Texx
Super Moderator
Original Article Credit: Fatman
Time and time again I hear the English crowd moaning about how their track is uphill and their times are never as good as anybody else. I'm getting pretty sick of it, so to try and help somebody over there finally run some decent times I've decided to post how I would build a Starlet to do 11's, knowledge gained from extensive reading and research, observation and experience.
I hate 'secret tuning', the practice of keeping anything successful close to your chest. It's sometimes understandable if you're in direct formal competition with somebody but within the car club community it has no place. If anybody has any criticism of anything I post I'm eager to hear it and likewise always open to suggestions!
Running 11's
It's not easy to break into the 11's and it's definitely not all about power!
At a minimum you need to be trapping around the 120mph mark to break into the 11's without running full slicks. To achieve that sort of end of track pace will require something in the region of 300-320bhp in a GT, slightly more in a Glanza. As I've been harping on about for some time, these sorts of figures ARE achievable on a stock motor, however given the track record and results of the tuning work I've seen over in your part of the world I would definitely recommend going to some forged internals for the sake of reliability. Don't think this makes your engine immune from potential problems, but it does give it more of a fighting chance.
Essential components:
Large injectors 440cc and raised fuel pressure at a minimum, preferably 510cc +.
A good standalone ECU There are plenty around with a huge graduation in price and features. It's pretty important you find a good tuner with results that speak for themselves. It's probably best to ask THEM what you should be running, while a good tuner should be able to tune just about anything, they are bound to have the most experience with one particular brand. For those on a budget and are willing to learn a Megasquirt based solution will work.
High quality manifold Preferably sch40 mild steel. You need strength here, cheapy stainless manifold NEED NOT APPLY. If you're interested in looks them get the manifold professionally coated. The coating will in theory also lead to a slightly quicker turbo spool. A short 'stock replacement' style manifold is a compromise between flow and packaging constraints. For this sort of application you want the best theoretical performance, this means long equal length runners and a proper merge collector.
Big turbo You need something that will flow the required air to produce the power, but you don't want anything to big. Enormous turbos aren't always faster. Ball bearing is nice, but not essential.
External wastegate These aren't a requirement on a street car but for drag use they are much more important. As back pressure is reduced (e.g big side exist exhaust) the internal wastegates effectiveness will be reduced, potentially to the point that you could have troubles with boost creep. Shoot this straight out the side too.
Large diameter exhaust short run side exit would be ideal, if only for use at the drag strip. Back pressure is the enemy, you really want just enough of an 'exhaust' to direct the hot gases somewhere they won't damage anything.
Good condition gearbox Preferably a C56 from a Glanza (better 3rd and 4th gear ratios) and a high quality aftermarket LSD (TRD is my preference). LSD is essential for a big power FWD car, the difference in getting off the line is night and day. If you don't have the money for an LSD, lock the diff, it'll work just as well for drag racing purposes. Just don't expect to drive it around every day.
High quality clutch There is quite a science behind clutch design, the important parts for drag racing are high point loading to give good bite off the line. A very heavy duty pressure plate and a 3/4/5 puck style friction plate achieves this nicely. Plenty of off the shelf designs for the EP.
Good tires! Street tires won't cut it at these sorts of power levels. The biggest part of cutting a good time at the strip is traction off the line. Locally we've had good success with Hoosier drag radials, however full slicks will give much better results. Unfortunately we aren't allowed to run these on street cars here, your rules may well be different. Use them if you can! Hoosier drag radials in 225-50-15 is the size you want. Combine these with a pair of the lightest 15x7 wheels you can find.
That's about it for the bare requirements to run 11's, there are a number of optional components or things you can do to enhance your times.
Helpful additions
Aftermarket intake manifold These can have significant benefits, primarily you want a larger plenum volume with shorter runners, preferably with bell mouth runner entry and a larger throttle body wouldn't hurt either
Ported head with cams and valve springs. A stock 5e-fhe head will definitely flow enough to make the power required to break 11's, however there is no harm in making it easier with increased head flow. This will also allow you to increase your rev limit, allowing a shorter final drive for more rapid acceleration whilst still achieving the trap speeds required in 4th gear.
Shorter final drive from a Corolla/levin/trueno. There are several different final drives, these will effectively shorten your gears and potentially make you faster. You must choose carefully as you want to make sure you don't have to shift into 5th gear to achieve the trap speeds required for the ET. This will depend on tire size and rev limit more than anything.
Coilover suspension - this is optional but very helpful. As drag tires are significantly larger than your road going tires, you may well need to raise the front of the car to clear them, especially full slicks which expand out at speed due to the soft sidewall construction. Just as critical is adjustment at the rear, you want a slight forward rake (higher at the back) and very stiff springs/damper settings to minimise weight transfer to the back axle. This weight transfer reduces effective traction on the front and can make a large difference to your 60' and thus ET's. 12+ kg/mm springs in the rear would be a good starting rate.
