Ultimate road spec Ultima GTR
Discussion
Hi all
Im trying to make my GTR more useable and pleasant to live with, i am interested in what you guys think....
My thoughts are
1 ditch the SBC, even with a good EFI system it simply is not smooth enough to use with our road conditions, i didnt buy a Ultima for its fuel economy but it simply has to be a concern at £5.50 a gallon and only a best of 15mpg.
2 ditch the red gel coat, my car is starting to look terrible with black streaks starting to appear. This means i dont want to use the car if its sunny else it will make the situation worse.
3 improve the aircon, you simply cant drive the car on a hot day its unpleasant.
4 ditch the Getrag for some decent ratios which will also help with point 1.
5 design some kind of panelling under the front and rear clips so every time you go out its not a major cleaning exercise.
solutions
1 LS7 with a good aftermarket stand alone ECU which should improve driveability and economy. I have been told a LS7 will return 24mpg on a steady run. The LS7 is designed to handle 500bhp so as a result it should be reliable??
2 paint the car and use some front end stone chip protection, and also improve the front light binnacles.
3 working on this one
4 A G50, with cable shift with good ratios to match a 650bhp LS7
5 in progress.
Most of this has been covered but have you any bits you would add to improve the car. I will do some trackdays and i want to have a go at fighting torque, but i would rather it be more pleasant to drive on the road than a trackday monster.
Im trying to make my GTR more useable and pleasant to live with, i am interested in what you guys think....
My thoughts are
1 ditch the SBC, even with a good EFI system it simply is not smooth enough to use with our road conditions, i didnt buy a Ultima for its fuel economy but it simply has to be a concern at £5.50 a gallon and only a best of 15mpg.
2 ditch the red gel coat, my car is starting to look terrible with black streaks starting to appear. This means i dont want to use the car if its sunny else it will make the situation worse.
3 improve the aircon, you simply cant drive the car on a hot day its unpleasant.
4 ditch the Getrag for some decent ratios which will also help with point 1.
5 design some kind of panelling under the front and rear clips so every time you go out its not a major cleaning exercise.
solutions
1 LS7 with a good aftermarket stand alone ECU which should improve driveability and economy. I have been told a LS7 will return 24mpg on a steady run. The LS7 is designed to handle 500bhp so as a result it should be reliable??
2 paint the car and use some front end stone chip protection, and also improve the front light binnacles.
3 working on this one
4 A G50, with cable shift with good ratios to match a 650bhp LS7
5 in progress.
Most of this has been covered but have you any bits you would add to improve the car. I will do some trackdays and i want to have a go at fighting torque, but i would rather it be more pleasant to drive on the road than a trackday monster.
Sure the LS7 is far better than an SBC, but you're asking about an 'ultimate' road car. Is the LS7 a good road engine? I don't know - that's for someone else (who's driven one) to comment on. My own thoughts are to also open your mind to other 'non-chevy' engines. There's a LOT to choose from.
Paint and armourfend are a FAR better way forward IMHO!
The front / rear clip 'grot-trap' solutions were one of the the first things I did to my kit when I got it. How anyone can drive their car with all that s
te rattling around under the clips is beyond me. It's such an easy fix... no idea why the factory have never changed the clip designs to improve this!
Can't really comment on your other Q's as I've never used those bits of kit... mind you - would it not be better to hang onto your Getrag until you've chosen / fitted your new choice of engine? Your ratio's may not be such a problem on another powerplant!
Paint and armourfend are a FAR better way forward IMHO!
The front / rear clip 'grot-trap' solutions were one of the the first things I did to my kit when I got it. How anyone can drive their car with all that s
te rattling around under the clips is beyond me. It's such an easy fix... no idea why the factory have never changed the clip designs to improve this!Can't really comment on your other Q's as I've never used those bits of kit... mind you - would it not be better to hang onto your Getrag until you've chosen / fitted your new choice of engine? Your ratio's may not be such a problem on another powerplant!
Regarding point 1.
I have an LT5 motor which is kinda halfway house between a LS7 and SBC. It always starts on the button and gives around 23mpg when cruising (as it runs on the single fuel rail). It mimics the dimensions of the SBC so bolts right in.
