AC Owners Club Forum
AC Owners Club Forum => Mk IV, Superblower, CRS and other Continuation Cars Forum => Topic started by: nashvet on February 14, 2012, 16:21:18
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I am new to this forum and have just recently purchased an 85 Mark IV. I hope that I do not offend the purists, but my plan is to vintage race this car. I will rmove most of the interrior trim and put it away for the time when it will be put back in street trim. i would really like to hear from anyone else that races their car, either in Europe or here in the US. What other modifications are typically helpful for handling purposes, etc. Any hepl would be appreciated.
John
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What events do you plan to enter? The Mk IV is not eligible for most US events as it is is neither "fish nor fowl" to most sanctioning bodies.
Still good luck and post some pictures!
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Actually, the MKIV is perfect for many US events. HSR and SVRA allow them as do big events like the KIC or HAWK.
What region of the country are you in ? I could suggest some events.
Can you put 15" wheels on the car and still clear the brakes ?
This would allow the use of Goodyear Blue Streaks which is sort of the common race tire.
Lots of fun to be had vintage racing...
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So will I see you at the Hawk with Brian Redman at Road America this year?
Gus
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Johan,
that is actually my plan. Not sure if I will do any events this season, but definately next, maybe in the fall. It really depends on how much I decide to do to the car. Will have to put in fuel cell and do some gutting of the interrior. I haven't taken delivery of the car yet, but that will probably happen in the next 30 days. I do plan to go to 15" wels if the brake calipers will clear. I use the Goodyear Blue Streaks on my csx4000 car and really like how they grip. Do yoou go to the Mitty at Road Atlanta? Do you by chance race a Lola?
Mac
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Hi John,
Welcome to the select band of Mk IV racers. Back in the late 80s and 90s we had several Mk IV Cobras racing in the AMOC Intermarque Series. The cars ran Hoosier Tyres on 15 and 16 inch rims. The quicker cars used a 302 Motorsport Block, bored and stroked to about 322 cubes (5.3 litres over here) and tuned tubular headers. Transmission was via a 4 speed top loader gearbox. They produced just over 500 real dyno horses and 420 lbs ft of torque. Strangely no one stripped the interiors, as the few pounds it would save made no difference at all. Brakes were AP 4 pot calipers on AP ventilated discs with Neverfade Pads. Springs were 50% stiffer and we fitted adjustable shocks to lower the ground clearance, and front and rear anti roll (sway) bars. Radiators were changed to aluminium and oil coolers made bigger. The windscreen was removed and a plastic fly screen fitted for driver only which gave you a huge advantage at the top end. You are right to get a fuel cell, but mount it as low as possible. If you are really serious and need any help, just ask. Andy.
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Thanks for your input Andy. I will probably do modifications required for safety and justm meet requirements for HSR and / or SVRA for starters. Then other things as they become evident. I will be glad to hear input from anyone's prior experiences.
Mac
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Hey Mac, yep, one and the same. Sounds like a fun deal to me. Let me know if I can help.
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quote:
Originally posted by shep
.... Brakes were AP 4 pot calipers on AP ventilated discs with Neverfade Pads... Andy.
Hi Andy,
Can you give us any guidance on which size AP calipers and disk should be used on a MKIV to fit within the 15-inch rims? Their 4-pot range of sizes are shown below, but with clearance within the 15-inch rims being quite critical I'm assuming that the disk diameter is the biggest deciding factor. I expect that there is no point keeping the disks originally fitted to the car.
