JZA70 Time Attack Track and Street

[1jz-Rolla]

Oh That's gotta hurt. Surprisingly and unfortunately, it seems fairly common to get BS advice to go down the wrong path with ECUs/wiring/tuning, which really sucks, given the time and money involved! You seem to be staying pretty calm about it dude


I wouldn't stress too much about 105 degrees on the dyno. They are a hot running motor in the first place (92 degrees) and you won't boil the fluid at 105 if your cooling system is in good working order - i.e: under pressure and with a decent additive. Mine in the Corolla sat happily at 102 degrees for extended periods on the circuit. If you're worried for track work, make sure all of the air entering the front of the car is being forced through the radiator core - use baffle plates etc to guide the airflow if you need to, screen the cores between the rad & air-con condenser with foam tape, ensure the undertray is fitted between the rad support and engine subframe, etc. Fans won't do much for you at speed on the circuit, so using all of the available air at the front of the car is your best way to efficiently shed heat.

Cheers
Phil

 

[LordDigital]

ok, so the brembo F50 is a significantly better caliper than the wilwood superlite 4? this is what I thought and probably why the prices are so different. In regards to my setup, ABS has been removed and I probably will add a proportioning valve in the future if I have issues with the bias.

That is correct F50 is a lot better than the superlite ,price difference between the two says it all

What master cylinder are you planing on using on "No ABS" setup? Keep in mind that toyota homolagated part for Group a had TypeA t type E master cylinders ,running in twin configuration starting from IIRC 18mm. I found brake modulation to be impossible with no ABS on my 1 and 1/8 master cylinder...

BTW TRD homolagated calipers look very similar to F50 ,possibly an early derivitive. Two pistons design with 44.5 & 41.3 pistons (my big bore F50 are 44/41mm)

 

[josbeat]

I fixed mine with miss problems with the HKS twin DLi
I think the supra igniter is powerfull than the SH61 but removing the MUX system is nice to control the timing correctly with the AEM

do you have the problems over 15 PSI ??

 

[josbeat]

about the brakes I recomend for the front the last kit I bought with floating disc , is the PB brakes kits , good price and good quality
the callipers are a copy of an AP Racing ones on a radial mounts so it is posible to use a big variety of pads compound and about the disc they are a copy of a AP racing disc floating and they are a rotors interchangeable!! 16 holes rotors

at the back I have the arizona kit with out parking brake (15 kg less) now it is a hydraulic parking brake system , good kit, it move the calliper to the other side and also very similar to a kit on the FIA book

 

[1jz-Rolla]

I dont have a part number sorry mate but when I called they said 2004-2008 is all the same for RDA. They just drill two stud patterns. I remember you saying something about different rotor hat heights though but from what the guys told me there was only one part no. I went through Car Parts Plus here in Adelaide which were the cheapest in the country. Phone no. is (08) 8326 0377. Wouldnt hurt to give them a call and clarify and even ask for a price on shipping to ACT.

Let me know how you go...

Must be a sign.... one of the ebay Aus sellers that I watch listed the 2004-08 STi rotors last night (RDA branded) for $144 a pair (plain) or $244 pair slotted. Done and dusted

This rear brake conversion will be a lot cheaper than my front F40/Biot ones were

Cheers
Phil

 

[spiller]

That is correct F50 is a lot better than the superlite ,price difference between the two says it all

What master cylinder are you planing on using on "No ABS" setup? Keep in mind that toyota homolagated part for Group a had TypeA t type E master cylinders ,running in twin configuration starting from IIRC 18mm. I found brake modulation to be impossible with no ABS on my 1 and 1/8 master cylinder...

BTW TRD homolagated calipers look very similar to F50 ,possibly an early derivitive. Two pistons design with 44.5 & 41.3 pistons (my big bore F50 are 44/41mm)

I actually just purchased a brand new OEM non-ABS master cylinder that I was going to use. Is that the 1 and 1/8 size that you are referring to mate? I havent been happy with the pedal feel AT ALL since I got the car but figured id bypass the booster and go un-assisted if modulation is an issue at the track. I remember reading in your thread that you were using a larger MC from a hilux or something? Care to shed any light on what I should be using?

 

[spiller]

I fixed mine with miss problems with the HKS twin DLi
I think the supra igniter is powerfull than the SH61 but removing the MUX system is nice to control the timing correctly with the AEM

do you have the problems over 15 PSI ??

I have been running about 18psi since the car was first tuned 2 years ago. The issue of no spark was apparently because the fool who wired in my haltech module ignitor (which was not needed) used a loom designed to be mated with the haltech CDI. That job cost me over $1500 and actually made matters worse! I agree, the standard 1JZ and 2JZ ignitors are extremely reliable and do not need to be upgraded in most instances. Many people making enough spark for 400rwkw at 20-25psi.

Phil: yeah im trying not to get too angry, it has happened over a longer period of time which I think helps dissipate the pain lol. thats a good score with the brake rotors indeed! With my cooling set up, i have a JAR radiator and ran a very thorough acid flush through the system about 18 months ago which got is squeaky clean. The car has not been used much since then but has had toyota red coolant in it. When I get it back i will flush it again, put some fresh stuff in there and run some water wetter too to see if that helps. You're right about cooling dynamics too, all of my undertrays and side panels are missing but I have some material here that I am going to make a front splitter out of. Ill box the sides in too like you mentioned. If all of that fails ill put a better radiator in.

 

[1jz-Rolla]

oh......... I didn't know it was a JAR special

If it worries you to have that radiator, with the Aussie dollar doing fairly well, the reputable Koyo radiators are a good option. I plan to grab one soon.

