Omega Owners Forum
Chat Area => General Car Chat => Topic started by: Big_Al on 23 May 2011, 17:10:41
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hi guys & gals
I have been looking at some new 17" alloys for the Omega. Want to fit new tyres as well & was discussing thois with a local alloy wheel/tyre supplier.
I mentioned that my opinion of 235 45 17 tyres on 17" rims on the Omega makes the wheelarch/tyre gap seem a bit excessive.
The tyre guy suggested that 235 50 17,s would look better.
He seemed to think that it would decrease this gap by 10 - 12mm & make the car look like it is sitting slightly lower.
He also mentioned that the speedo reading would be slightly incorrect but by a minimal amount.
Any thoughts on this idea. :y
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not sure tech 2 can arrange on that size but his suggestion is logical imo.. if your roads are not perfect those tires will protect your wheels and will be more comfy.. but 235 width will make the steering stiffer and increase the fuel consumption as you can guess..
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not sure tech 2 can arrange on that size but his suggestion is logical imo.. if your roads are not perfect those tires will protect your wheels and will be more comfy.. but 235 width will make the steering stiffer and increase the fuel consumption as you can guess..
width
I'm sure that 235 tyre width is factory fitted on facelift Elites as mine is. 235 x 45 x 17
Might be wrong though :-[ :-[ :-[
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not sure tech 2 can arrange on that size but his suggestion is logical imo.. if your roads are not perfect those tires will protect your wheels and will be more comfy.. but 235 width will make the steering stiffer and increase the fuel consumption as you can guess..
width
I'm sure that 235 tyre width is factory fitted on facelift Elites as mine is. 235 x 45 x 17
Might be wrong though :-[ :-[ :-[
It is AFAIK (ditto on mine)
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I dont care what factories fit ;D
I use 215 55 16.. good price even in good brands .. and adequate imo..
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I dont care what factories fit ;D
I use 215 55 16.. good price even in good brands .. and adequate imo..
Might struggle to get them on my 17" rims ;D ;D ;D ;D ;D ;D ;D
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I dont care what factories fit ;D
I use 215 55 16.. good price even in good brands .. and adequate imo..
Might struggle to get them on my 17" rims ;D ;D ;D ;D ;D ;D ;D
for the price of good brand 17 tires you can buy a set of wheels and good tires.. erm .. might be necessary to add some :P ;D
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and this is a tyre fitter....?
In short :-
yes, the speedo will be wrong - almost 4%, which is quite a large amount.
yes, the car will handle poorly - the suspension geometry is designed around the hub being 11.7 inches from the road. You're moving this up by half an inch, which is a massive amount, affecting handling, grip and stability under both cornering and braking.
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and this is a tyre fitter....?
In short :-
yes, the speedo will be wrong - almost 4%, which is quite a large amount.
yes, the car will handle poorly - the suspension geometry is designed around the hub being 11.7 inches from the road. You're moving this up by half an inch, which is a massive amount, affecting handling, grip and stability under both cornering and braking.
Bizzare as this may sound my speedo is only 1/2mph out from a gps reading. which is about right for a Vaux anyway on standard sized wheels.
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Also the bigger wheel diameter will have the effect of raising the gearing, so the car won't be as quick. Although might save a bit of fuel.
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the rules for speedo accuracy take account of the worst-case - which is I guess the smallest tyre diameter (after the tread has worn), plus the softest rubber, etc. So you tend to get between about 8% and 1% error
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Also the bigger wheel diameter will have the effect of raising the gearing, so the car won't be as quick. Although might save a bit of fuel.
Still quick enough :P
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Also the bigger wheel diameter will have the effect of raising the gearing, so the car won't be as quick. Although might save a bit of fuel.
Still quick enough :P
Er, no! actually. ;)
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the rules for speedo accuracy take account of the worst-case - which is I guess the smallest tyre diameter (after the tread has worn), plus the softest rubber, etc. So you tend to get between about 8% and 1% error
assume, speedo is out by %10.. what happens .. you know speedo reading is fake , so arrange your speed accordingly.. ;D
here there are many road radars (without police) (and I'm sure there also exist) showing your speed that you can compare yours without having gps..