Weight reduction, while this isn't critical, it will definitely help in every aspect of the performance of the car. Specifically you want to end up with as much front bias as you can, e.g strip everything you can out of the back! More weight over the driven wheels means more traction.
Launch control/flat shifting Launch control is a great aid for consistency and speed off the line, flat shifting ensures you don't fall off boost between gears. This is hard on your drivetrain and requires an excellent quality clutch!
Technique:
The Launch: In a fwd car, shaving .1 of a second off your 60' time will result in .2-.3 of a second off your final ET at the end of the track. In other words, the launch is critical. Balls it up and bog down, goodbye to a quick time. Just as harmful is excessive wheelspin. Launch control or a 2 step rev limiter that you can easily adjust is a HUGE help here, you have the ability to dial in the ideal launch RPM for a given track and surface condition. On full slicks on a good day you may very well be launching at 6000rpm, on street tires or drag radials 2500rpm might be more appropriate. This will vary wildly between cars and the day.
Burnout: On street tires or drag radials your burnout is primarily to clean the surface of the tires, removing any mud/stones or other debris. A GIANT skid will actually HURT your times on street level rubber, excessive heat will negatively affect traction. a second or so in 1st or 2nd gear is enough.
If you're running full drag slicks (which are a topic unto themselves) then the burnout is a bit more involved. The goal is to put heat into the tire both from surface friction and deformation of the sidewall. Here you'll be wanting 2nd gear (or possibly 3rd, gearbox/clutch dependant) and pretty much as much smoke as you can get before you drag yourself over the line. 2-3 seconds is probably all you'll get out of it.
Tire pressure: Essential part of the tuning process. On street rubber (Toyo R888's in my case) dropping from 30psi to 15psi resulted in a consistant .3 second difference in my 60', adding up to almost a second off my ET. Street tires will always do significantly better with dropped pressure, to a point. Drag radials are a little different, lower pressures are good but you can go too low and the ideal pressure is probably *higher* than in a street tire. Full slicks use VERY low tire pressures, usually under 10psi. Along with their soft sidewall construction this allows a much larger contact patch and hugely improved straight line traction.
Everything I've mentioned will help towards running quick times, but it's by no means an exhaustive write up (despite the apparent length of this post).
It will likely take many runs and a lot of small changes before you start to see the times you're looking for, expect it to be a gradual process. Alfradio is a great example of this, he's been slowly chipping away at his ET's for quite some time now and just recently broke into the 12's, originally starting off in the 15's.
Time and time again I hear the English crowd moaning about how their track is uphill and their times are never as good as anybody else. I'm getting pretty sick of it, so to try and help somebody over there finally run some decent times I've decided to post how I would build a Starlet to do 11's, knowledge gained from extensive reading and research, observation and experience.
I hate 'secret tuning', the practice of keeping anything successful close to your chest. It's sometimes understandable if you're in direct formal competition with somebody but within the car club community it has no place. If anybody has any criticism of anything I post I'm eager to hear it and likewise always open to suggestions!
Running 11's
It's not easy to break into the 11's and it's definitely not all about power!
At a minimum you need to be trapping around the 120mph mark to break into the 11's without running full slicks. To achieve that sort of end of track pace will require something in the region of 300-320bhp in a GT, slightly more in a Glanza. As I've been harping on about for some time, these sorts of figures ARE achievable on a stock motor, however given the track record and results of the tuning work I've seen over in your part of the world I would definitely recommend going to some forged internals for the sake of reliability. Don't think this makes your engine immune from potential problems, but it does give it more of a fighting chance.
Essential components:
Large injectors 440cc and raised fuel pressure at a minimum, preferably 510cc +.
A good standalone ECU There are plenty around with a huge graduation in price and features. It's pretty important you find a good tuner with results that speak for themselves. It's probably best to ask THEM what you should be running, while a good tuner should be able to tune just about anything, they are bound to have the most experience with one particular brand. For those on a budget and are willing to learn a Megasquirt based solution will work.
High quality manifold Preferably sch40 mild steel. You need strength here, cheapy stainless manifold NEED NOT APPLY. If you're interested in looks them get the manifold professionally coated. The coating will in theory also lead to a slightly quicker turbo spool. A short 'stock replacement' style manifold is a compromise between flow and packaging constraints. For this sort of application you want the best theoretical performance, this means long equal length runners and a proper merge collector.
Big turbo You need something that will flow the required air to produce the power, but you don't want anything to big. Enormous turbos aren't always faster. Ball bearing is nice, but not essential.
External wastegate These aren't a requirement on a street car but for drag use they are much more important. As back pressure is reduced (e.g big side exist exhaust) the internal wastegates effectiveness will be reduced, potentially to the point that you could have troubles with boost creep. Shoot this straight out the side too.
Large diameter exhaust short run side exit would be ideal, if only for use at the drag strip. Back pressure is the enemy, you really want just enough of an 'exhaust' to direct the hot gases somewhere they won't damage anything.
