Mopar Muscle Association UK

Don't know how you get away with a tight converter. I know your engine will be making more torque than my little 440 but with a 2800 stall converter i was having to hold it on the brake all the time in traffic (and with manual brakes that is a pain) plus the 60 ft times were bad because the engine was not winding up enough off the line. The 3000+ stall i have now is much better to drive around town in traffic but still not ideal for the strip. You have to comprimise somewhere though.

I suppose using those very high rear gears takes half the torque away so maybe you don't have to hold it on the brake as much. The poor quarter mile times reflect all of this. With less power I am running high 11s.

My old Hughes cam makes peak torque at about 4000-4500rpm in my little 440. With the overdrive on that is.....a bit more than 70mph I can tell you! But it feels right at those speeds.

You do indeed get best milage at peak torque. In a vacuum. If your best rpm also means a high speed then wind resistance works against you. So although high speed driving is best for my car the best MPG is now a little less than peak torque now. Before it was not.

I was getting 13mpg before I fitted the overdrive with 3.91 gears. I now have the overdrive and 4.30 gears. The mileage has only gone up to 14mpg as a result but that is still not bad for a car this weight and speed in my book.

Hi Dave,
The reason for the high gears was that I used to run 3.91s, that with a 7260 rear uj it didnt hold up none to well (3 twisted and knackered)I`m on the hunt for an 8.75 mope or I may have to go 9" fraud. Until I find a stronger axle and a 7290 yoke I`m staying with the high gears and tight convertor, but its nice to be able to change down from 3rd+o/drive to 2nd+o/drive and pull up to some very very naughty speeds and have gears to spare . The car itself is set up for handling I have 1.160" torsion bars at the front with a 1.125" sway bar and at the rear the leaf springs are 6+ 1/2 each side with a 1.00" sway bar and lowered 2.00" all the way round with polygraphite bushes throughout,it handles quite well for a car that weights 1970kgs minus driver. Hey everyones different , thats what makes this board so good. Hope to meet up at the Nats

Regards
Dave Henry

Hey everyones different

Not that different! My suspension spec is close to that too. Great minds think alike etc.

I agree the tall rear gears are a good idea if the axle is weak. You must be making 500lbs of torque at the crank on that engine. Three times that at the wheels with those gears you are running. You could run mid 11s easy with the right converter and gears. 8)

Hi Dave and Dave.
I live in Markethill - a small village in County Armagh (approx 40 miles from Belfast) You're more than welcome to call for an evening's crack and a few beers when you're over this way - give me a call on 02837551935 when you're coming this way. I wouldn't mind seeing your motor and hearing the sound of 550+ horses. I'd even get to see the overdrive set-up in the flesh.

Just goes to show people now want these cars to do more than go in a straight line. I have done a similar set-up on the suspension - polyurethane bushings all around, 1.25" front swaybar, 7/8" rear, KYB gas adjust shocks all round , six leaf rear springs, and I added a home brewed rear strut tower and watts linkage (similar in operation to a panhard bar), lowered the car, and added 4 wheel custom disc brake set-up. It made an awsome improvement to the handling and now I feel confident going around corners.
Meant to ask where did you get the 1.16" torsion bars from and are they harsh - I was considering adding 1" sway bars but wondered whether they'd be too harsh for normal driving?

I am using 1" torsion front bars which is about a 30% increase over the stock 440/426 spring rate. Front sway bar is 1-1/8" and rear is 3/4" but I now wonder if I should have fitted a 7/8" bar and I will get around to fixing that this coming winter if I decide to do it after all these years. Rear leaf springs were custom made to my spec.

I say that but all I did was give them the dimensions and specified the camber and spring rate. I was lucky they had an old guy who could work out what thickness/length/number of leaves of steel to use to get what I wanted. Just deciding on the spring rate taking into account the weight bias on the car now was a huge amount of work for me as I kept changing my mind or getting different answers to the same equasions.

I did all this about 5 or 6 years ago? So it has been on the car for some time now and I am happy with it apart from wanting to increase the rear sway bar slightly. Maybe.
It does understeer very slightly when pushed VERY hard but of course it will oversteer if you give it too much throttle so maybe the balance is about right?

