a unichip, might be worth the drive then

To be honest i dont think the unichip would provide extra power from your current setup. IF the figures are true then that car must be crazy to drive!

Ross

A unichip WILL improve your car. If it's running rich then you will get at least 10bhp and improve your car's performance further. As for whether or not you will 360bhp or not well I guess only one way to find out.

Not after more power, looking to sort the overfueling at the top end.

and some RS car figures from hall of fame for comparison.

Bursa 330 bhp 284 torque
Jari 357 bhp 307 torque
Doctorfrag 335 bhp 300 torque
Dan20VT 328 bhp 308 torque