Spec is all alloy block, efi, quad cam, 32 valve, cossie designed head but built to Chevs standards e.g. simple servicing and reliability.
Power on mine is around 420 but there are kits to take it to 550.
Check it out on wikipedia, might be good compromise if you can find one.
(oh, also seems to sit a lot lower than SBC's I've seen, plus exhuasts are routed under the car so no real engine bay heat issues. I gotta post some photos soon).
(oh oh, also lovely balance and sound to the motor as well, rev it to 6000 and it's got minimal movement and on the track pops and bangs small flames through the exhuasts due to remapped efi).
I have an LT5 motor which is kinda halfway house between a LS7 and SBC. It always starts on the button and gives around 23mpg when cruising (as it runs on the single fuel rail). It mimics the dimensions of the SBC so bolts right in.
Spec is all alloy block, efi, quad cam, 32 valve, cossie designed head but built to Chevs standards e.g. simple servicing and reliability.
Power on mine is around 420 but there are kits to take it to 550.
Check it out on wikipedia, might be good compromise if you can find one.
(oh, also seems to sit a lot lower than SBC's I've seen, plus exhuasts are routed under the car so no real engine bay heat issues. I gotta post some photos soon).
(oh oh, also lovely balance and sound to the motor as well, rev it to 6000 and it's got minimal movement and on the track pops and bangs small flames through the exhuasts due to remapped efi).
Scotty-Boy said:
Sure the LS7 is far better than an SBC, but you're asking about an 'ultimate' road car. Is the LS7 a good road engine? I don't know - that's for someone else (who's driven one) to comment on. My own thoughts are to also open your mind to other 'non-chevy' engines. There's a LOT to choose from.
Paint and armourfend are a FAR better way forward IMHO!
The front / rear clip 'grot-trap' solutions were one of the the first things I did to my kit when I got it. How anyone can drive their car with all that ste rattling around under the clips is beyond me. It's such an easy fix... no idea why the factory have never changed the clip designs to improve this!
Can't really comment on your other Q's as I've never used those bits of kit... mind you - would it not be better to hang onto your Getrag until you've chosen / fitted your new choice of engine? Your ratio's may not be such a problem on another powerplant!
i know what you mean but the other power plants do not make much sense to me!!Paint and armourfend are a FAR better way forward IMHO!
The front / rear clip 'grot-trap' solutions were one of the the first things I did to my kit when I got it. How anyone can drive their car with all that s
te rattling around under the clips is beyond me. It's such an easy fix... no idea why the factory have never changed the clip designs to improve this!Can't really comment on your other Q's as I've never used those bits of kit... mind you - would it not be better to hang onto your Getrag until you've chosen / fitted your new choice of engine? Your ratio's may not be such a problem on another powerplant!
I want to mod the front clip so i can fit some bigger front tyres ie 255 toyo 888's will they fit on the standard front rims??
Kyle, are you planning to be at 500hp then increase to 650 for track days (points 1 + 4)?
Have you considered going the blower route, super or turbo?
Far milder cams, lighter valve train with all its pros and increased longevity too....... plus vastly improved economy, manners and potential HP! You also have the benefit of EFI to compliment your combo.
Your current motor would not need too many internal mods...cam/pistons mainly..... maybe improved exhaust valves.
Also you could easily adjust the setup to suit the HP mood!
A short stroke 377 with a blower would be a real interesting motor and quite lively too.
Just on your colour dilemma.....if you are planning to completely change be careful going lighter.......reds, even when fully over-primed, have a habit of bleed-through over a period. Whites and pale silvers become pale pinks, yellows can turn golden/orange. The fix is to put a black undercoat on first!
Good to hear you are keeping your Ultima now!
Have you considered going the blower route, super or turbo?
Far milder cams, lighter valve train with all its pros and increased longevity too....... plus vastly improved economy, manners and potential HP! You also have the benefit of EFI to compliment your combo.
Your current motor would not need too many internal mods...cam/pistons mainly..... maybe improved exhaust valves.
Also you could easily adjust the setup to suit the HP mood!