One thing I was planning for this winter was to add a Watts linkage set-up to my axle! Even though I have mounted the sway bar in such a way that it resists sideways movement I am still feeling the axle moving when I throw it onto a roundabout.

I have been trying to work out in my head how to exactly do this. Where to mount the center swivel bit and how to mount the end that has to fix to the chassis. I am trying to think of a way of doing it that does not look clumsy.

I would be VERY interested in seeing how you have gone about this. Any chance of a few photos?

Full spec of my car for anyone interested.

1970 Dodge Challenger R/T

List of Modifications

Engine Block

Original ?numbers matching? 440 cubic inch (7.2 L) HP2 Chrysler RB V8.

Bored 30 thou oversize. Keith Black quench dome 10:1 hypereutectic pistons.
Half inch Milodon oil pick-up. Modified windage tray. Stock sump with temp sender. JP Performance double roller timing chain and adjustable timing sprocket. March Performance serpentine ribbed belt type crank/alt/water pump pulleys.

Machine work and assembly of short block by Hauser Race Cars.

Camshaft

Hughes Engines Hydraulic HE3844BL

Valve lift (w/1.6:1 ratio) 0.571"/0.576"

Duration (@ 0.050? tappet lift) 238/244 degrees.
Duration (advertised) 287/291 degrees.

Race type hydraulic lifters.

Heads

Original type ?906? iron castings surface cut 10 thou. Ported at Hughes Engines to their Stage One spec. Stainless steel one piece valves 2.14? intake and 1.81? exhaust. Three angle valve seats with hardened inserts. Bronze wall valve stem guides. Adjustable aluminium roller tip rockers with 1.6:1 ratio and billet hold down clamps.

Induction

?Six Pack? 3x2bbl Holleys fed by a Carter 'Strip' mechanical fuel pump and Holley regulator. Carbs are mounted on an Edelbrock aluminium intake with the heat cross-over passage blocked off.
Centre carb has air horn & choke machined off (Ok I used an angle grinder!) and the venturies smoothed for better flow. The jet sizes are #66.
Outboard pair (secondaries) modified to accept accelerator pumps, squirters and progressive mechanical linkage. Both secondary metering plates are drilled to 98 thou.

Exhaust

Headman headers with 1 7/8 inch primaries into 3 inch collectors. Exhaust wrap. Home made 3 inch exhaust system with two Warlock mufflers and two 3 inch ?cherry bombs?. Oxygen sensor for air/fuel ratio monitoring on left bank only.


Ignition

Chrysler electronic distributor and Jacobs Electronics spark amplifier. Battery re-located to trunk.

Cooling

?Be-Cool? custom fit aluminium radiator. High output ?Flow Kooler? water pump. 180 degree thermostat modified for better flow. Trans and engine oil coolers. Summit Racing Electric fan.

Transmission

?Numbers matching? Torqueflite automatic mated with Gear Vendors overdrive unit. Trans rebuilt to street/strip spec with B&M Transkit. Fitted with 10" TCI ?Streetfighter? converter, deep oil pan, and temp sender. Hurst ?Pistol-Grip? type Quarter Stick shifter fitted into original centre console. Driveshaft safety loop.

Axle

Original 8.75 inch ?Sure-Grip? axle. Rebuilt with 4.30:1 gears. Effective rear ratio with overdrive engaged is 3.30:1.

Brakes

Original 11x2.5 inch drums on rear. 1976 Police car 11.75 inch discs fitted to front. Mopar Performance light-weight master cylinder. Power assist removed.
Electronic line-lock to front brakes operated from button on top of shifter.

Suspension

Up-rated about 30% all-round with custom made leaf springs at rear (each moved inboard by ? inch) and 1 inch diameter front torsion bars. Polygraphite suspension bushings.
Anti-roll bars are 1 1/8th inch front and ? inch rear. Gas shocks.

Steering

Manual steering box with 20:1 fast ratio gearing (4.5 turns lock-to-lock)

Wheels and Tyres

Custom width Chrysler Rallye wheels. 15x8 front. 15x10 rear.
B.F.Goodrich Radial T/As. 245/60 front. 295/50 rear.
Hoosier 28x10 inch slicks for rear when on Drag Strip.