 

[spiller]

Yeah I'm not too fond of it and certainly wouldnt have put it in the car if it was my choice. The car has never run cool in my ownership. Depending on how much the koyo ends up landed, perhaps I will just bite the bullet. Let me know if you find a good deal.

 

[josbeat]

mate do you have pictures of the front upper arm?

 

[spiller]

Hey Jose dont have any pics right now but I will take some tonight or tomorrow and post them up. They are made by beech performance on this forum, they look pretty heavy duty!

 

[LordDigital]

mate do you have pictures of the front upper arm?

Some pics are available here: http://www.supramania.com/forums/showthread.php?151081-Adjustable-front-upper-control-arms

These are similar to FIA/JAF UPC Type C for MA70 (in the Fia book page 43). Only disadvantage is that adjusting the camber/caster on the track will be difficult because it will require removing the arm from the sub-frame ,thus I would not call them the best choice for enthusiasts...

BTW I have a few pics of the Benami Supras UPC and they were NOT ADJUSTABLE , basically variation of the FIA/JAF TypeE two-peace arm supposedly manufactured by Specfab UK. I guess that LCA adjustability was the better choice after all.

 

[josbeat]

my LCA give me a max of -1,5 degrees will it be fantastic if we can get more from tthe LCA but I am afraid to remove to much material from the LCA holes
I have a quote from beech, I know those but I want to see if those fitted get better angle than the stock ones with the car lowered

 

[HMNGSupraMKIII]

car looks nice

 

[1jz-Rolla]

I've got the Beech upper arms fitted to mine, it's a much better option than running a longer LCA in my opinion, as it reduces the track rather than narrows it, which means more aggressive wheel fitment is possible also without scrubbing the guards (and there's plenty of clearance on the inside).

Currently i've got 2.5 degrees neg camber with the OEM LCA's set to MINIMUM camber at the eccentric bolt, and still have adjustment left at the top Beech arm. So the scope for big camber is rediculous.

Sorry to get a bit OT Spiller


Cheers
Phil

 

[LordDigital]

I've got the Beech upper arms fitted to mine, it's a much better option than running a longer LCA in my opinion, as it reduces the track rather than narrows it, which means more aggressive wheel fitment is possible also without scrubbing the guards (and there's plenty of clearance on the inside).

Currently i've got 2.5 degrees neg camber with the OEM LCA's set to MINIMUM camber at the eccentric bolt, and still have adjustment left at the top Beech arm. So the scope for big camber is rediculous.

Sorry to get a bit OT Spiller


Cheers
Phil

MA70 track is far from ideal ,if event regulations are not limiting the fenders - adding flares or going A1 fenders is absolutely the way to go for better handling. Also if you set your LCAs at a minimum camber on the eccentrics - what is your caster? Caster is far more important than static camber - GroupA cars had as much as 10 degrees of that ,which is the MK3 best best kept setup secret (shhh don't tell anyone)

 

[1jz-Rolla]

That seems to be a highly debatable point regarding the 10 degrees caster run "back in the day"....... Though I agree in concept that most track cars respond well to an approach where the maximum caster achievable is run.

There are almost no events over here that cater for our cars, so class regulations are of little concern really. The events that would be limiting are way out of the average budget to participate in (Targa Tasmania for example).

The Beech arms allow further caster adjustment through independent settings at the front & rear heim joints, though i've not experimented with it at this stage (they are set to equal length for now). I just checked my wheel alignment settings both before and after fitment of the upper arms, as follows:

Before: less than 1 degree camber
8 degrees caster

After: 2.5 degrees camber
8 degrees caster

 

[spiller]

This is a juicy topic and I was just thinking about all of this on the way home from the workshop (they are just perfecting the cold start btw).

How much camber did the group A cars run at the front? John Smith mentioned something about 5.5deg of caster which is far from 10 so that's interesting. With the beech arms, I was planning on maxing them out so they're as short as possible and then having the wheel aligner fine tune the LCA settings. Is this a bad idea?

In regards to rear arms, I have the full set from beach but am reluctant to fit them all for fear of "heim maintenance" in case I feel like streeting the car a times. Is it unnecessary to have adjustable LCA, toe and traction in the rear or should I just fit the LCAs themselves? I've heard people say there is quite a bit of adjustment with the stock rear end anyway but every aligner you speak with tells you a different story...

 

[1jz-Rolla]

Only issue with maxing out the upper arms (to the shortest setting) is that your minimum camber will be somewhere around neg 3.5 i'd estimate. If you're happy with this, then go nuts

There is quite a bit of adjustment scope in the rear with the OEM bars, I'd be keen on adjustable upper arms, and traction rods because:

- minimum camber on the rear at my ride height with OEM bars is still nearly 2 degrees negative
- stiffer traction rods "should" help to eliminate the axle hop that I get on hard launches

 

[spiller]

The traction rods are damn beefy compared to the OEM ones but id imagine you'd still have the axle tramp issue unless you do something about your rear subframe mounts - I have solid ones here to install. I also have them for the front too but im not sure if they're necessary, in fact im not even sure if the front subframe is "floating" type like the rear?

Phil, with your concerns about minimum rear camber, the beech adjustable LCAs would solve this issue, thus no need for the upper arms. The traction rod makes sense. The toe arm seems a bit unnecessary, I always thought square toe on the rear was the way to go but im a novice, for sure. Is there any benefit to having heim joints in the suspension other than for alignment purposes? Does their "stiffness" offer handling benefits?