A short stroke 377 with a blower would be a real interesting motor and quite lively too.
Just on your colour dilemma.....if you are planning to completely change be careful going lighter.......reds, even when fully over-primed, have a habit of bleed-through over a period. Whites and pale silvers become pale pinks, yellows can turn golden/orange. The fix is to put a black undercoat on first!
Good to hear you are keeping your Ultima now!
738 driver said:
Kyle, are you planning to be at 500hp then increase to 650 for track days (points 1 + 4)?
Have you considered going the blower route, super or turbo?
Far milder cams, lighter valve train with all its pros and increased longevity too....... plus vastly improved economy, manners and potential HP! You also have the benefit of EFI to compliment your combo.
Your current motor would not need too many internal mods...cam/pistons mainly..... maybe improved exhaust valves.
Also you could easily adjust the setup to suit the HP mood!
A short stroke 377 with a blower would be a real interesting motor and quite lively too.
Just on your colour dilemma.....if you are planning to completely change be careful going lighter.......reds, even when fully over-primed, have a habit of bleed-through over a period. Whites and pale silvers become pale pinks, yellows can turn golden/orange. The fix is to put a black undercoat on first!
Good to hear you are keeping your Ultima now!
Hi DaveHave you considered going the blower route, super or turbo?
Far milder cams, lighter valve train with all its pros and increased longevity too....... plus vastly improved economy, manners and potential HP! You also have the benefit of EFI to compliment your combo.
Your current motor would not need too many internal mods...cam/pistons mainly..... maybe improved exhaust valves.
Also you could easily adjust the setup to suit the HP mood!
A short stroke 377 with a blower would be a real interesting motor and quite lively too.
Just on your colour dilemma.....if you are planning to completely change be careful going lighter.......reds, even when fully over-primed, have a habit of bleed-through over a period. Whites and pale silvers become pale pinks, yellows can turn golden/orange. The fix is to put a black undercoat on first!
Good to hear you are keeping your Ultima now!
How will a supercharger give better ecomomy?? I have been offered a twin turbo motor in exchange for mine??
If thinking of going with the Gulf colour scheme, so i will bear in mind what you have said thanks.
I never really wanted to sell but i do want to make the car more enjoyable to use own.
thanks Kyle
kylemrushall said:
Scotty-Boy said:
I want to mod the front clip so i can fit some bigger front tyres ie 255 toyo 888's will they fit on the standard front rims??
There is a thread on here somewhere that somebody has been running 255's with no issues (I believe) although problems were encountered with 265's (understandably).I was wondering whether we could squeeze an extra 0.5" or 1" on the rim width if we closed down the offset???
[quote=J&j]
I was wondering whether we could squeeze an extra 0.5" or 1" on the rim width if we closed down the offset???I cant see 255's fitting with no issues!!! My 235's rub the headlight shrouds!!
kylemrushall said:
Scotty-Boy said:
I want to mod the front clip so i can fit some bigger front tyres ie 255 toyo 888's will they fit on the standard front rims??
There is a thread on here somewhere that somebody has been running 255's with no issues (I believe) although problems were encountered with 265's (understandably).I was wondering whether we could squeeze an extra 0.5" or 1" on the rim width if we closed down the offset???
Kyle, the supercharger/turbo method basically assists the engine to breath, by force feeding the air into the cylinders.
In a non-blower engine getting every bit of each cylinder filled properly all across its power range is not possible, mainly because of all restrictions along the airflow path, and the time delay in doing so, even the route the air has to take once its in the cylinder is a nightmare. In an attempt to resolve this a lot of research and development goes into induction systems, heads, valves, combustion chamber shape (including piston top) and the exhaust system. But perhaps most importantly the camshaft design (profile). Remember this non-turbo (normally aspirated) engine has to suck its air into itself before it can do anything productive with it. The camshaft 'profile' is the main governing factor as to how much and at what speed (engine rpm) the engine will 'draw' an appropriate volume of air.