Bodywork and Interior

As original except for;
Wheel lips cut. Plastic front bumper. Painted ?Hemi Orange?. Black vinyl top and black interior fitted. Chassis strengthened with chassis connectors. Auxiliary gauges fitted in dash for water, engine oil, and trans temp. Air/Fuel ratio, fuel pressure and volts. ?Monster? tach with remote shift light fitted above steering column. Headlights and turn signals to UK spec.

Performance

Best quarter mile time to date: 11.92
Best quarter mile speed to date: 113mph
Top speed: 145mph
Engine power at crank: 520hp (est.)

Sounds like you've spent a lot of time and money on that car. I didn't know you could even get serpentine drive systems for Mopars - thought they only catered for Cheebys and Frauds.
Depending on your front rear weight bias you may be able to go to a 7/8 sway bar but if you are only getting some understeer you may want to leave it like that. I will get the digital camera out and get the car up on axle stands ASAP for some photos of the Watts linkage - it's centre pivot is located centrally on the rear of the 8 3/4" housing. I must admit though that when throwing the car into a car I also get the sensation that the axle is moving relative to the car but I know that the Watts linkage is not moving. I have yet to take the car for a four wheel alignment, but I believe that it is down to the geometry of the leaf springs. I once read that the best set-up on a mopar was to have the front portion of the leaf spring sitting horizontal relative to the ground. As standard they point down to the front, but as the car leans into the corner the axle moves forward at one side and rearward at the other due to the arc of travel that either spring must follow around the front perch this I believe gives the uneasy feeling that the rear of the car is going to slide out. I made and fitted front perches with three hole positions for the spring. I have it in the mid position at present but the spring still points down. I plan to move it to the top location i.e lower the car and level the front portion of the spring very shortly - I will let you know my findings.

Hi Dave & Dave,
Fair play to you buddy, sounds like you`ve spent a lot on development of your car, The progressive linkage on the sixpack, is it your own ideas or is it like the "six pack to go" version? I`d be really interested to see that.
GTX Dave, thanks for the number, unfortunitly the car wont fit on the flybe planes so I`m afaid thats a no no. The torsion bar part # is P5249161 and I brought mine through Hauser`s a few years ago and if memory serves me right they where about ?170.oo. I used to run the 1" bar that I got from PST`s but found it still lacking firmness,wether that was because it was not a Mopar Performance part I dont know, whereas now the front end stays solidly square through corners, I set the front suspension with 3 degrees positive caster and 3/4(three quarters of one degree) degree negative camber and 3/32nds toe in thats on 235x60x15 tryes. not had a problem with the inside edge wearing either. Is this a new sport "throwing cars into cars" A must see I think.


Regards
Dave Henry

It is indeed the "Six Packs to Go" conversion. Poor Linda carried the carbs to and from the USA as hand luggage to get them done. Took a LOT of tuning over the last few years to get right but I think I have them just about pefect now.
Awesome throttle response considering the mass of my rotating assembly and not as thirsty as I thought they would be.

My front end is set to the same toe-in but with 1 full degree of negative camber (no uneven tyre wear either) and although I had as much caster as the stock upper bushes would allow I did have it reduced a bit because of how hard the steering is with the wide tyres and fast ratio manual steering and now I can't remember at all how it ended up!
I do remember Richard Ehrenberg telling me that 2 degrees was plenty enough.
Anyway. It steers OK considering what mopar steering is normally like.

I guess we have spent a lot of money on this car over the years. But I have owed it since 1989 and it is still worth more than I have spent. Maybe.
Linda Woodhead came on board as a 40% owner some years ago. Can't remember how many now. That was the main injction of cash that got this car finished and running this well. Never wanted it to run faster than this. But you cannot help tweaking every last horsepower out can you?

I wish someone would organise a Mopar handling event. Zooming around cones and such. I am not very competetive but I would like a chance to push the car PAST its limits so I can find where they are.

Passed through Northern Ireland and Belfast on a couple of occasions traveling with my dad during school holidays. The people were always very kind to me as I was only a little kid with sticky-out ears and a crew cut. I remember it well. The ladies in the transport cafes all seemed to want to feed me up and the other drivers were always giving me boiled sweets and toffees!
We stopped going though as a Brit lorry got set on fire in the car park along the road from were we were parked and sleeping in our truck. This was 1968 of course and things were getting a bit hairy there. My dad refused to take me any more and stopped going himself not long after.