Special getting closer...

911hillclimber · Post by **911hillclimber** » Wed Jun 29, 2011 7:43 pm

I concur about Richard, ace guy.

Oddly, someone else i know who has a good engine 'ear' has just called to say if I knew the engine didn't sound too good!

His take was that it ran much better at the start of the season this year, but from low revs to about mid range the engine sounded good and strong. mid to max rpm sounded very 5 or 6 cylinder, but not a miss-fire. This guy maintains cars for 50 years so knows his engines.

He said it sounded much better late last year when the carbs were 'out, the engine knackered and the gearbox with a mind of it's own....

I'm looking for a stout rope and a tall tree now.

911hillclimber · Post by **911hillclimber** » Thu Jun 30, 2011 5:25 pm

Spoke to Bob today about this plight.
He made some good suggestions to try first before the jets go in.
I'll give them a go before surgery begins...

If this goes belly up could always fit another (non Porsche) engine, ie 2 litre Impreza Turbo, 260 bhp in stock turbo form with a stout gearbox too!

gridgway · Post by **gridgway** » Thu Jun 30, 2011 7:52 pm

I know I said it before, but I'd want to be able to quantify the results of any changes. I think that people's "ears" are very poor indicators of power outputs, even if they do have millions of years of experience.

So to get the engine "fixed", get it on the RR and show the problem, then make changes to eradicate it. You can simulate the throttle opening and closing and the running characteristics of the hill.

I also suspect that you have unknown handling performance. If the car neither understeers nor oversteers, then you aren't going round the corners quick enough to test its limits of handling.

Maybe I'm way off (and tell me to sod off if I am), but I think that you need to find the problems then fix them rather than hurling isolated solutions at the problem!

I'll sod off now

Graham

jwhillracer · Post by **jwhillracer** » Thu Jun 30, 2011 10:41 pm

Hi Graham!

I think other Graham has it right. Have you been back to Bob and put the car back on the same rolling road to see what is happening, rather than surmising about it? You need to have hard facts rather than theories! There's no way that a car with more power, half the weight, and what ought to be better handling can be slower off the line, unless you've got no traction, which doesn't seem to be the case.

Don't go to too many different people about it - they all work slightly differently, and you lose track of what you have done.

Have you had Sean drive it at Curborough yet? Because a sports libre is such a different animal, you need to have someone in the seat who has driven one before, and knows what it ought to be able to do.

And you need a few more sunny dry days with your bum in the seat!

Cheers!

JW

PS - Once again - you know you can tell me to pi55 off as well!!

911hillclimber · Post by **911hillclimber** » Thu Jun 30, 2011 10:45 pm

No! It is all helpful.

The handling side is being addressed right now.
The chassis is going to be hammered out real time on track to sort the roll and the damping.
It tracks well, stable under braking (not that you do much of that on a hill) but most importantly, i can hammer it and find the grip.

The engine delivery is another factor. This was discussed with Bob.

The way is has been heard is how it feels inside the car underway.
The telling sign is at Prescott where there is a speed trap about 1/10 mile straight along (first 3 gears). (Almost a drag race)

911 (3.2 stock engine) = 65 mph 210 bhp/ton
Lola = 67 mph 440 bhp/ton
Impreza = 76 mph 290 bhp/ton

Now, that does indicate an issue with the Lola, and not the chassis

More:

The first 64 feet marker for standing start performance:

911 road tyres 2.12 sec for 64 feet typically
Lola, 12" wide slicks, 2.11 secs
Impreza, slicks and 4 x 4 = 1.8 secs

jwhillracer · Post by **jwhillracer** » Thu Jun 30, 2011 11:02 pm

Just looked up the Prescott results.

Methinks you're beating yourself up unnecessarily -

Peter Turnbull - 400 bhp GT3 lightweight on slicks - 47.70
Bob Mortimer - 2.7RS Replica very light on slicks - 49.02
Mad Mick Harriman - Audi Quattro 600bhp or more on slicks - 46.45
Young Loakes - getting to know his new steed - 48.13

Looks like a good day at the office to me.

And it came back in one piece

JW

PS - just looked up -

JW's best time at Prescott - 47.25 - 05.05.2002
JW's most recent time - 48.23 - 02.05.2004

with 25 years of wear in that driver's seat!!

911hillclimber · Post by **911hillclimber** » Fri Jul 01, 2011 6:16 am

Much appreciated Jonathan.

Sean will be at Curb with the car. He set it up and has raced for 3 years Nick thompson's B6 and Merlyn sports racer which he preps too.
One of the reasons i took the car to him for alignment.

I've invited him to bring overalls and helmet.

I have tweeked the engine as Bob said so it will be interesting to see if it helps cure the 'lifeless' feeling in the car.

Terry Clifford ran his Millington engined MP 43 (Ex Fidoe Sports Racer) to 44 at last prescott. He is very experienced with a lot of time in fast hillclimb cars, but a 44 nevertheless. The package is about 10 years younger and far more potent and built for hillclimbs from the outset.

I had hoped for a far better time from this car/engine, I have gone nearly as quick in my little 911 road car. Bet I could equal the Lola if the 911 was on slicks, but i have spent a long time in the seat of that car!

Doing a clubby B meeting at Loton next weekend, so will be able to evaluate any changes we make next week at Curb.

911hillclimber · Post by **911hillclimber** » Tue Jul 05, 2011 7:34 pm

Went to Curborough sprint track this morning with Sean from McClurg Motorsport who has set-up the chassis this and last year. Sean is an ex hillclimber and bought his overalls and helmet!
Good dry morning, so a good start. I ran the car round the very tight track to warm things through having set the tyre pressures and dampers/ARB's all to max soft.
Certainly is soft. Sean took it round after and came back with much the same feeling. This is the first time i've ever seen the car out and about. Sounds good! Looks strange without the body on though.