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Also the bigger wheel diameter will have the effect of raising the gearing, so the car won't be as quick. Although might save a bit of fuel.
Still quick enough :P
Er, no! actually. ;)
Maybe yours isn't but the 40+ bhp I have over standard will make up for the huge tyres. :P
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the rules for speedo accuracy take account of the worst-case - which is I guess the smallest tyre diameter (after the tread has worn), plus the softest rubber, etc. So you tend to get between about 8% and 1% error
assume, speedo is out by %10.. what happens .. you know speedo reading is fake , so arrange your speed accordingly.. ;D
here there are many road radars (without police) (and I'm sure there also exist) showing your speed that you can compare yours without having gps..
Not here you just get flashing signs saying slow down.
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Maybe yours isn't but the 40+ bhp I have over standard will make up for the huge tyres. :P
(http://www.emoticonsfree.org/wp-content/uploads/party0052.gif)
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the rules for speedo accuracy take account of the worst-case - which is I guess the smallest tyre diameter (after the tread has worn), plus the softest rubber, etc. So you tend to get between about 8% and 1% error
assume, speedo is out by %10.. what happens .. you know speedo reading is fake , so arrange your speed accordingly.. ;D
here there are many road radars (without police) (and I'm sure there also exist) showing your speed that you can compare yours without having gps..
Not here you just get flashing signs saying slow down.
thats also ok :P
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the rules for speedo accuracy take account of the worst-case - which is I guess the smallest tyre diameter (after the tread has worn), plus the softest rubber, etc. So you tend to get between about 8% and 1% error
assume, speedo is out by %10.. what happens .. you know speedo reading is fake , so arrange your speed accordingly.. ;D
here there are many road radars (without police) (and I'm sure there also exist) showing your speed that you can compare yours without having gps..
Not here you just get flashing signs saying slow down.
thats also ok :P
Except all you know is your exceeding 30mph. By how much is anyones guess ;)
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Maybe yours isn't but the 40+ bhp I have over standard will make up for the huge tyres. :P
(http://www.emoticonsfree.org/wp-content/uploads/party0052.gif)
yes?
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Maybe yours isn't but the 40+ bhp I have over standard will make up for the huge tyres. :P
(http://www.emoticonsfree.org/wp-content/uploads/party0052.gif)
;D
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the rules for speedo accuracy take account of the worst-case - which is I guess the smallest tyre diameter (after the tread has worn), plus the softest rubber, etc. So you tend to get between about 8% and 1% error
assume, speedo is out by %10.. what happens .. you know speedo reading is fake , so arrange your speed accordingly.. ;D
here there are many road radars (without police) (and I'm sure there also exist) showing your speed that you can compare yours without having gps..
Not here you just get flashing signs saying slow down.
thats also ok :P
Except all you know is your exceeding 30mph. By how much is anyones guess ;)
you need few trials ;D :y
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Maybe yours isn't but the 40+ bhp I have over standard will make up for the huge tyres. :P
(http://www.emoticonsfree.org/wp-content/uploads/party0052.gif)
;D
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::)
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So how much did your 40bhp gain cost? If you don't mind me asking?
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::)
So how much did your 40bhp gain cost? If you don't mind me asking?
Nearly £2000
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::)
So how much did your 40bhp gain cost? If you don't mind me asking?
Nearly £2000
And the wheels and tyres?
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::)
So how much did your 40bhp gain cost? If you don't mind me asking?
Nearly £2000
And the wheels and tyres?
pass...
I can see what's coming though.
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::)
So how much did your 40bhp gain cost? If you don't mind me asking?
Nearly £2000
And the wheels and tyres?
pass...
I can see what's coming though.
Go on...
