Andy if Graham ran a group N turbo restrictor wouldn’t that up the torque like the big boys in the PWRC??

 

Graham, my car has 3" system, one box in it, built by myself, and I come in way under Blue book limits. Next season I'm coming out without a silencer, mainly a weight issue, I think it will still pass.

---john---

 

Re rolling roads.

Most rev counters read about 100 rpm high, and most speedometers about 10% high depending on wheels/tyres, pays to check the car with GPS and take the figures to each rolling road, I normally check 60mph in 3rd,4th, 5th which covers most eventuality's

bob

 

Thanks for the inputs; all interesting, especially the restrictor one, never thought of that.

John:

The midland hills are all in rural locations next to 'expensive' villages with very expensive people recently moved in many who hate the idea/noise/irritation of hill climbing. Noise is a real issue hence the regs set at 1.8 Db max @ 1 meter @ 45 degs.

This will get tighter as some of the circuits have recently found.

The worst noise is the sound of screeching tyres off the start line, not that my Sti can do much of that!

Graham.

 

We are noise checked at most event, car went up from 92db to 96-98 when the 2.5 went in so still way under what you are talking about.

---john---

 

Graham

1.8 dB(A) at 1 meter ... very very quiet .. you may mean 108 dB(A) ??

PS - quiet countryside is 50 dB(A) and a quiet room is about 60, 3 dB = twice the loudness!

 

Sorry, yes you are correct! 108 max.

At Shelsley Walsh a BRM V16 ran at 138dB, bought a new meaning to 'ear splitting'....

I usually win the unofficial Quietest Car of the Meeting award.

 

So, how to get the torque to a high level and at a reasonable rev level?

Anyone care to comment on adding a restrictor (rally style) to jump the torque?
I wonder if an 18G would be better than a 20g for the 2000cc Impreza engine?

If the restrictor is down stream of the MAF, would I need a re-map?

Graham.

 

If Fuzz is reading this:

What do you think contributes to your engine holding such a great torque curve?
How do you hold the boost that long, even increasing it over the rev band?
(I refer to your web site Andy).

Graham.

 

A restrictor won't add or 'jump' the torque.... the old groupA cars used to run 2 bar boost to get their torque figure, i'm sure i read the WRC cars now run 3 bar .

Why restrict an engine that doesn't need to be??

Tony.

 

Graham:
If you did add an restrictor then I would get it re-mapped, to get the best torque from it (and to be on the safe side )

 

Surely a restrictor would be specified to limit power as with limiting sizes of choke venturis, throttle bodies, etc? Counter productive to what you're trying to achieve.

2.5 on the horizon Graham?

 

Don't like the sound of the last line....
But I know it makes sense....
Gearbox first!
Nice to hear from you !

Graham.

 

Never really thought much about the idea until Bob Rawle mentioned it(above).

I think a 2.5 would be the answer to it all really. The 20g turbo would be perfect and all the other bits are right for the job. If only the trans was man enough.

Wonder when this all stops? (when I beat the EVO!)
Graham.

 

you don't want a restrictor, more boost is required. The reason the rally cars can make the torque, is that they can run very high boost (2.5bar at sea level) at very low rpm (below 3000). The restrictor allows the (purpose made for restrictors) turbo to run without compressor surge at low rpm.

Don't go fooling yourself with rolling road graphs if they don't match the running conditions of the road, which well lane for a start will certainly not.

Paul

 

I don't know of ANY rollers that can match the running conditions on road. That's one of the reasons my car has not been on the rollers in its latest spec.
The other reason is I'm sure I'd only be dissappointed with "the number" compared to some other claims flying around

Andy

 

lmfao.. ill aim around 600 for mine as im sure you would for yours

 

Appreciate the comments, as ever, I have a lot to learn

The car goes like stink, catch it right with the 'lag'/boost climb point and it is truely fabulous. That is quite hard to do when the speed is too fast for 1st and too slow for 2nd. I need a box with a taller 1st and stock Sti 2nd.

The hill this weekend at Prescott is a real challenge for the car and it's gearing and I need to get into a corner faster so 2nd is more responsive or get wheelspin in second to generate a variable gear to get the engine 'up' and the car going.

I need a 2.5
I need a good box.
I need a way to beat the EVO this time.

Graham.

 

So how do they get the torque up in group N then

 

Good mapping on GEMS?
Graham.

 

And how much torque have they got then?

 

Just to answer Bob'5 question on the tick-over from my Suspension thread:
Bob, the original problem of cutting out when the engine was getting warm was 'fixed' by adjusting the throttle cable to get the tick-ove just high enough to prevent stalling in the first 5 mins of running from cold. This gives a good 800 rpm when hot.

Today the engine runs as:

Cold start the engine just ticks-over with out assistance, after 2 mins the revs climb to about 1100 rpm and after a further minute drop slowly to 1000.
I then drive the car with normal care while warming up. After about 5 mins the car is perfect. During the 5 mins you might get it to stall instead of ticking over.

Hot start is perfect, instant and steady at 900 rpm ish.

Can't be bothered to have it sorted by Andy as the engine is great when warmed.
Carman had a GEMS on his stock Sti RA V3 hill climber and that was evil on cold start, but was very nice when hot.
Hot start was a bitch too, needing lots of throttle jabbing to keep it going.

