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11.875 @ 115 mph 1/4 mile = how much power ?

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Old 09 February 2002, 09:21 PM
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Pavlo
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Brake as in "at the water brake"

I guess it's correct really to refer to BHP at the flywheel, but I suppose it would be equally correct to say "PC Clone" rather than PC, which was a phrase coined by IBM.

On here, people generally state whether or not the power is at the wheels.

As for Mad4it, you are correct when you talk about injectors blah blah blah. But if you had been paying attention to all the other threads of Andy's where the spec is detailed, you would know for instance he uses an adjustable fuel pressure regulator to run stupidly high fuel pressure. He also has a 5th injector on the RA. And he's put in a 6th injector in the form of a nozzle that is opened via a pressure switch and solenoid to flow a further 130cc/min or so. You will have also seen a dyno sheet with 349hp at the flywheel, and one with 390 something.

Please tell me you are not lifting those times from the Elvington run? As that was over 500metres, a 1/4 mile is 402.23metres.

I guess Crail must use a shortened track to get the times then? Because the timeslip backs up the times.

Paul

look what I found....


[Edited by Pavlo - 9/2/2002 9:29:43 PM]
Old 09 February 2002, 11:04 PM
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Andy.F
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Afraid I've no idea mate, honestly, I don't know the turbo and it really depends on how it is mapped. Tell me the weight of the car and its 1/4 mile MPH and I'll get within 20 bhp

I agree that Santa Pod is THEE place if you are going to compare 1/4 mile runs. Bit like comparing one rolling road to another otherwise

Finally, about Crail....anyone quoting a Crail time from more than 18 months ago IS giving their mind a treat !! The current timing kit is pukka but the original kit had no staging beam !! this allowed you to line up a car length back from the timing beam and take a run at it This was deffo good for 1 - 2 seconds off your 1/4 time....maybe this is a contributing factor in your view of Crail ??

[Edited by Andy.F - 9/2/2002 11:10:43 PM]
Old 12 April 2002, 12:02 PM
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Cosie Convert
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Question

Can anyone tell me how much power it takes to run a 11.875 @ 115.38 MPH ¼ mile ?

The calculators I have used seem to be configured for Auto trans cars or 2wd cars running slicks.
As my car is a MY95 WRX RA they appear to give me unrealistic figures.

I have not had tbe car on a rolling road yet but hope to shortly.

My 60 foot time is 1.691 as I use standard street tyres, the car is in standard street trim.
The track is fairly new and a bit dusty at the start line

I have read that the close gears on the RA improve acceleration however I have also read that it is quicker to use only 4 gears on the ¼ mile as the additional gearshift on the RA will cost time ?

The time above was backed up with a 11.926 @ 115.09.mph The ambient temp was 60F
On the same day a MY02 was running a best of 14.75 @ 95 mph

Anyone had a car dyno'd that was close to these figures ?

Thanks

Andy
Old 12 April 2002, 12:58 PM
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David_Wallis
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could it be due to 2bar boost???

David
Old 12 April 2002, 01:39 PM
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Dan B
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How much does the car and driver weigh in Kg's? (hope thats not too personal, but needed info in Newtonian Mechanics )
Old 12 April 2002, 01:49 PM
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Adam M
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are these the figures you achieved?

if so, I would love to know the spec of your car as they must put you up with craig H as one of the fastest official scoobs.
Old 12 April 2002, 02:28 PM
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T-uk
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if you look in the scottish forum you will see a few threads about Crail and times from the last drag day.
Old 12 April 2002, 06:53 PM
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Cosie Convert
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Didn't want to say too much about the spec just yet as I'm still working on a few more ideas you probably wouldn't believe it anyway........it's not that special !!

Less than 1k spent !

The car weighs same as any other Ra I guess circa 1200 kg I'm 75 kilo, car was run with 1/2 tank fuel.

Old 12 April 2002, 10:24 PM
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ustolemyname??stevieturbo
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It is very difficult to estimate power from that, without knowing gearing and weight, ( driver skill ) The RA is a bit lighter than a normal subaru, with very short gearing, so could achieve better times than a similar powered loaded car. 14.75@95mph sounds pretty feeble. I hope it wasnt his best run!!!!
Also how was it timed, and the speed measured at the end of the run? I think a RA would struggle to hit 115mph in 4th, as the gearing is VERY short in these cars. Nevertheless, it is a very good time, and the speed does indicate that there could be a reasonable amount of power available. Your 60ft times should be good, its 4wd, If they were bad something would be very wrong. Even an idiot can get off the line well with 4wd, assuming the clutch holds up. I doubt that you could get a time like that with less than 300bhp, but im sure with gearing so short, it wouldnt take too much more. Top speed would maybe make me think it had more power, Most 4wd cars can get relatively good times, usually with lower terminal speeds due to their ability to get off the line better than their 2wd challengers.
Good run..
Old 12 April 2002, 10:48 PM
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R19KET
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"Good run"

That's a bit of an understatement !!! It's the fastest time ever ever "posted" on this bbs, and beats Harj's 12.77 by nearly a SECOND !!!!!!