Now if you want a particular engine design, in our case the SBC, to produce more than standard HP, we have to seriously modify the cam profile and sometimes, to a lesser degree, the other bits which help the engine breath. This is okay but for large hp increases the gains we seek occur at increased RPM. By incresing the port time-area on the induction profile we allow the engine to suck more air at a higher RPM.... and give us more HP! Remember this drawing of air principle is slightly delayed as the engine has to accelerate first to then create the larger demand for air required as it accelerates towards peak power.At the cam profiles' peak power the valves will be opening and closing at just the right time to maximise the requirement of the engine and all its breathing bits. Unfortunately because the engine has to suck its air and has all those obstacles in the intake path a lot of the air at lower RPM (the inefficeint power area) goes straight out of the exhaust. That's not so bad apart from the fact that fuel is mixed with it before it enters the cylinder. With EFI you can reduce these losses but never fully.
So in the normally aspirated situation the engine is quite a compromise as the cam to produce the extra power, wastes fuel in several areas. Remember we also need stronger valve springs to control a larger cam profile, maybe bigger heavier valves too, then solid roller lifters, then a rev kit and so-on and so-on. All these items with their increased frictional loads cause loss of power (to drive them), extra heat and frequently, with very wild cams, vastly increased wear on all the valve-train.
Jeez-------- the price of power!
As soon as you pump the air into the engine, that wild cam profile can be tamed considerably as the excess time-area needed to fill each cylinder effectively in the normally aspirated engine case, is no longer required.
Therefore, in most cases a blower of some sorts helps all-round, many of those fast wearing induction parts can be done away with and the engine made quite efficient.
As Dave has demonstrated, he can change his supercharger set-up to suit his requirements and has gained excellent all-round results... a top man!
Turbos are generally a bit simpler to install and work well with EFI but have more initial heat to deal with than a supercharger, also a little more lag!
So basically.... when you pump air into your motor you make it far easier for it to breath and hence produce power, even from very low to quite high RPM if done correctly. This should increase its efficiency and hence economy too when compared to normally aspirated performance motors.
There's at least several books worth of theory on subjects like volumetric efficiency but hopefully this will have given a basic answer to your question.
Standing by for the engine gurus' bashing!
In a non-blower engine getting every bit of each cylinder filled properly all across its power range is not possible, mainly because of all restrictions along the airflow path, and the time delay in doing so, even the route the air has to take once its in the cylinder is a nightmare. In an attempt to resolve this a lot of research and development goes into induction systems, heads, valves, combustion chamber shape (including piston top) and the exhaust system. But perhaps most importantly the camshaft design (profile). Remember this non-turbo (normally aspirated) engine has to suck its air into itself before it can do anything productive with it. The camshaft 'profile' is the main governing factor as to how much and at what speed (engine rpm) the engine will 'draw' an appropriate volume of air.
Now if you want a particular engine design, in our case the SBC, to produce more than standard HP, we have to seriously modify the cam profile and sometimes, to a lesser degree, the other bits which help the engine breath. This is okay but for large hp increases the gains we seek occur at increased RPM. By incresing the port time-area on the induction profile we allow the engine to suck more air at a higher RPM.... and give us more HP! Remember this drawing of air principle is slightly delayed as the engine has to accelerate first to then create the larger demand for air required as it accelerates towards peak power.At the cam profiles' peak power the valves will be opening and closing at just the right time to maximise the requirement of the engine and all its breathing bits. Unfortunately because the engine has to suck its air and has all those obstacles in the intake path a lot of the air at lower RPM (the inefficeint power area) goes straight out of the exhaust. That's not so bad apart from the fact that fuel is mixed with it before it enters the cylinder. With EFI you can reduce these losses but never fully.
So in the normally aspirated situation the engine is quite a compromise as the cam to produce the extra power, wastes fuel in several areas. Remember we also need stronger valve springs to control a larger cam profile, maybe bigger heavier valves too, then solid roller lifters, then a rev kit and so-on and so-on. All these items with their increased frictional loads cause loss of power (to drive them), extra heat and frequently, with very wild cams, vastly increased wear on all the valve-train.
Jeez-------- the price of power!
As soon as you pump the air into the engine, that wild cam profile can be tamed considerably as the excess time-area needed to fill each cylinder effectively in the normally aspirated engine case, is no longer required.
