275 Radial whats the best and what size rim?

[XR8menace]

G'day all,

Didn't want to clog up Lee's aka "Dalts" 240NOT build thread with this topic so I thought I would start a thread since it seems this tyre choice is becoming pretty popular.

I've purchased a set of 275 ET Street Radial Pros to go on a set of 9.25 rims. I choose the 9.25' x 15' rims with a 6' BS primarily because I felt these would be the biggest I could fit under my BF XR8 ute with already pumped and rolled guards while still clearing the leaf springs.

15 x 10' rims with these tyres seem the most popular choice here and in the states. Although I've also read of blokes in the US running 12' rims with beadlocks on the 275 radials.

MT ET Street Pros seem to be the best ATM from what I have read. I have no experience with them yet....

Keen to hear other opinions out there!

Cheers Corey

[dalts]

Sounds like a 15x10 is the best going off paulie and dans advice,let me know when your back and ill pop over and have a squiz at the ute and try your wheels on!

Where did you buy your weld magnums?

Lee

[prasac]

the wheel and tyre package is only as good as the suspension package. the better you can set up the rear end the better everything will work together. slicks tend to be a more forgiving than a radial.

was talking to Khain with the purple Holden HR recently, he changed from the 3754R ET Street 275 to the 3754x x275 Radial Pro he 60'd a 1.25 on the weekend, best before with the ET Street tyres was a 1.30, though he did also change converters recently so that is another factor, car weighs 3600lbs and is on a 15x10 as well if i remember correctly. he loves them better than the ET Street.

me personally, can't compare between the 2 radial tyres, but, can compare between the radial and a slick. we run the radials on a 15x10 from what i have seen with other people, at high speeds in the deep end they tend to get a little squirrely on a 15x8 or 15x9, that would be even exaggerated worse on a 4000lbs car.


the Radial Pro is a little taller has a 89'' circ vs 87'' of the ET Street and has 9.8'' vs 9.5'' tread, plus with the more slick like grooving, the Yanks are 60'ing a 2-3/100ths quicker with the Pro. the Pro is also 1-2lbs lighter.

we run the ET Street 3754R on a 15x10, as it's more like a street tyre and because we drive on it to the track when racing etc. absolutely love the tyre, out of 50 passes we have only spun the tyres once out of the hole, the rest have been all clean passes, 60' a 1.300 on the radial, a 1.285 with a slick, however, when we run a slick the car is usually no exhaust/100lbs lighter, with the exhaust the best the car has ever 60'd with a slick is 1.32, so really the radial is showing a better result. the good thing is all this testing is done with the same fuel/tune. we have also got more runs out of the radial then a slick, around 40 passes the slick starts to go a little how you going, whereas the radial we have done 50 passes, 95% have been within the 1.30-1.34 60'. in the same trim with slicks but 50lbs lighter the car has run a best of 8.30@166mph, has run a 8.31@165 on a radial. though that slick time time is also 18 months before and the car was 50lbs lighter with slick, because of the lighter tyre/wheel and had a fibreglass bonnet.

we haven't even begun pushing the radial, i believe there is a 1.27 in it for sure, we leave the line on 5500rpm/12-13psi with a 10.5'' slick we leave at the same rpm but at 15-16psi, we could definitely leave the line alot harder with the radial, plus, the car being 100lbs heavier isn't helping

if you are driving the car i wouldn't hesitate saying go the ET Street 275, but, if you don't mind taking the wheels off at the track the 275 Radial Pro on a 15x10 it comes down to how badly you want to achieve the best time you can.

[dalts]

Well said paulie I will run et street for the reason of being able to drive to the track and run them at powercruise.

Lee

[prasac]

also i should mention we haven't done any suspension changes going from radial to slick, everything is still the same. for small cube cars making under 1500hp i personally believe if the rear end is setup right, there is nothing a slick can do that a radial can't

[prasac]

Originally Posted by dalts

Well said paulie I will run et street for the reason of being able to drive to the track and run them at powercruise.

Lee

that's the big thing with us also. for the 2-3/100ths the 3754x picks up, i dunno if it's worth the risk, ok, 5mins from the track go for it, but, i know at Sydney Dragway everytime we have went to the track around 4:30-5pm there is a Highway Patrol sitting at the roundabout

[XR8menace]

Originally Posted by dalts

Sounds like a 15x10 is the best going off paulie and dans advice,let me know when your back and ill pop over and have a squiz at the ute and try your wheels on!

Where did you buy your weld magnums?

Lee

Pm sent. Bought direct from weld racing.

[XR8menace]

Originally Posted by prasac

the wheel and tyre package is only as good as the suspension package. the better you can set up the rear end the better everything will work together. slicks tend to be a more forgiving than a radial.

That's exactly right Paulie! Once we get the engine/trans sorted and a few passes under our belt I will be booking into a guy my mates know of up here in Brisbane that is supposed to be a guru in setting up leaf spring cars for the track. I believe he did the suspension on another black turbo Capri with leaf springs here in Brisbane. Runs 7 or 8s from memory??

[prasac]

Originally Posted by XR8menace

That's exactly right Paulie! Once we get the engine/trans sorted and a few passes under our belt I will be booking into a guy my mates know of up here in Brisbane that is supposed to be a guru in setting up leaf spring cars for the track. I believe he did the suspension on another black turbo Capri with leaf springs here in Brisbane. Runs 7 or 8s from memory??

sweet as, probably the guy that did Stu Henry's.

the AFCO Nitrogen filled shocks are what all the super quick radial guys are running, they are the bee's knees but expensive, around $1250/pair


you don't have to spend alot of money, as funny as this sounds we had 15yo leaf springs and cheap as Pedders shocks in the rear end and 60'd a 1.30, that setup was the same as it was when NA


we now have Strange shock, no coils, same 15yo leaf springs in the back and went 1.285, the Strange are good as we can make adjustments and they are cheap enough $600/pair. we get compliments from some of the top chassis guys in the country about how straight the car is and how well it leaves the line.


only other change was to the front shocks, 90/10's are good and all when you are running 10's, but, when you start running quicker the 60/40's went in. it's harder to lift the tyre, we still need to put some chains or seat belt in to limit travel we haven't done that yet as been extremely happy apart from a couple of times it's wanted to go on the bumper

[XR8menace]

Here's a few pics of my new MT ET Street Radial Pros 275/60/15 on a 9.25rim.

[dalts]

Geez they are fat,how much room between the tyre and guard?

Lee

[XR8menace]

Originally Posted by dalts

Geez they are fat,how much room between the tyre and guard?

Lee

That angle doesn't show it but I reckon they will fit snuggly inside the guard when the rear end is squatting. My guards have been pumped 25mm and rolled.

A 10' rim with a 7' BS may have fit which would have bought the outside edge of tyre in a bit more from the guard.. but I didn't want to risk it when I had to order the rims from the states.

A quick look with the 6' BS is only leaving 1' and a bit gap between tyre and leaf spring.

Corey

[prasac]

looks good Corey, love those radials

Lee, the 275 3754R bag to bag measures about 12.5'', wouldn't say 100% accurate, if you can get your hands on some be best bet.

[dalts]

Thanks paulie going to pop over to Corey's and try his set on and go from there!

They look the business !!

Lee