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::)
So how much did your 40bhp gain cost? If you don't mind me asking?
Nearly £2000
And the wheels and tyres?
pass...
I can see what's coming though.
Go on...
some form of criticism or how I know nothing and make false claims etc.
Anyway going off topic here. :-/
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::)
So how much did your 40bhp gain cost? If you don't mind me asking?
Nearly £2000
And the wheels and tyres?
pass...
I can see what's coming though.
Go on...
some form of criticism or how I know nothing and make false claims etc.
Anyway going off topic here. :-/
Well, 2k for 40bhp is a lot of dosh I'm sure you'll agree. I would be loathed to water that power gain down by spending even more cash on bigger wheels and tyres personally, but each to their own.
Thing is dif ratios can be changed to counter wheels size for a fraction of that cost. Or going further, a differemt lump altogether, v8 and straight 6 turbo lumps, although rare, have all been shoe horned into omegas giving total outputs from 350 to 400hp.
Adding wheels and tyres to your known bill, that cost is not far off ls1 v8 territory IMO. A certain member on this thread could have almost doubled the stock output for that money, given the car for a period.
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I agree with what your saying.
I did see a black v8 on pistonheads last year. very nice indeed.
Tbf once lowered it looked silly without having bigger wheels.
now I think about it the £££ figure might be slightly out.
Still have an ecu chip to fit and more has been done since it was dyno'd. im not expecting millions of bhp but its nice to see an increase.
also i'd hate trying to tell my insurance company my omega is a v8 lol
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I agree with what your saying.
I did see a black v8 on pistonheads last year. very nice indeed.
Tbf once lowered it looked silly without having bigger wheels.
now I think about it the £££ figure might be slightly out.
Still have an ecu chip to fit and more has been done since it was dyno'd. im not expecting millions of bhp but its nice to see an increase.
also i'd hate trying to tell my insurance company my omega is a v8 lol
It does go up of course. £900 for me. ;)
So what was modified?
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I agree with what your saying.
I did see a black v8 on pistonheads last year. very nice indeed.
Tbf once lowered it looked silly without having bigger wheels.
now I think about it the £££ figure might be slightly out.
Still have an ecu chip to fit and more has been done since it was dyno'd. im not expecting millions of bhp but its nice to see an increase.
also i'd hate trying to tell my insurance company my omega is a v8 lol
It does go up of course. £900 for me. ;)
So what was modified?
Both cats removed,
Courtenaysport cams (which allege to give +18bhp)
also remapped
Dual throttle enlarged and polished
magnecor leads
iridium plugs
and some other crap :/
As said still got the chip to fit and i really want some manifolds making as they're so restrictive
More labour cost than anything
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I agree with what your saying.
I did see a black v8 on pistonheads last year. very nice indeed.
Tbf once lowered it looked silly without having bigger wheels.
now I think about it the £££ figure might be slightly out.
Still have an ecu chip to fit and more has been done since it was dyno'd. im not expecting millions of bhp but its nice to see an increase.
also i'd hate trying to tell my insurance company my omega is a v8 lol
It does go up of course. £900 for me. ;)
So what was modified?
Both cats removed,
Courtenaysport cams (which allege to give +18bhp)
also remapped
Dual throttle enlarged and polished
magnecor leads
iridium plugs
and some other crap :/
As said still got the chip to fit and i really want some manifolds making as they're so restrictive
More labour cost than anything
I believe the reason that v8 mv6 came into being is because the owner fitted a super charger, giving something in the region of 260bhp on low boost, which blew the bottom end out destroying the stock v6 lump. So don't go too mad.
Although I'm not sure there is a 40 bhp gain in that list tbh. And no fuel regulator? :-X
Was this Courtney themselves?
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the camshaft work was. In all honesty not everything done was in my ownership I'm just finishing it off so to speak. I'm not trying to look cool and blag peoples heads, As I do know a lot more than I let on. tbf I think they dyno overead slightly, this is quite a common occurance with people seeing different results depending on where they take it for RR.