Even in the US, where they're 1/4 mile crazy, no one has broken 12 seconds yet !!!! And all with less than a £1000 of mod's.

For what's basically a stock car, with a few tweeks, it's BLO*DY FANTASTIC.

WELL DONE......

Mark.
Old 13 April 2002, 12:48 AM
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Cosie Convert
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He he, as you know Mark I do have an uprated pump......but it's back in the garage !
I fitted it to richen up the top end, it done exactly as it said on the box 1bar more held pressure at high rpm, 9.5% CO.......and 25 bhp reduction

I tried reducing the pressure by a FSE valve but I was starting to run weak lower down (oh to have an adj ECU ) so I fitted the std pump again.

My fuel curve is a bit ragged as when my injectors are reaching 85% + at high rpm they switch to the held open position as there is inadequate time to close and open again. This gives me a 15 % step change in fuel supply. If I reduce my boost by a few psi I actually run weaker as I don't exceed the 85%(ish) step !

I run 26 psi in the mid range to ensure 100% idc from approx 4500 rpm (the torque available there is very impressive) ,as the volumetric efficiency starts to fall off and the turbo builds exhaust backpressure, the fuel demand remains fairly constant through to 6500 rpm.
I have experimented with the blend of methanol and water to achieve knock control and mixture trimming, I now have 3 jets in the intercooler !

My fuel system has been optimised to suit the std JDM WRX JECS timing curve which is not lacking in advance !!

Unconventional set up !!

Next step is chopping off the 90 degree inlet to the TD05 for a reduced pressure ratio across the compressor. Don't want more boost (yet) just reduced exhaust back pressure which will allow me to trim back on the %age water, add more methanol.....then maybe up the boost
Old 13 April 2002, 10:43 AM
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R19KET
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Andy,

Which FSE reg' are you using ? they do two, a 1:1rr, and a 1:1.7rr.
Be VERY careful. It sounds like the stock pump can't cope, pressure is dropping at high rpm, and that's why you're leaning out. The uprated pump was obviously able to maintain the fuel pressure, that's all it was doing.

You may be better off running the other pump, and reducing the water. Water has the effect of "richening" the mix, and when we run WI, we have to lean out the fueling, but you probably know this.

Can you try one of John B's gizmo's on the AFM, to lean out the mix ?

Mark.
Old 13 April 2002, 11:28 AM
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Cosie Convert
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Mark

You're absolutely correct, the standard pump is dropping pressure at high rpm. I have the 1:1.7 FSE but with hindsight, wish I had the 1:1 then I could probably run the uprated pump at a sensible pressure on boost whilst maintaining the appropriate fuel pressure for off boost throttle response.
As I've modified the fuel rails, fitting the oem regulator is not an option any more.

If i uses a Doc B trimmer on the MAF I may be able to keep the IDC below 85% and run higher fuel pressure to achieve the same flow, problem is, that may change my timing advance ? Also it is not adjustable for rpm sites. Unlike that tasty new Apex'i offering

Once I mod the turbo for more air flow I may just add yet another (4th) methanol/water mix injector for supplying the high boost fuel, after all they're only 6 quid each !!

Individual port injection ? mmmm .....one original petrol injector
with a methanol secondary injector ? could map this via an ERL system based on MAP signal, or even ask Doc B to design me a simple pulse width modulation circuit based on the original MAF signal......... I'm off to think !
Old 13 April 2002, 11:57 AM
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R19KET
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Andy,

Thought you may have the 1:1.7. Tried them, but I'm not keen. I've got a 1:1 you can try if you like.

Mark.

Old 13 April 2002, 07:14 PM
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Cosie Convert
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Thanks Mark, I wouldn't mind a look inside it for comparison purposes. I may be able to modify mine to be a 1:1 ratio ?

I think I'll explore this methanol enrichment a bit further, it really kills the charge temperature stone dead !! Which is handy, having a teeny top mount
Old 13 April 2002, 07:15 PM
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sanders
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Andy,
I was at crail on the 7th, is your car the white impreza with gold alloys that beat Dave Brown, if so it takes of from the starting line like a rocket, its a joy to watch keep it up.