Hope that helps.

Graham.

 

Sorry Bob, one more thing, can you tell me more about your gearbox please, pm if you wish.
Graham.

 

I see. Mine is different problem, which I feel could be patched up by adjusting the throttle cable as you have done, although I have been advised not to.

Cold start is fine and as is cold idle. Warm idle goes too low after about 25secs.

Have changed MAF and lambda without change.

Just thought it may be worth checking with you as I recalled you had idle issues also.

Re: Gearset - http://bbs.scoobynet.co.uk/showthrea...=439647&page=5


Cheers,

Bob

 

From what I've been told (and seen) GPN cars also run with a restrictor and do run more boost (about 1.6bar iirc). On normal fuel with standard turbo you could be looking at about 260-280bhp and 320-340ft/lb. But they don't rev that hard.

I've been in a GEMs mapped GPN classic before and its nasty on the road, on off throttle with nothing inbetween. But get on a stage and it works very well and you're either on the power or on the brakes. You're never cruising on constant throttle.

Dave.

 

After a cracking season hillclimbing and some long hard thinking, the Sti will only have a heath-check and some very minor tweeks over the winter of 2005.

It is hard to justify a 2.5/6 speeder when I came first in class and second in Class (beaten by an illegal car).
Can't sit on your laurels though, so some work has already started.

By chance, an email chat with AndyF has kicked-off the look at the engine.

I intend to run with a sports cat next year and straight Optimax with no NF booster. The regs for the hillclimbs are getting tighter and tighter, so I need to get the car arrow straight.
Andy has a little trick for the TD 20g so the plan (today) is to send the 20g to him and do the d/pipe.
I must be getting used to these bloody cars as the parts fell apart in my spanners/hands, and I thought you might like to see what has gone on over the season 'inside' so to speak.

The Sti v8 TMIC slipped off and it was pleasing to see that it was bone dry inside since i did the engine breather mod, and that there were no signs of leaking despite fear it would at 1.4 bar



Next was out with the 20g. I was waiting to see if the gaskets were leaking at all (these were Subaru gaskets, not the Gruppe S ones)
The turbo itself is in perfect condition, no leaks, no play in the turbine shaft etc

Top of up-pipe:
no blowing black soot at all!
Turbo out and a look aroound the mating faces:



Note the heavy yellow 'coating' in the wastegate, and the d'pipe too:


Next off/out was the helix/Gruppe S up=pipe. I took this off as the wrapping had suffered badly and I was in fear that the flex section was ruptured and the gasket might be leaking, no fears!
Looking grim....

But turned out ok....

Gasket face too...


now i've looked at that pic again, do you think that is was leaking?

Enough of all this, time to go to a friends house in Bridgnorth to look at everyone's firework display from the panoramic view

Graham.

 

Andy has a little trick for the TD 20g so the plan (today) is to send the 20g to him and do the d/pipe.

Graham can you enlighten me to the little trick re:20g.

 

Perhaps, but then he'd need to kill you

 

As you can see, the Wizzard is watching!
It will smooth the boost delivery and spead it a little 'wider'.
The car has always struggled to hold 1.4 beyond about 5500/6000 and the tweek is to keep it up for a bit longer (!)

I am hoping that the tweek will offset the cat and optimax without NF(maybe)

Graham.

 

Wow, what an awesome thread. Just read it from start to finish. Graham you are an inspiration
As for Andy's mapping, awesome, he did my RB5 last year.
I now have a new project and reading through this thread has given some answers that I have long been looking for. So thanks Graham for all you hard work that benifits the rest of us. I guess that's the nature of SN though.
I have a Modded UK turbo 2000 .
STI 9 crank, steel rods(eagle) , wrc bearings with RCM's oil feed modification but I stayed with the STI forged pistons, same headers as yourself , group A decat down pipe and decat centre with TSL's firestorm back box. STI version 5 heads Still running standard injectors and intercooler although i do have the walbro fuel pump with a VF 28 and still running andy's ECUTEK map. As for the transmission I mashed two five speeds in a month and went for the 6 speed, best thing i have ever done. So the foundation for what i really want is there. I already have the Apexi Power FC and commander sitting in a drawer (god bless ebay for that). Next on my list is a GT35 Garrett / IHI hyrbrid that RCMS do with ported shroud and P20 Housing, APS front mount, 740cc injectors, parallel fueling with SX reg( I know how to do it now) and then get Andy to come and map it all for the power FC.
So will hopefully see some good results from that little lot. I am currently running 331bhp and 300ft/lbs torque according to the dyno at Scoobyclinic a couple of weeks ago. I am told thats pretty good considering the turbo, intercooler and injectors that I am running(440's). I am looking for circa 450 as my end goal. Here's a couple of pics of the car at the mo you'll notice its the proper colour too
http://freespace.virgin.net/darren.davies/scooby.jpg

http://freespace.virgin.net/darren.davies/enginebay.jpg

I would say go for the six speed easy to fit and they are bullet proof. Get someone to help you though. I did mine on my own and it was a hell of a struggle on my diveway in the rain with only axle stands.

Good luck with next season and many thanks for a good read and some excellent tips

Darren