Option/No Of Pistons/Suitable Disc Ø/Disc TH/Piston Sizes/Inlet Thread/Mtg Centres/Mtg Offset/Mtg Hole Ø/PL
Caliper 2 / 4 / 280-295 / 25.4 / 38.1 Ø / M10 x 1 / 130.0 / 43.2 / 10.2 / 53.0
Caliper 3 / 4 / 315-330 / 28.0 / 38.1 Ø / M10 x 1 / 152.0 / 44.1 / 12.2 / 57.8
Caliper 4 / 4 / 330-356 / 32.0 / 38.1 Ø / M10 x 1 / 180.0 / 42.0 / 12.15 / 57.74
Caliper 5 / 4 / 330-356 / 36.0 / 38.1 Ø / 3/8 UNF / 180.0 / 42.0 / 12.15 / 73.6
(Taken from Demon Tweeks website in case the text spacing above is difficult to read : http://www.demon-tweeks.co.uk/motorsport/brake-calipers/a-p-racing-pro-5000-plus-brake-calipers)
I'll shortly be making the switch to my cars brakes.
Thanks
Bruce
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Oh dear. The sizes above are from their Pro 5000 range. The sizes for their 'standard' racing brakes are shown below. Even more choices = even more confusing!
No. of Pistons/Option/Piston Ø (mm)/Disc Size (mm)/Disc Th. (mm)/Mount Type/Mtg Hole Ø (mm)/Mtg Offset (mm)/Mtg Centres (mm)
4 / Option 3 / 2x 28.6, 2x 34.9 / 330-355 / 28-32 / Radial / 12.15 / 44.1 / 152
4 / Option 4 / 2x 28.1, 2x 44.5 / 330-355 / 26 / Radial /12.1 / 42 / 180
4 / Option 5 / 2x 28.6, 2x 36.0 / 356 / 32 / Radial / 12.15 / 42 / 180
4 / Option 6 / 2x 28.6, 2x 36.0 / 356 / 32 / Radial / 12.15 / 62 / 130
4 / Option 7 / 2x 36.0, 2x 44.5 / 295-355 / 28-30 Radial / 12 / 44 / 152
4 / Option 8 / 2x 27.0, 2x 34.0 / 310 / 27 / Radial / 10.15 / 45 / 130
4 / Option 9 / 2x 28.6, 2x 36.0 / 356 / 32 / Radial / 12.15 / 40 / 210
4 / Option 10 / 2x 34.9, 2x 41.3 / 285-355 / 28 / Radial / 12.15 / 35 / 180
4 / Option 11 / 31.8 / 285-355 / 28 /Radial / 12.15 / 35 / 180
4 / Option 12 / 31.8 / 285-355 / 28 / Radial / 12.15 / 35 / 180
4 / Option 13 / 2x 27.0, 2x 34.0 / 300 / 28 / Radial / 10.15 / 35 / 180
4 / Option 14 / 2x 34.9, 2x 41.3 / 280 / 28 / Radial / 9.7 / 44.1 / 152
4 / Option 15 / 2x 34.9, 2x 41.3 / 280 / 11.5-25.4 / Radial / 10.2 / 22.0 - 30.0 / 152
4 / Option 16 / 2x 38.1, 2x 44.5 / 280 / 30 / Radial / 10.2 / 48 / 152
4 / Option 17 / 2x 34.9, 2x 41.3 / 278 / 16-17 / Radial / 10.2 / 40 / 120
4 / Option 18 / 2x 26.0, 2x 31.8 / 278 / 16-18 / Radial / 10.15 / 40 / 120
4 / Option 19 / 38.1 / 267-295 / 16-18 / Radial 10.2 / 37.25 / 130
4 / Option 20 / 31.8 / 267-295 / 16-18 / Radial 10.2 / 37.25 / 130
4 / Option 21 / 2x 38.1, 2x 44.5 / 295-356 / 32 / Radial / 12.1 / 42 / 180
4 / Option 22 / 2x 38.1, 2x 44.5 / 332 32 / Radial / 12.2 / 42 / 180
4 / Option 23 / 2x 38.1, 2x 44.5 / 332 32 / Radial / 12.15 / 42 / 180
Again, courtest of Demon Tweeks
http://www.demon-tweeks.co.uk/motorsport/brake-calipers/a-p-racing-brake-calipers
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Bruce.