Sandy
Old 13 April 2002, 07:27 PM
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Cosie Convert
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Cheers Sandy, twas I

I've got a set of grippier tyres for next time just hope I don't start breaking things !

Andy
Old 13 April 2002, 07:52 PM
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sanders
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Hi Andy,

That is one fast car you have, do you take passengers up the strip if so I would like a blast up the 1/4 mile strip with you.
I think I saw you at awd one time, do they do the work on your car if not who does do it because I could do with some advice on how to get my legacy turbo a bit faster.
Cheers,
Sandy

[Edited by sanders - 4/13/2002 7:52:52 PM]
Old 13 April 2002, 08:10 PM
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Cosie Convert
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Sandy

I do my own car. I used to build race cars and engines for others but now it's just a hobby

Dave at AWD has been looking after a number of Scoobys on this web site and from what I've read he does a good job at a competitive price.

Did you see their black 5 door on display on Sunday ? Very tidy
Old 16 April 2002, 09:05 AM
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CraigH
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Andy,

They are "quite" good times

At 1.5 bar my best time was 12.2@116 - so not too far out - if nearly .4 of a second isn't too far out.... and if it's cost you less than 1k you're a ****ing b4stard

At 1.5bar my car apparently was 360hp.

Can I just say that don't I believe the times or speed though as it's probably at Crail so please knock at least a second and 10mph off your times so as to preserve my godlike status (joke)
Old 16 April 2002, 09:36 AM
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David_Wallis
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Location: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
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are you planning on posting details on what you have done / intend doing, as I would be very interested in things such as removing the 90 degree inlet.. modified fuel rails... chargecoolers (if you ever made it.) etc..

As I would rather modify what I have or use parts off other cars..

Did you look into moving the throttle body to the front? as I seem to remember you saying that you couldnt just turn the inlet around..

Nice time.. (doesnt really matter what power your running with them times! )

David
Old 16 April 2002, 02:04 PM
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GavinP
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Andy,

I'm with David - how about some details about what you have done and the results - sounds like an interesting read!

Thanks

Gavin
Old 16 April 2002, 04:38 PM
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Cosie Convert
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LOL @ Craig H
Scottish miles are shorter in order to improve our MPG figures

Dave/Gavin I'm still "in the middle" of my modification programme Trying to see how much you can safely get out of the standard parts with a bit tweeking ! I've yet to remove the 90Deg inlet and fit the chargecooler (water jacketed STi intercooler) I'll keep you posted

Andy

[Edited by Cosie Convert - 4/16/2002 4:39:13 PM]
Old 16 April 2002, 04:55 PM
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T-uk
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I hope we will still see this car at K/hill on thursday night .

I am not sure if my finger will be ready after an argument with my knife last night ,well thats my excuse anyway .
Old 16 April 2002, 10:08 PM
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mlambert
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i wanna water jacketed STi intercooler!
Old 17 April 2002, 04:37 AM
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Cosie Convert
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Unhappy

Need to catch you (or try to) at the next round I'm afraid. Not going to risk that boost level on circuit until I get rid of that teensy intercooler.
Going to miss Crail as well this time due to 'ongoing' modifications
Old 17 April 2002, 11:46 AM
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T-uk
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turn the boost down then and come and have some fun,you would get bored if no-one could give you any sport because you were so much faster anyway .
unless like me,you are wondering if Dr Elassar has been away getting a 500bhp conversion so as to beat you
Old 17 April 2002, 08:15 PM
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Cosie Convert
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Talking

Who ? Sam ? He wouldni do that would he

Car's apart just now, going through another evolution
Old 17 April 2002, 09:07 PM
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teknopete
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Cool

Andy,

How goes m8, long time no c (stuff doin jnow)
Hope u r gettin ready 4 the MLR RR day bud, we gotta hold up the
Scooby name u know Do is a favour n mail me u r contact number
bud, need 2 c u bout some methanol n stuff. Recon the Cossies were non 2 chuffed a week past Sunday

BTW guys the timing system @ Crail has been replaced since last year, we now run the same porta tree system as u guys do at Pod
so that makes 4 real comparisons
There was word of some of u guys commin up 4 a North v South thang
at the summer hols @ Crail any u lads commin up ? I`m sure all us regulars will be there.

L8r
Pete

[Edited by teknopete - 4/17/2002 9:08:33 PM]
Old 19 April 2002, 12:35 AM
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Cosie Convert
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Pete, you have mail

ps You got a dented roof or door ????


Quick Reply: 11.875 @ 115 mph 1/4 mile = how much power ?



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