In terms of an FPR i'm currently trying to find a suitable one but had to buy 2 rear tyres yesterday :-/ :'(
As for the supercharger blowing up the bottom end thats undestandable with the amount of strain on the pullys even at low boost.
Shame they didn't sort the cooling issue out on the original prototype v8 omega
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the camshaft work was. In all honesty not everything done was in my ownership I'm just finishing it off so to speak. I'm not trying to look cool and blag peoples heads, As I do know a lot more than I let on. tbf I think they dyno overead slightly, this is quite a common occurance with people seeing different results depending on where they take it for RR.
In terms of an FPR i'm currently trying to find a suitable one but had to buy 2 rear tyres yesterday :-/ :'(
As for the supercharger blowing up the bottom end thats undestandable with the amount of strain on the pullys even at low boost.
Shame they didn't sort the cooling issue out on the original prototype v8 omega
(http://www.emoticonsfree.org/wp-content/uploads/party0052.gif)
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the camshaft work was. In all honesty not everything done was in my ownership I'm just finishing it off so to speak. I'm not trying to look cool and blag peoples heads, As I do know a lot more than I let on. tbf I think they dyno overead slightly, this is quite a common occurance with people seeing different results depending on where they take it for RR.
In terms of an FPR i'm currently trying to find a suitable one but had to buy 2 rear tyres yesterday :-/ :'(
As for the supercharger blowing up the bottom end thats undestandable with the amount of strain on the pullys even at low boost.
Shame they didn't sort the cooling issue out on the original prototype v8 omega
(http://www.emoticonsfree.org/wp-content/uploads/party0052.gif)
Meaning?
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Meaning?
Debate pending about whether or not a change of FPR will make any difference, etc., I would say. ;)
Quite often this is touted (by the likes of Courtenay) as a performance upgrade in itself. The truth of the matter is that, if you up the fuel pressure on a standard car, the stock ECU will just trim the fuelling back to where you originally were so it achieves nothing.
However, if you have made gains by fitting cams and a more free flowing exhaust, the injectors will be unable to supply much more fuel above a stock state of tune (they are at their limits with a standard engine IMHO) so upping the fuel pressure might be a good move. You would need to get it mapped with the new fuel pressure regulator though.
If you want to try it don't spend out on anything exotic. The 2.6/3.2 Omegas have a 3.8 Bar FPR as standard so just pick one up from a scrapper. :y
Kevin
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Meaning?
Debate pending about whether or not a change of FPR will make any difference, etc., I would say. ;)
Quite often this is touted (by the likes of Courtenay) as a performance upgrade in itself. The truth of the matter is that, if you up the fuel pressure on a standard car, the stock ECU will just trim the fuelling back to where you originally were so it achieves nothing.
However, if you have made gains by fitting cams and a more free flowing exhaust, the injectors will be unable to supply much more fuel above a stock state of tune (they are at their limits with a standard engine IMHO) so upping the fuel pressure might be a good move. You would need to get it mapped with the new fuel pressure regulator though.
If you want to try it don't spend out on anything exotic. The 2.6/3.2 Omegas have a 3.8 Bar FPR as standard so just pick one up from a scrapper. :y
Kevin
you speak a lot of sense mate :)
Truth be told in most instances they dont make a difference. but The opel tuning chip for the ecu combined with this should make a noticeable difference, so i am told but like most things results vary. Courtenay are not as good as hyped to be imho. If an adjustable comes up for the right price i'll have it.
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and this is a tyre fitter....?
In short :-
yes, the speedo will be wrong - almost 4%, which is quite a large amount.
yes, the car will handle poorly - the suspension geometry is designed around the hub being 11.7 inches from the road. You're moving this up by half an inch, which is a massive amount, affecting handling, grip and stability under both cornering and braking.
seems this thread has gone slightly of topic - was only asking about tyres ;D ;D ;D ;D
I was just asking for opinions on this idea. I would not have gone ahead & done it without some advice from the forum.It was a possibility but maybe not now. Seems it is not a good idea then 50 profile instead of 45 ?
