Wanted 6" and 8" 13" Caterham wheel

[Croc]

Croc:

Why? And will you lose top speed? If so how much (not relevant at NJMP?)?

What size rear/front wheels did your car come with (15x9 and 15x7?)?

 

13 inch wheels are better for the seven generally - less unsprung weight, handling, etc. plus I was not happy being stuck with Avon CR500s given the Avon supply chain problems and financial issues. Originally I had fronts 7x15 shod with 195/45 and rears of 9x15 shod with CR500 5/40. I am going to 7x13 with ZZR 185/55 and 9x13 with ZZR 215/55. Avon UK has ok'ed the 215/55 going on the 9x13 rims and they have a good track record on CSRs in UK and Europe. Apparently the ZZRs will be ok up to 9.5inch wide rims. This ZZR solution does drop the diameter by 0.9 inch on the front and 0.4 inch on the rear. The rear rolling circumference is a reduction of 1.3 inches. Modelling shows I lose 3-4mph from Vmax so 138mph down to 134mph. Given my GPS logged fastest on any track has been 131 mph I dont think I will be too concerned about this. It has to be a really long straight to cause me Vmax problems - maybe VIR as it wont be at NJMP. Critically the new race hub solution does open up the way for slicks to be mounted on the CSR in the future. Worst case I have to change the final drive ratio from 3.62 to the standard UK CSR ratio of 3.45 or regular Caterham of 3.38. I will worry about that once my new getrag gets delivered. :leaving: I am keeping the 15 inch wheels and Avon CR500s as a road wheel/tire combo but Avon can also give me a 175/55/R13 or a 205/55/R13 or 245/50/R13 which do not change diamater or circumference for road purposes. Kumho and Yokohama also become brands that will be open to me. I will probably not get this all done in time for our June sevens event but thats ok as I have a few other "upgrades" that take priority.

Edited April 19, 2013 by Croc

[O Racer]

A bunch more questions...

 

What is the stock wheel offset for the early 90's Cats? I assume you should stay with this same offset as you upgrade to wider wheels.

 

Are there any issues with stock hubs when I add wider wheels and soft compound tires?

 

Seems like a lot of you guys have cars newer and further developed than mine, I want to make some improvements to lap time and safety but I think my goals might be more modest as my engine HP goal of even 175 is less than the stock Sevens that followed. I do not plan to change transmission or diff as I am happy where I am at speed wise will be happier a little faster but I don't mind getting past at track days by faster cars. After three years racing in Spec Miata I much more enjoy the simple pleasure of the track day experience

 

So, and that's a big so, as for wheels and tires

If I go 6x13 front and 8x13 rear now thinking of Hoosier A6 or R6 tires, is that enough wheel and tire for my intended build out?

 

Also, I am still running the stock exhaust I understand it will not fit with 8" wide rears so i will change to side exhaust. Any suggestions for a minimal muffler to meet 92 DB with my engine?

 

Thanks to all for your input

 

John

[Croc]

What is the stock wheel offset for the early 90's Cats? I assume you should stay with this same offset as you upgrade to wider wheels.

 

 

Not sure what the stock offset is for your specific car. As I recall they changed details like that as specifications changed over the years. You can measure your existing wheels if they are Caterham branded wheels?

 

I generally try to keep the offset static when changing wheels as that way you do not run into troubles with the wheels not fitting on the hub or inadvertently widening the track and creating new problems.

 

 

 

Are there any issues with stock hubs when I add wider wheels and soft compound tires?

 

Not if you are only going up an inch or two. I have seen people put 10 inch rims with sticky slicks on a Caterham and despite how ridiculous it looks there has been no hub failure. The hubs on our Caterhams were off some large sedan. While I am not sure what car your hubs would have originally come from, my rear hubs for example came from a 2000 year VW Passat - so the design strength of these is for a many thousand pounder car - it will handle your modestly increased loads.

 

 

 

 

Seems like a lot of you guys have cars newer and further developed than mine, I want to make some improvements to lap time and safety but I think my goals might be more modest as my engine HP goal of even 175 is less than the stock Sevens that followed. I do not plan to change transmission or diff as I am happy where I am at speed wise will be happier a little faster but I don't mind getting passed at track days by faster cars. After three years racing in Spec Miata I much more enjoy the simple pleasure of the track day experience.

 

Yes quite a few people around me have succumbed to "upgradeitus" on their Caterhams because they have a fat wallet and want enough power and torque to move an aircraft carrier or ride on magnesium wheels and 3 lap sticky slicks. By contrast, I have left my car 'stock' to show how modest I am. I have no problems being (one day) passed by someone with 320hp. As an ex-racer I totally agree with your philosophy of just enjoying the track day experience with a few buddies and the beers at the end of the day are full of laughs as we relive the experience.

 

 

So, and that's a big so, as for wheels and tires

If I go 6x13 front and 8x13 rear now thinking of Hoosier A6 or R6 tires, is that enough wheel and tire for my intended build out?

