Brakes Problem

[GT4_Rule]

Hey guys,

Sorry if this problem I'm asking about was adressed before, but I couldn't find one...

Anyways.

I've just came around the 694-day mark for the black edition of the race cars, and bought the Nissan RC92 (whatever they're called) at the early-'90's showroom. It has 5 gears, lightweight body, and a powerful engine, and its acceleration is fantastic. But even though I've equipped the car with racing brakes, the braking performance of that car is really disappointing. I don't know why, but my '99 Aston V8 Vantage w/o any body lightening does better. I mean, its a race car, and shouldn't it have excellent brakes that shed momentum from, for example, 350km/h in less time than other, production-car based racers (like Nismo 400R)? The same problem goes for the '02 Ford GT as well, with 810hp and a racing brake AND a brake controller. When I first drove the car after suping it up with all performance parts, I was shocked to find out that the brakes offered little feel (like as if there were no brakes at all while braking; no usual vibration of the controller or the pumping sort of feel of the brakes) and the brakes did little to slow the car down, even when fitted with performance brakes. I entered the Supercar festival in Professional Races in New York, w/6 laps, and oh boy, the GT was handful just to steer around the corners, let alone slow down! After the long straight, there is a corner with the Infiniti G35 billboard, and 1 out of the 6 laps I made a (almost) perfect turn. Othe times, I would simply crash right into it, head-on or from the side, because the brakes did virtually nothing to slow the car down. Is this just my setup problem, or is this car like this from the start? Thank you for any comments.

 

[FormulaGT]

Does sound a tad odd...
Have you got, say R3-5 tires equipped? Remember, tires stop the car, not the brakes. Racing brakes, from what i've read in the 'GT4 Brake' thread & from memory, seem to less powerful than than the brake controller ones. Also, with more mileage than a new car, the body & components of the car might be 'softer' than a new one perhaps. Have you applied the chassis refresh? If not, do so as the black cars have done s*** loads of miles! Hope this helps...

FormulaGT

 

[Dark Elite]

I agree with FormulaGT.

I think the GT is just, like that... I've never liked it, it's big and heavy with too much power in my opinion, and I've heard complaints about it's brakes before.

But, my R92CP has never given me any trouble as far as braking's concerned... In fact, I find it pull up pretty quickly for saying it's got all the power of Group C...

DE

 

[Boundary Layer]

have you changed any settings on the R92CP?

I think the only way you'll get any real help with this difficulty is if you post up your car settings. I was thinking to myself that you might have raised your spring rates and/or brake balance controller settings too high and the ABS was drastically cutting your braking force. But it's only a half-baked theory until we can see exactly what it is you're driving.

 

[Praetorian]

I'm not anywhere the tuning expert as Boundary Layer or others, but in my opinion the racing brakes seem to have little or no effect on ANY of the cars I fit them with. The real stopping power I think comes from the brake controller, which is usually default at 3/3 when purchased. Now 3/3 may be just fine for most cars of around 200bhp, but for the much faster sport or LMP cars this is nowhere near enough. If you are racing with 800+ bhp, try setting front and rear about 5 clicks from max. Higher front brakes if your car oversteers, higher rear if it understeers. (or is this backwards?)

Then test them! go to the Test Course practice, get your car up to 150mph or 200mph (or kph equivalent) and slam on the brakes until you come to a complete stop. then floor it and do it again, over and over until you've completed a lap. then go to the analyzer and write down your stopping times in each instance.

Then make some adjustments to your controller (+/- 2 clicks is good) and repeat the test using your same speed cutoff braking points. check the analyzer again to see if there is any difference in your overall stopping times from your previous test lap.

and of course I probably dont need to mention you should always do at least 80% of your braking before you enter a turn, or your car will invariably continue to keep going more or less straight under 100% braking power.

someone wrote a useful guide somewhere (I cant recall who or where, but its stickied) concening brakes & tire usage. The gist of it being your tires can usually only do one thing at a time - decelerating, accelerating, or turning. If you try and turn while braking or accellerating, the brake or gas will override your attempt at steering, and you will get understeer.

so test your brake settings, brake early, and try and use throttle control on exits (dont just mash it, pump it a bit while you gain traction)

Edit: It was Scaff's guide, a highly recommended read!
also I found that Scaff's testing showed that racing brakes, while having little effect on standard or sport tires, show a fairly marginal amount of help when used with Racing tires.

Another Edit: Also he points out quite logically that brakes dont stop the car, the tires do - for quicker stopping use softer (Stickier) tires. However, in a large amount of races we are restricted to using Sport tires, so just go as soft as you can go with them without having them overheat before the race is over.

 

[GT4_Rule]

OK

Thanks you all for your advice. I will clarify some points.

The GT is spanking new when I tested it, and it now has 130km on the odo. The braking takes forever, and with that I mean with a brake controller with front 5 and rear 3 setting. When I'm at Las Vegas drag strip and doing quarter mile, usually in other cars with similar power and weight it stops around when the bend begins (after setting the time for that run, of course) But with the GT in that setting, it seems like it takes a lot more than other cars to stop. It doesn't stop until about 200m to the end of the strip (or, in another words, a LOT of distance past the finish line). I still have the stock sports-medium tires, since the Supercar Festival does not accept racing tires.

For the R92CP, no, I did not change any settings on it. Just after racking up a few hundred kilometers (about 500) I gave it a rollcage, and it still brakes bad. I dunno, maybe I should give it a chassis refresher plan. Its unticked =( I will do that sometime later and will tell you guys if it made any difference.

Thank you all for the advice! All these advices gotta fix this problem, or at least I hope it does.