We went through a steady iterative process of changing one thing at a time, measuring the tyre temps starting with the front end. The adjustments made a noticeable difference to the way the chassis flowed, and then after the rear was similarly tweeksed Sean encouraged me to drive it much harder....

The chassis certainly flows now, and changed direction so well with no twitchy antics. Further, i had the opportunity to really try the brakes out andI'm amazed just how strong they are, 90 to 10 in about 3 seconds with the odd chirp from the front, no locking up. Pleased about that as I've never hit them hard unlike my Impreza or 911!

The tyre temps were good and even across the width so the set-up seems to be spot on, and it feels it too.

I have to admit it took a bit to pace it along, but to the end of the 2 hours i felt i was there, the car asking for a little correction as it changed quickly from left to right, done by letting the steering wheel slip freely through your hands , catching the wheel on slight opposite and nail the engine. Works in a 911, does too in the Lola. (no power steering, the Impreza was nowhere near this sensitive).

As to shere speed, well Sean concluded as i've done, this engine just is not cutting it. We agreed it feels like a chassis with 170 bhp, not 270.

The chassis is great, and I'm really pleased to 'park' the chassis now and focus on the engine.

Couldn't have done this without Sean, ace guy who knows what is going on mechanically and also in the driver's mind.

I feel very confident now with the package, so will leave the engine as is till winter and then;

Sell it?
Sort the engine (I thought i had!)
Change the engine in this chassis (and fit a Hewland)

Nige · Post by **Nige** » Tue Jul 05, 2011 8:36 pm

Good result from the chassis tweaks there, to be honest I always though 270 from what is a standard 3.2 to be err, mmmm generous!

911hillclimber · Post by **911hillclimber** » Tue Jul 05, 2011 10:17 pm

BUT, it feels like 170 bhp, hence the times are so similar to my 73T/3.2.
Sean is used to a Chevron B6 with a strong BMW 2 litre in it, so 650 Kg with about 240 bhp. He said it is nowhere as strong as the B6.

Will discuss with Bob and see where we go from here with the engine.

Bruce anderson's book shows strong bhp/torque on a 3.2 with webers etc so why mine will not do the same I don't know...
Maybe i simply need to inject it.
Plugs came out this afternoon, all 6 jet black and a bit sooty.

Sean was surprised how slow the 915 box is! At least I'm used to that.

gridgway · Post by **gridgway** » Tue Jul 05, 2011 10:38 pm

Looks like great progress. You should find some good extra time with the chassis changes and late braking confidence.

If you get to the bottom of the engine mystery, you will be much happier. Although quite why an engine that did a 270 on Bob's rollers should now only be feeling like a 170 is very odd.

Just a thought, have you looked at the ignition timing? The thing that brought my 2.7 MFI engine alive was changing the disti. Before that even though it did a 230 on Bob's rollers, it was dead as a dodo to drive.

Graham

911hillclimber · Post by **911hillclimber** » Wed Jul 06, 2011 6:38 am

The timing was set by Bob during the carb set-up, also this engine albeit on Weber 46's ran for 6 years in Terry Davisons Sports Racer but in endurance racing.

However! I think the dist is a T and I assume with T advance curve.
Maybe i should consider a Bosche 3.2 ECU driving just the ignition side.

An interesting line of thought! Thanks for the thought.

Dead as a Dodo to drive just about sums the engine up.

The chassis feels great now. The front slicks are all knarled and grained instead of looking new, and the rears much the same.

Felt like driving a single seater. Hard to stop looking at the front suspension moving about...

impmad2000 · Post by **impmad2000** » Wed Jul 06, 2011 7:28 am

What about a mapped ignition? Crankfire perhaps?
I'm using Ford EDIS with Megasquirt running the map (fuel and ign in my case, but can run ign only) or there's Clewitt too?
The EDIS kit can sit with no engine modifications, the dizzy can even remain in place.
Just an idea
Tim

Bruce M · Post by **Bruce M** » Wed Jul 06, 2011 10:31 am

Had a quick look and the T curve is very different to the 3.2

The T runs a lot more advance due to the lower compression ratio. Did Bob set the dissy slightly retarded to avoid pinking?

If you go with mapped ignition, a custom curve would be better. The stock 3.2 settings were typically a bit conservative (or use a chipped stock ecu).

BTW, how many miles were on the engine when Bob did the set up? Any time i've tuned a freshly built engine, the carbs needed redoing after 500 miles once the rings had fully bedded in.

911hillclimber · Post by **911hillclimber** » Wed Jul 06, 2011 12:57 pm

Very interesting.

I have a Bob Watson mapped Bosch ECU in my 911T/3.2 hotrod. I drove the 911 last sunday and it blasts along in comparison to the Lola engine. (stock 3.2 + 2.4 headers. That engine is 130K miles, never ever been apart)

The Lola 3.2 was re-ringed by me about 50 hillclimb miles ago. It was freshly done when Bob had it back for the rollers.

What 2.4 dist has a curve like the 3.2 map?? Best the E or S dist are rare, so...
It is easy to fit all the 3.2 sensors and the Bosch to the Lola with a 3.2 fixed dist assuming i can find the 3.2 parts. Keep the PMO's and the easy fule system, but add a mapped ecu.

An engine is given in the Bruce Anderson book of a stock 3.2 with '1/2' engine mangement and Weber 46's/SSI = 165 bhp.....

I know there is something fundamentally wrong here, and this is a very interesting fresh take on the issue. Will discuss with Bob on Friday.

Graham.