Let me be more precise.

Kumho V70 soft compound, about as close to 'road legal slicks' as you can buy.
205 16 45's so smaller rolling dia than the stock Impreza v3. (580mm iirc = Kumho)
33 psi all round
Track is bone dry, covered in all the other various competitor's rubber too.

Sti Trans, bog stock so whatever diffs are in there it is as it left Japan (4.44's)
AP organic clutch.(no smells etc on launch)

Ready for the start:
Track lights on Green = hill is yours
Car resting on a starter's block to hold the car in the light beams
Blip the throttle 3 time to get ready or so
At 4500 instant hold for a second or 3 and dump the clutch
Get some wheelspin (usually off the front)
The car lurches forward (does not bog down) and scream to 7500 and ****** 2nd (using the clutch) and off we go. The 64 ft time includes the gear change.

As to using 6000: It seems to make little difference TBH as I've tried it David; it might cut 0.05 off and stresses the car more (and me) so not worth it.

At Shelsley I tried spinning the tyres very hard in the pre-start area which i normally avoid to save the trans a bit, but didn't make much difference.

The car has no traction control/anti lag, I have to rely on my senses just as my competitors in the class do.

I did have a really cr@p week at work so 'mentally' not 100%.
I think I'm a cr@p hill climber trying to better things by better equipment

It is Loton Park in Shrewsbury next weekend, so will try a few other thing on the car, ie softer damper rates and maybe pressures too.

Graham (or at least trying to smile)

ps: appreciate the input, it is very helpful.

 

I was under the impression that wheelspin wasn't a good thing for a quick launch. Have ideas changed in recent years?

 

I need wheelspin to prevent bogging

 

Graham, what you doing on the 3rd July?

There is a RWYB at Elvington, it would be a good place to practice your 60fts, and compare to your 64ft time?

I calculate (could be wrong) that it would take 0.006 seconds to do 4 feet at 50mph

 

There is wheel spin and wheel slip (if you like)
It is more of the latter than boy racer wheelspin; I think this where you are coming from Jerry.
I think I'm racing at Shelsley again on that date! (awaiting entry confirmation)

That extra 4 feet in 60 seems nothing, but as a measure the EVO did 2.04/ Nissan 2.25/ Sti 2.1 (and I've done 2.05's before this year) so I'm in the hunt.
I think these times are a 'hill climb thing' based on the surface and inclination.

Graham.

 

Graham,

I don't want this to come out sounding the wrong way, but I did warn you against the 20g for your paticulat application, did I not? For the power that you have got from it, I think you may be better with the 18g, especially when you have the uprated gearbox as you can run more boost low down with the 18g and make some serious torque in the midrange.

As for the not holding boost, I have found it a problem with the 20g on some setups, especially those with open neck downpipes. I would recommend trying a helper spring on the actuator, or perhaps welding in a splitter into the turbo housing or exhaust, nothing major though.

A 2 stage limiter triggered by a clutch switch is certainlly useful, it takes the hassle out of monitoring the tacho and adjusting the throttle. It also has the added bonus of generating a little boost off the line, maybe just 7psi or so, but it means that you can lower the launch rpm without bogging so easily. You would really need to be thinking about a better clutch and box though to do this.

However I would say that the 60ft times from a drag strip will not translate to the hill, because of the way the lights are triggered. A set of drag lights uses a pair of beams, both of which are broken by the front wheel as it edges towards the line. The thing is, the clock starts when the front beam is made, so the wheel has to travel about 8-10 inches before this happens, so you get in effect an 8-10 inch head start, known as the "roll out". Since the car is starting fro zero speed this can take a little while, maybe 0.15 seconds, and 4 feet I make closer to 0.05sec (sorry Steven ) so I think that 2 seconds flat for 64feet isn't as bad as perhaps you're thinking. But with your tyres I think 1.8 64 ft times on the hill should be acheivable.

Cheers

Paul

 

You did warn me Paul!
All in all the car is good, but needs more punch in the mid range. Maybe then the 18g could be just right.
Can't mess about now mid season so will need to press-on.

I have never ever seen any saloon car (or sports car) on road legal tyres go below 1.95 secs for the 64 feet.

I think Xmas will see the box sorted and a Lateral paddle with sprung centre, maybe another shot at the turbo will be timely then.
I have already added more tension to the actuator by back spacing the cylinder a full 6mm so there is a good pressure on the waste gate flap. My D/P is not fully open, actually an old Magnex design.

Thanks for all the info, much appreciated

Graham.