Would the same bad handling issues occur if you used 18" rims & 40 profile tyres then ? :-/ :-/ :-/ :-/ :-/
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Did apologise earlier about the spamming sorry 8-)
All i can say is mine is lowered on shocks and springs and has 255 35 19s on the rear and 235 35 19s on the front . It handles well. but its never gonna keep up with a hot hatch etc. Its still a barge.
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Your speedo will be way out with 255/35 on a 19" rim
I used: http://www.miata.net/garage/tirecalc.html
(from this site I think) - 275/30 will keep it you all in sync
HTH
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Meaning?
Debate pending about whether or not a change of FPR will make any difference, etc., I would say. ;)
Quite often this is touted (by the likes of Courtenay) as a performance upgrade in itself. The truth of the matter is that, if you up the fuel pressure on a standard car, the stock ECU will just trim the fuelling back to where you originally were so it achieves nothing.
However, if you have made gains by fitting cams and a more free flowing exhaust, the injectors will be unable to supply much more fuel above a stock state of tune (they are at their limits with a standard engine IMHO) so upping the fuel pressure might be a good move. You would need to get it mapped with the new fuel pressure regulator though.
If you want to try it don't spend out on anything exotic. The 2.6/3.2 Omegas have a 3.8 Bar FPR as standard so just pick one up from a scrapper. :y
Kevin
:y
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Your speedo will be way out with 255/35 on a 19" rim
I used: http://www.miata.net/garage/tirecalc.html
(from this site I think) - 275/30 will keep it you all in sync
HTH
According to that link when I am doing 60mph I will actually be doing 61.8mph. I can live with that.
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I presume that Courtney have modified the block to address the cooling issues with the power increase?
Be interested to know what they did.
Also is this running on the standard exhaust manifolds?
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and this is a tyre fitter....?
In short :-
yes, the speedo will be wrong - almost 4%, which is quite a large amount.
yes, the car will handle poorly - the suspension geometry is designed around the hub being 11.7 inches from the road. You're moving this up by half an inch, which is a massive amount, affecting handling, grip and stability under both cornering and braking.
seems this thread has gone slightly of topic - was only asking about tyres ;D ;D ;D ;D
I was just asking for opinions on this idea. I would not have gone ahead & done it without some advice from the forum.It was a possibility but maybe not now. Seems it is not a good idea then 50 profile instead of 45 ?
Would the same bad handling issues occur if you used 18" rims & 40 profile tyres then ? :-/ :-/ :-/ :-/ :-/
looks like you thread as been hijacked!!
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and this is a tyre fitter....?
In short :-
yes, the speedo will be wrong - almost 4%, which is quite a large amount.
yes, the car will handle poorly - the suspension geometry is designed around the hub being 11.7 inches from the road. You're moving this up by half an inch, which is a massive amount, affecting handling, grip and stability under both cornering and braking.
seems this thread has gone slightly of topic - was only asking about tyres ;D ;D ;D ;D
I was just asking for opinions on this idea. I would not have gone ahead & done it without some advice from the forum.It was a possibility but maybe not now. Seems it is not a good idea then 50 profile instead of 45 ?
Would the same bad handling issues occur if you used 18" rims & 40 profile tyres then ? :-/ :-/ :-/ :-/ :-/
looks like you thread as been hijacked!!
Right outta my depth & too techie now Mark :o :o
& I was only asking about tyres ;D ;D ;D ;D
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I presume that Courtney have modified the block to address the cooling issues with the power increase?
Be interested to know what they did.
Also is this running on the standard exhaust manifolds?
Never gets hot so...... pass. not a concern lol
ex manifolds are standard, and restrictive as hell. looking into getting some made. i know someone on an x25xe used ford probe manifolds and welded the flanges on, whether this is possible on an x30 mounted the other way is something of a dark area.