Therefore, in most cases a blower of some sorts helps all-round, many of those fast wearing induction parts can be done away with and the engine made quite efficient.
As Dave has demonstrated, he can change his supercharger set-up to suit his requirements and has gained excellent all-round results... a top man!
Turbos are generally a bit simpler to install and work well with EFI but have more initial heat to deal with than a supercharger, also a little more lag!
So basically.... when you pump air into your motor you make it far easier for it to breath and hence produce power, even from very low to quite high RPM if done correctly. This should increase its efficiency and hence economy too when compared to normally aspirated performance motors.
There's at least several books worth of theory on subjects like volumetric efficiency but hopefully this will have given a basic answer to your question.
Standing by for the engine gurus' bashing!
Scotty-Boy said:
The front / rear clip 'grot-trap' solutions were one of the the first things I did to my kit when I got it. How anyone can drive their car with all that ste rattling around under the clips is beyond me. It's such an easy fix... no idea why the factory have never changed the clip designs to improve this!
Can you please expand on this? I don't understand what you're referring to? Pics would help a lot.te rattling around under the clips is beyond me. It's such an easy fix... no idea why the factory have never changed the clip designs to improve this!Thanks,
Paul
kylemrushall said:
Hi all
4 ditch the Getrag for some decent ratios which will also help with point 1.
4 A G50, with cable shift with good ratios to match a 650bhp LS7
You can get decent/better/more suitable ratios for the Getrag too... No need to change the box per se (and if you were running a G50, you'd need to change them anyway)...4 ditch the Getrag for some decent ratios which will also help with point 1.
4 A G50, with cable shift with good ratios to match a 650bhp LS7
http://www.albinsgear.com.au/pGearsets.html
The 0.68:1 overdrive top ratio would be good for 230mph at 7000rpm on stock Ultima tyres... "Theoretically" (ie. if you'd got enough power and enough space to reach 230mph)...
Graham-P said:
martinlaw said:
is there anyone in the uk who can strip down Getrag boxes and change the ratios at a reasonable cost?
Martin.
Not the last time I looked........you need a 50+ton press to extract the gear stack!!!Martin.
When I asked about CW&P change it wasn't really an option.
The G50 can run on cables now, it also can be geared however you want it.
Would you be interested in part exing your Getrags for G50's with the ratios of your choice??????
robm3 said:
Regarding point 1.
I have an LT5 motor which is kinda halfway house between a LS7 and SBC. It always starts on the button and gives around 23mpg when cruising (as it runs on the single fuel rail). It mimics the dimensions of the SBC so bolts right in.
Spec is all alloy block, efi, quad cam, 32 valve, cossie designed head but built to Chevs standards e.g. simple servicing and reliability.
Power on mine is around 420 but there are kits to take it to 550.
Check it out on wikipedia, might be good compromise if you can find one.
(oh, also seems to sit a lot lower than SBC's I've seen, plus exhuasts are routed under the car so no real engine bay heat issues. I gotta post some photos soon).
(oh oh, also lovely balance and sound to the motor as well, rev it to 6000 and it's got minimal movement and on the track pops and bangs small flames through the exhuasts due to remapped efi).
hmmmmm now thats a diffrent engine choice! I have an LT5 motor which is kinda halfway house between a LS7 and SBC. It always starts on the button and gives around 23mpg when cruising (as it runs on the single fuel rail). It mimics the dimensions of the SBC so bolts right in.
Spec is all alloy block, efi, quad cam, 32 valve, cossie designed head but built to Chevs standards e.g. simple servicing and reliability.
Power on mine is around 420 but there are kits to take it to 550.
Check it out on wikipedia, might be good compromise if you can find one.
(oh, also seems to sit a lot lower than SBC's I've seen, plus exhuasts are routed under the car so no real engine bay heat issues. I gotta post some photos soon).
(oh oh, also lovely balance and sound to the motor as well, rev it to 6000 and it's got minimal movement and on the track pops and bangs small flames through the exhuasts due to remapped efi).
i have heard a little aboutt he LT5's but not a lot. would like tio see some picks!
Chris.
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