 

Should be in the 11s with 400+bhp.

Any more thought on the i/c fans Graham?

 

I would be interested in having a go. What do I need to do to compete?

Cage? Full or is 4 point rear only cage enough? And I suppose harnesses, a beam breaker and some numbers.

Paul

 

Paul, this year you could just about get away with a 4 point; next year it is a 6 point mandatory.
MSA license, National B Speed minimum.
To enter with a Nat B license 9the best you can get if you are a first-timer) limits the event you can enter, but there are several one day 'B' events. My Club has it's own professional hill climb in Shrewsbury, and there are 'B' events at Harewood very close to Elvington.
Finally, you will have to join a recognised Motor Club, you have no choice.

Thus the costs rise to have a go!
It is all in the Blue Book.

Bob:

I have looked at the fan side and want to get more tech info. Nobody quotes CFM ratings for 7 or 8 inch fans, but if this is not forthcoming then it will be a case of scrapyard hunting (if you can find one around here nowadays) for something suitable.
Shallowest fan I've seen is 55mm thick so I have the room to fit 2 x 7'' fans under the scoop.
Will keep you posted as to progress.
Not sure if TMIC temperatures are by biggest prob with all this turbo stuff about!

Graham.

 

Paul, maybe you could give this a go?

 

Is the roll out distance in hill climbing similar to drag strips? A shorter roll out will easily cost a couple of tenths.

 

There's an invite to Scooby drivers for the Lotus club sprint series on SIDC here.

http://bbs.sidc.co.uk/messageview.cf...threadid=38856

Venue is North Weald Essex. Looks a cheap way to have a go. Was very tempted but I'm away that week. No hill or trees just a wide airstrip with cones. There's some video links with in-car footage from the previous event held there. It could answer a few of the questions of how sprint/hill climb starts differ to 1/4 mile starts.

Gerry

 

Gerry: That looks like good fun. V tempted

 

Actually, looking at the dates, I'm back on the 8th after a week working in Scotland. If I pulled my finger out on Saturday, I could make it.

 

what are the dates?

 

10th of July...as shown in the link I posted earlier from Pistonheads

 

On hill climb starts there is no distance to roll out.
As soon as the car moves the time starts.
Graham.

 

That will certainly make the 60ft times a lot slower than at a drag strip with up to 15 inches of roll out.

 

I will be doing that North Weald event, good practice and setup for TOTB as the surface is nigh identical to elvington.

Butjust realised that weekend was my potential trip to the 'Ring.

Paul

 

Wasnt aware that there was so much staging flexibility?

Paul: May well see you at North Weald

 

maybe so, but It depends on a lot of things, such as traction, weight, gear ratio's and how you launch the car.. With my inconsistent launches, road legal slicks, appauling geometry and running less power than on the rr my car varies between low 11's and low 12's.

David

 

Also.. Id look at running a CO2 intercooler spray if it were me

 

11s is what I would want from mine if it had 400bhp+ considering its already 12.2s on a UK car with a TD05-16g.

Agreed with traction, it can make a massive difference. Am yet to try an airfield surface but have experienced vast differences on a drag strip from it being v sticky (bad), to just right.

Bob

 

to get more power, (if your thinking power = quicker) which isnt necessarily true..

this may then mean new turbo.. this could then mean more lag.

More grip can mean you dont even make the 1/4 or can just bog down too much..

I dont know why but once you get the times to around 11secs it seems to get harder to make improvements..

Im sure paul will explain what I mean..

David

 

Got my mind set now on changing the turbo.(at Xmas)
What would the 18g give in torque/spool/power against the 20g?

Racing this weekend where the launches are good, ie I can pull 2.05 secs for the 64 feet (my 911 does 2.11 on road tyres and 230 x 230 engine....)

More power is definitly not = to better times.
More drivability (= torque?) is the answer.

Graham.

 

i would be blipping the throttle on the start line instead of holding it myself

try it, you might like it

 

I've tried that.
Sometimes it IS better if you blip, blip, blip and then drop the clutch almost as the engine is dieing, so using the mass of the flywheel to get going, and then full throttle...
Will let you all know how things go.

Graham.

 

Try concentrating too

F

 

If you follow the links to the vids from here:

http://bbs.22b.com/cgi-bin/ultimateb...c;f=1;t=003205

there's in car footage on the Dyney runs. I was pleasantly surprised to see that a throttle blipping technique was used rather than the brutal sounding hold at x revs & just drop clutch.

Gerry