 

REfreshing my memory, you have a 1700 crossflow now...so say 95-100hp. You are thinking of going up to around 175hp. Caterham says that 8 inch wheels on a new 125hp Supersport is over-tired. But Blatchat says 8 inches is a good size once you get into higher horsepower. I would make the rears 8x13 now and accept that you will be over-tired and have trouble rotating the car on track until you get your power upgrade. I would also suggest that you think about 7x13 on the front - narrowing up the width gap between front and rear is preferable to my mind given your before/after hp range contemplated. I have only run slicks on pure race cars and not a seven as I don't think you need it with a seven which rewards an element of slide in how it handles a track, so I defer to someone else here.

[yellowss7]

 

I have seen people put 10 inch rims with sticky slicks on a Caterham and despite how ridiculous it looks. :toetap05::toetap05:

 

 

By contrast, I have left my car 'stock' to show how modest I am.:bs:

 

 

What a troll. :smash:

[S1Steve]

What a troll. :smash:

 

And the Bullshit meter just broke.....

[Croc]

And the Bullshit meter just broke.....

 

Some people are a little overly sensitive I guess :jester: I was not really thinking of him that much....:rofl:

[Kitcat]

ORacer-I suspect a hp bump from currrent 95 (approx) to 115-135 is fairly realistic for your X-Flow. Not so sure abt 175hp: that's more than my Duratec and Zetec w/much older technology and smaller displacement. Depends on how much $ you can commit and if you get waaay up there $-wise, why not just get a BDA?

[supersportsp]

ORacer-I suspect a hp bump from currrent 95 (approx) to 115-135 is fairly realistic for your X-Flow. Not so sure abt 175hp: that's more than my Duratec and Zetec w/much older technology and smaller displacement. Depends on how much $ you can commit and if you get waaay up there $-wise, why not just get a BDA?

 

I have to agree about what KitCat said in regards to getting that much power out of a X-flow. That is a lot of power to ask of a streetable motor.

 

I like the BDA idea though.

[O Racer]

Hi guys

 

I just went through the Factory build manual that came with my car which included engine specs

 

The 1700 AX block SS motors as follows:

 

HP. 135 at 6,000 RPMs

Torque 122 at 4,500 RPMs

Comp ratio. 9.75:1

 

Formula Ford kent engines getting 110 HP with downdraft Weber and mostly stock parts

 

I could be wrong but don't see how this engine could be putting out 95 HP

 

It's never been dynoed maybe should start there

 

John

[yellowss7]

I think Kitcat was quoting Hp at the rear wheel, vs you quoting at the flywheel.

 

Tom

[bball7754]

I'm not sure I'd put too much stock in the Caterham hp estimates. My Crossflow was originally the same spec as yours, and then was upgraded to the 150 hp spec by changing the cam to the Kent 244. I did a dyno day about 5 years ago, and I think I had 109 at the rear wheel.

 

I missed both a BDA and a BDG that Craig Chima was selling, so opted to go ahead and "refresh" my Crossflow. Curtis Farley, who is a fairly well known Formula Ford engine builder, is doing the work.

The only major component upgrades are forged pistons and SCCA SCAT crank. The crank should allow me to comfortably move my redline from 6500 to 7000. Already have double valve springs and roller rockers, but the valve springs are being replaced.

 

Some head work had been done, but Curtis said it was like they got 75% done and then stopped, so he's "cleaning up" the head. Valves are slightly larger and, in Curtis' words "kinda slick" - although he didn't give me any details as to why.

 

He thinks the compression ratio was below 9.5, but expects it to be slightly over 10 when he's done. No surprise here, but Curtis hasn't/won't make a prediction of hp. I'll be happy with a true 150 at the crank.

 

175? From what I've read on Blatchat, it's possible. But I think it's also expensive. For starters, a steel crank - which runs around $2-2.5k (the SCAT crank is less than half that).

Haven't given up on converting to a BDA at some point, but this will tide me over for a bit.

 

Steve

[O Racer]

Thanks guys for putting my HP numbers in perspective. I was always referring to crank HP and now seem to remember the local market might have gotten close to 135hp with higher octane fuel and that the US cars were detuned to close to 125hp. Has anyone heard that tale?

 

I am really happy with the HP I have now and whatever I do to increase it, even by 20 HP will make me even happier

 

Thanks for all the advise, would love to hear what other owners have done to bump up engines from stock

[Kitcat]

Ivey Engines in Portland, OR is an established, reputable X-flow rebuilder/upgrader.

[O Racer]

I know this is an old post, I was just revisiting it to see about tires for my 6" X 13" Panasport Comp wheels. Four plus years since the last comment. Does anyone have a suggestion for track day tires for this wheel set that will not be used on the road, I have a set of 6" x14" wheels for street use.

