hard-tuning a dc2r - how effective?

[szymonsta]

i am currently doing 1:23's around mallala in my dc2r, with a very light-tune setup. just RE55s, endless na-r pads and zeal front rotors, zeal function xs coilovers, vision camber kits, mugen sump, koyo radiator, m-bit headers, jdm cat, fgk pg exhaust and mugen n1 ecu.
i beleive my driving and setup limit would be high 1:22's. as a guide funkyR has done low 1:21's in his 222kw@wheels evo9 on stock tyres.

how much of an effect on lap times would the following mods have?
*cam upgrade eg toda b, cam-gears, valvesprings, apexi power fc tuned, perhaps a mugen intake and de-cat pipe, lightened flywheel and clutch upgrade.

do any of the guys here with circuit experience have any suggestions or advice? would these mods have a signifficant impact on lap times?

[Jingers]

too hard to say depends on the track lay out and also the gear ratios

[Criz R]

and the power output of the combination outlined above

[freakie]

szy, what sort of rpms are you seeing in the mid and slower corners? if your finding that you have to feather your throttle at certain points to avoid upshifting/downshifting into a corner, or that your rpms are either too high in 2nd and too low in 3rd, a clutch and flywheel with closer ratios or modified ratios will gain you better times than even up to 10kws.

[szymonsta]

freakie, no the stock ratios are fairly well suited to the track..never really need to feather the throttle, its floored most of the time (the brakes being floored the remaining time).

ok not mallala specific, then, but as a general rule, how much of an affect will say an extra 20kw of midrange-to high rpm power have on laptimes?

i think there is a few regular tracksters on here with some experience driving their cars in different stages of development..for example i can say s-tyres made about 3seconds difference vs standard tyres. i would be interested to know what kind of an impact on lap times these guys experienced when upgrading from near-stock power..

[tinkerbell]

i did a 1.14.9 in a stock integra VTiR with coil-overs, JDM 4-1 headers and endless brake pads at wakefield (on 18 month old hard Toyo RA1's)

now with 120kw b20vtec and more mods i only do 1.12.3's (on similar tyres)

so more power is really not worth that much more...

[VTECMACHINE]

The most beneficial modification would definately have to be a lightened flywheel. Also a tune with a Power FC would be good.

Toda B's would be good on a short, slow, winding track like Wakefield. Don't know much about the track you go to.

The Mugen intake is great... but why not try a cheaper option first. Trust foam filter in stock airbox, remove the resignator in the front right guard (takes out weight too ), and then get air con piping, and duct it to the front bar from the air box. This is really good.. I had it in my DC2R before the Mugen Intake, and its alot cheaper too!

Strip your car, but make sure it's balenced... play around with coilover heights. Best mod IMO, and also get a harness (you'll actually be quicker - PROMISE). And to protect your engine, get a oil cooler, if you don't already have one!

hope that helped you a bit...

[szymonsta]

thanks tinks & vtecmachine. this is what i expected. once u get past light tune mods, u can spend big bucks for small improvements..
vtecmachine, i usually remove rear seats and everything from the boot (spare wheel etc) for a track day. and i have previously spent MONTHS setting up the coilovers, where i now have a setting i am very happy with. the car is very balanceed around the track with neutral handling characteristics, to slight oversteer on some coners

i dont have any $ to spend on the car for a while, but eventually i may get clutch and lightened flywheel upgrade.

[00dc2]

and intake

[Jingers]

my thoughts are that its ok to hard tune but the light tune is make the least amount of comprimises interms of comfort/driveability.

Once u get past the light mods you SEVERLY compromise driveability/comfort/etc etc.......

it is up to you as the owner of the car to decide if it is worth it or not .....

[freakie]

To give you an idea:

Winton Raceway long track, stock b18cr, stock car 1.45:33

Added I/H/E + vafc 1.44.3 Not a huge gain in peak power, but midrange power really gained alot (7-10kws throughout the rpm range)

Clutch/Fly & 3/4th gears and first/final 1.42.2 most of the gain was from the sweeper and the entry into a series of 3 slow corners (called the cows tits).

Switched from bridgestone g3's to r888 toyo 1.40.5

Then, i lost track as i fully stripped the car and went to a cage and changed to a turbo setup.

In light of this however, from the NA engine to the turbo engine, on phillip island where its much more rewarding on engine power, the turbo switch gained me 4 seconds alone. The thing to consider in all of this is obviously what sort of compromise you are willing to take to get times down. Weight saving is by far the cheapest way to gain times that i have found, and tyres (suited to suspension and chassis) is the best once you have reached the stage of ful stripped, and pretty much maxed on power)

[tinkerbell]

my thoughts are that its ok to hard tune but the light tune is make the least amount of comprimises interms of comfort/driveability.

Once u get past the light mods you SEVERLY compromise driveability/comfort/etc etc.......

oh, so my B20VTEC example went from "light tune" to "light tune", with just more power...

[szymonsta]

thnx freakie.
has anyone found it necessary to change from the stock dc2R LSD? what are the reasons to modify this part? since i have no wheelspin/traction issues and turn-in seems very good just from tyre/suspension/alignment setting, what are the benefits in changing to an aftermarket mechanical LSD eg cusco rs 1.5way?

[Jingers]

oh, so my B20VTEC example went from "light tune" to "light tune", with just more power...

would u say ur b20vtec played up more then ur standard engine?

reliability wise would a person with 0 knowledge of the engine conversion suffer? a person that wants to drive it from a-b everyday

[tinkerbell]

ahhhh, mmmm, point taken!

but if i built it for someone else, then yes, they would happily drive form a-b everyday with no problems...