Good condition gearbox Preferably a C56 from a Glanza (better 3rd and 4th gear ratios) and a high quality aftermarket LSD (TRD is my preference). LSD is essential for a big power FWD car, the difference in getting off the line is night and day. If you don't have the money for an LSD, lock the diff, it'll work just as well for drag racing purposes. Just don't expect to drive it around every day.
High quality clutch There is quite a science behind clutch design, the important parts for drag racing are high point loading to give good bite off the line. A very heavy duty pressure plate and a 3/4/5 puck style friction plate achieves this nicely. Plenty of off the shelf designs for the EP.
Good tires! Street tires won't cut it at these sorts of power levels. The biggest part of cutting a good time at the strip is traction off the line. Locally we've had good success with Hoosier drag radials, however full slicks will give much better results. Unfortunately we aren't allowed to run these on street cars here, your rules may well be different. Use them if you can! Hoosier drag radials in 225-50-15 is the size you want. Combine these with a pair of the lightest 15x7 wheels you can find.
That's about it for the bare requirements to run 11's, there are a number of optional components or things you can do to enhance your times.
Helpful additions
Aftermarket intake manifold These can have significant benefits, primarily you want a larger plenum volume with shorter runners, preferably with bell mouth runner entry and a larger throttle body wouldn't hurt either
Ported head with cams and valve springs. A stock 5e-fhe head will definitely flow enough to make the power required to break 11's, however there is no harm in making it easier with increased head flow. This will also allow you to increase your rev limit, allowing a shorter final drive for more rapid acceleration whilst still achieving the trap speeds required in 4th gear.
Shorter final drive from a Corolla/levin/trueno. There are several different final drives, these will effectively shorten your gears and potentially make you faster. You must choose carefully as you want to make sure you don't have to shift into 5th gear to achieve the trap speeds required for the ET. This will depend on tire size and rev limit more than anything.
Coilover suspension - this is optional but very helpful. As drag tires are significantly larger than your road going tires, you may well need to raise the front of the car to clear them, especially full slicks which expand out at speed due to the soft sidewall construction. Just as critical is adjustment at the rear, you want a slight forward rake (higher at the back) and very stiff springs/damper settings to minimise weight transfer to the back axle. This weight transfer reduces effective traction on the front and can make a large difference to your 60' and thus ET's. 12+ kg/mm springs in the rear would be a good starting rate.
Weight reduction, while this isn't critical, it will definitely help in every aspect of the performance of the car. Specifically you want to end up with as much front bias as you can, e.g strip everything you can out of the back! More weight over the driven wheels means more traction.
Launch control/flat shifting Launch control is a great aid for consistency and speed off the line, flat shifting ensures you don't fall off boost between gears. This is hard on your drivetrain and requires an excellent quality clutch!
Technique:
The Launch: In a fwd car, shaving .1 of a second off your 60' time will result in .2-.3 of a second off your final ET at the end of the track. In other words, the launch is critical. Balls it up and bog down, goodbye to a quick time. Just as harmful is excessive wheelspin. Launch control or a 2 step rev limiter that you can easily adjust is a HUGE help here, you have the ability to dial in the ideal launch RPM for a given track and surface condition. On full slicks on a good day you may very well be launching at 6000rpm, on street tires or drag radials 2500rpm might be more appropriate. This will vary wildly between cars and the day.
Burnout: On street tires or drag radials your burnout is primarily to clean the surface of the tires, removing any mud/stones or other debris. A GIANT skid will actually HURT your times on street level rubber, excessive heat will negatively affect traction. a second or so in 1st or 2nd gear is enough.
If you're running full drag slicks (which are a topic unto themselves) then the burnout is a bit more involved. The goal is to put heat into the tire both from surface friction and deformation of the sidewall. Here you'll be wanting 2nd gear (or possibly 3rd, gearbox/clutch dependant) and pretty much as much smoke as you can get before you drag yourself over the line. 2-3 seconds is probably all you'll get out of it.
Tire pressure: Essential part of the tuning process. On street rubber (Toyo R888's in my case) dropping from 30psi to 15psi resulted in a consistant .3 second difference in my 60', adding up to almost a second off my ET. Street tires will always do significantly better with dropped pressure, to a point. Drag radials are a little different, lower pressures are good but you can go too low and the ideal pressure is probably *higher* than in a street tire. Full slicks use VERY low tire pressures, usually under 10psi. Along with their soft sidewall construction this allows a much larger contact patch and hugely improved straight line traction.
Everything I've mentioned will help towards running quick times, but it's by no means an exhaustive write up (despite the apparent length of this post).
It will likely take many runs and a lot of small changes before you start to see the times you're looking for, expect it to be a gradual process. Alfradio is a great example of this, he's been slowly chipping away at his ET's for quite some time now and just recently broke into the 12's, originally starting off in the 15's.