 

Also, my race engine was completed a year ago, almost and it was more than satisfactory. Here are the specs from an engine dyno

 

Caterham Race Engine 2016

 

Block: Ford OHV 2265E Kent AX Block

 

 

Bore: 84 mm Stroke: 77.62 mm

 

 

Capacity: 1721 cc

 

Compression

Ratio: 11.5:1

 

Maximum

Power: 160 HP at 7,200 RPMs

(At flywheel)

Maximum

Torque: 125 ft/lbs at 5,600 RPM’s

 

Ignition Timing: 12 degrees B.T.D.C. at 1,200 RPMs

 

OR 34 degrees B.T.D.C. at 4,000 RPM's

 

Valve Clearance (Hot): .018” / .018” ( I / E )

 

Valve Clearance (Cold): .018” / .020” ( I / E )

 

Spark Plug Type: NGK BKR7E

 

Spark Plug Gap: .030"

 

Firing Order: 1-2-4-3

 

Fuel: 110 Octane (Shell Purple)

 

Oil Type/Viscosity: Redline 40 wt Racing (10W-40)

 

Oil Filter: MOBIL 1 (Part No. M1-301)

 

Cylinder

Head: Gas Flowed with Enlarged Ports

 

Valves: Ivey, Oversize (Intake: 41mm, Exhaust: 35mm)

 

Valve

Springs: Ferrea (S10115) Heavy Duty, Duplex with

Burton Hardened Retainers

 

Camshaft: Kent A6

 

Rockers: Burton High Lift Roller Rockers (1.69-1)

 

Pistons: CP Carillo Forged 84mm bore 11.5:1 CR

 

Flywheel: Stock Lightened to 12lbs. and balanced

 

Con Rods: Stock Ford lightened and

Balanced 600 g (with bolt)

ARP Bolts

 

Crankshaft: SCAT SCCA Crankshaft

 

Clutch: Helix Cover

Helix 3 paddle clutch plate

Throw Out bearing (Burton)

 

Ignition: Distributor: Pertronix Flame Thrower

Coil: Pertronix Flame Thrower II

 

Valve Cover: Caterham Cast Alloy with

1700 Supersprint Script

 

Lubrication: Titan 5 port Dry Sump Pump

Six Quart Alloy Oil Tank

Alloy Dry Sump Pan

Remote Oil Filter Housing

MOBIL 1 Oil Filter

 

Intake

Manifold Caterham Cast Alloy

Matched to head and carbs

 

Carburation: Twin Weber 45mm DCOE

 

Air Filters: Weber three screen filters

 

Header: Caterham Competition 4-1

Collector 2” Outlet

Stainless Steel

 

Muffler: Magnaflow

 

[O Racer]

To conclude this thread, I did find 4 Panasport Competition 6" x 13" wheels

[inchoate]

To conclude this thread, I did find 4 Panasport Competition 6" x 13" wheels

 

Interestingly I find myself in need of a set of 13" wheels. Where did you get your Panasports?

[O Racer]

inchoate A friend with a Seven knew of 12 slightly used 6" X 13" Lightweight Panasports for sale. He also knew of another Seven owner, so we bought and shared them. When I tried to buy them new 4 years ago they were not aviailable. I believe the distributor in the US is in LA. Check the Panasport site

[inchoate]

inchoate A friend with a Seven knew of 12 slightly used 6" X 13" Lightweight Panasports for sale. He also knew of another Seven owner, so we bought and shared them. When I tried to buy them new 4 years ago they were not aviailable. I believe the distributor in the US is in LA. Check the Panasport site

 

interesting. there's no desperate need as these would be track wheels. i'll keep my ear to the ground and something will come along.

[FE07]

Inchoate,

I've got a set of 6" (maybe7"??) x 13" wheels. They've always been track wheels that I got when I bought my car. Have old rains on them now which are beat.

Just sitting in my garage. If you're close to Philly, may work well as I'm outside of Baltimore and don't really want to ship. Give me your email and I can try to send you some pics if you're interested.

 

Jim

[Slonie]

To bump an old thread, because my question is in-line with some of the information in here already:

 

I'm trying to decide on new tires for my Caterham (Zetec, 200hp?), which came with 13x6 front, 13x8 rear wheels, shod with Kumho V700 215/50-13 front and 235/45-13 rear.

 

Now, whether or not that's too much tire for the car is not my question here... These tires are old and I'd like to replace them (I think they were the "as-new" tires on the car when the build was completed in 2002).

 

Now, the way I see it I've got two easy options:

 

1) Avon ZZR or ZZS in the Caterham OEM spec sizes of 185/55-13 and 215/55-13

2) Toyo R888 or R888R in 185/60-13 and 205/60-13

 

Now, the Toyos are cheaper and can be mail-ordered, and are apparently very good tires.

 

While the Avons (ZZS, anyhow) are probably better in the wet (relevant, although I'll usually only be drive in good weather), and may come up to temperature faster (relevant, since I drive on the street). The car will be used primarily for street driving. Autocrossing or track in the future? It's possible, but it's not my primary concern.

 

One more data point: It seems that the Avons will be about $864 for a set from a local distributor. The Toyos could be landed for about $557. That's a big difference, but since they'll probably be on my car for quite some time*, I'm interested to hear whether it would be worth it to spring for the Avons.

 

I'd welcome anybody's opinions on these two tires, or maybe another option I've missed**. Thanks in advance!

 

*although probably not as long as the Kumhos have been on it, prior to my ownership!

**I used to run 15" wheels on my AE86, the selection is downright bountiful in comparison to 13"!