Do you have 4 pot AP's fitted to your CRS? If so the dimensions of these (assuming their size is still produced) should just fit. I have them on my Superblower and apart from having to slightly shave the balance weights fitted to the inside of the 15" rims they fitted perfectly. If you don't have them on the CRS let me know and I'll get the ruler out.
If this size is no longer available would love to know the dimensions of the closest alternative in case I ever have to replace mine. From the photos on the Demon Tweeks site mine look like the Pro5000 ones rather than the 'standard' ones.
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Hi Bruce,
I was helping Graham today with some info on your old springs and shocks. I told him how beautifully it handled on those Avons you ran at Castle Combe. I was really impressed. Were they on 16" rims? Regarding AP 4 pots, the ones I had fitted to the Orange Mk 2 I used to race, came from a Metro 6R4 but with "bridged backs". I don't have a record of the part numbers, but I would suggest calling Bob Green at BG Developments, as he is most likely to be able to supply some which will fit inside the 15" rims. If that doesn't work, let me know, and I'll put down my Easter Egg and look some more. I'm at Donington this Sunday 8th April, racing David Emmans' Ace Bristol in the Fiscar 50s sportscar race with 4 other Aces! Should be a good race. Speak soon, Andy.
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Bob Green has retired. May I suggest you contact John Freeth at Performance Braking. Tel: 01600 713117 Email: JFreeth@PerformanceBraking.com
Malcolm
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Thanks Malcolm, and I thought it was just me who was getting older! Andy.
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quote:
Originally posted by SB7019
Do you have 4 pot AP's fitted to your CRS?
Hi Peter, my CRS did have 4 pots on it, but as it's moved on to a new owner I no longer have in downstairs to measure. If you could get under yours with a ruler that would be much appreciated!
Andy, thanks for your advice and yes, the CRS did handle very well, hence why I definitely need to upgrade the MKIV if I'm going to enjoy it as much! I was running on the 15-inch rims when we went around Castle Coombe - I found them to give a much improved handling over the original 16-inch wheels (although to be fair the Avon CR6ZZ tyres on the 15's were also vastly superior to the ageing rubber that was on the 16's when I bought the car. Big Al and Alec did a great job recommending teh uprated springs and setting up the overall suspension geometry. Once I've done the brakes and springs I'll most likely take it back to them to do the final setup. Good luck at Donnington - any chance you'll be able to get some in-car footage and post it on youtube for us to enjoy? I have a digital "HD Hero" camera with mount that you're welcome to borrow - I could always drop it off on Friday/Saturday if you're around.
Malcolm, thanks, I've just spoken to Johnathan at Performance Braking - John F will call me back on Wednesday next week when he's back from holiday.
Bruce
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Hi Bruce, From experience when I have fitted a video camera to the car in the past, something always seems to go wrong and you end up with 20 mins looking at the Armco! Let me get the first outing out of the way, and I'll maybe fit one before the next race. I have looked at those Hero cams, and they look perfect for all kinds of action sports. I may have to buy one myself! Have a great Easter. Andy.
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Just a quick word to say we had great fun at Donington Park, but unfortunately didn't bring home any pots! Qualifying was OK, although the engine didn't pull 100%, but I was 4th on the grid behind a Lotus Elise, an Aston DB2, and Robin Pearce in Tim's Ace Bristol. After the lunch break, when we tried starting the engine to warm up for the race, it was only running on 4 cylinders. The middle 2 had wet plugs, so David changed them which cured the problem. The start was good, but a Jag XK140 used its torque to come from 2 rows back, and take 2nd place. The new plugs made all the difference to our car, and I knocked 3 seconds off my qualifying lap time, and stuck with the leaders. I managed to pick off two cars, and was close on the heels of the XK140 who on lap 5 held second place. It was only going to be a matter of time, as our Ace was quicker through the corners and later on the brakes, which more than made up for the lower torque and power. Then about lap 6 there was a spit and a bang from the engine exiting a corner, but then it cleared on the straight. The next corner the same thing happened, and gradually it took longer and longer to clear, until I eventually had to retire. Robin Pearce was the first Ace home followed by Paul Conway and Tim Pearce (who also celebrated his birthday). At least in the results we won fastest lap in our class, which bodes well for the next outing at Brands on Mon 5th May. I know this is not strictly CRS or Superblower subject matter, but I thought you may like to hear how the weekend went.
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It has been a long time since I started this thread. However, currently I am at my second race weekend with my MK IV. My first event ( SVRA at Sebring Intl. Raceway) was also the first time I drove the car longer than a couple of miles test drive right after purchase. That weekend ended prematurely with a transmission failure during qualifying. This weekend is with HSR at Road Atlanta. So far so good! new trans. works well as do Goodyear tires on 15" FIA style wheels. Have also removed windscreen and replaced with race windscreen as well as removed carpet and seats. I added a vintage style competition seat and harness. Fuel Safe made a relica of the original tank in the factory location. Sway bars were fabricated front and rear which took care of severe body roll that was experienced at Sebring. I am having a great time although I am very much under power compared to the rest of my group. I am currently running the stock 302 with Holley Carb. The car seems to get a lot of positive attention!
John "Mac"
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Thats fantastic!
Keep us informed... and some pictures would be good!
Good luck.
:-)
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+1 regarding the pics... It would be great !
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I only have one picture from this past weekend's race with HSR at Road Atlanta in northeast Georgia. I had a great time even though It was my first race in the car. I went to Sebring at the end of Feb. but lost the transmission during qualifying and did not get to race. This week end car did great although with the stock 302 street engine I was out-horsepowered! I still won my class beating a 69 Z-28 Camaro and a small block corvette.
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can someone tell me how to post a photo???
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A previous thread thats worth a read.
:-)
http://www.acownersclub.co.uk/forum/topic.asp?TOPIC_ID=2560&SearchTerms=photo,posting
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Based on the link, do all photos have to be hosted on an online site to post?
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Hi John; no, photos cannot be hosted on this forum. As long as you can pick up the html code for an image, you can post it here with [img] before it, and [/img] after it.
(Using the 'reply to topic' button rather than 'quick reply' gives you a lot more options, such as the(http://www.acownersclub.co.uk/forum/icon_editor_image.gif) button puts the img bits into the post for you.)
E.g. [img]http://www.sportscardigest.com/wp-content/uploads/JMI_8330.jpg[/img]
gives you this:
(http://www.sportscardigest.com/wp-content/uploads/JMI_8330.jpg)
(Courtesy of the SportsCarDigest Tour Auto report (http://"http://www.sportscardigest.com/tour-auto-rally-2013-report-and-photos/"), please visit to view more of Julien Mahiels` great photos.)
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Here goes
(http://www5.snapfish.com/snapfish/thumbnailshare/AlbumID=8970151025/a=11906361025_11906361025/otsc=SHR/otsi=SALBlink/COBRAND_NAME=snapfish/)
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(http://[URL=http://s1335.photobucket.com/user/nashvetmc/media/photo_zps8c74b0d3.jpg.html][img]http://i1335.photobucket.com/albums/w675/nashvetmc/photo_zps8c74b0d3.jpg)[/URL][/img]
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sorry for the large size
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Looks good, fyi, Richard Sloop has several additional shots posted to the HSR page on Facebook.
John
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Lovin` the Red 'n' Gold! Good to see you ahead of the `Vette, too!
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Looks great.
Good start to your racing.
Must be nice to live in a country in which the sunshines!
[:)]
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[:)] Did stay in front of that Vette long (big block), but did pass and beat the small block vette in my class.
Actually had rained all night before and qualifying that morning was in the rain. The track dried nicely for the afternoon races though.
Next race will probably be Road America (Wisconsin) in late July. Hope to have more HP by then[:D]
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Nik.
Thanks for the link to the Tour Auto photos. Absolutely fantastic shots!