boostedrotor

hey no cab.....chris (rp) was telling me a properly tuned t-78 will out perform a gt35/40 .....

TYSON

I see your point RICE, but wouldn't a heavy hitting turbo coming on full tilt at 4500 RPM be just as upsetting to the chassis? Looking at some of the dyno charts posted for turbos like the T78 shows horsepower rising nearly vertical around midrange RPM. If you don't have your car pointing relatively straight, you might put it sideways. If you're straightened out, you'll likely spin the tires anyway. I'd rather have power that comes on a little earlier, myself, at not so steep an angle. Rotaries don't build a lot of power down low anyway, but having the turbo come on hard at the same time the engine starts to flow well can upset the chassis in a corner as well, wouldn't it?

The best way to test would be a back to back comparison. Same driver, two cars, same course. Nocab and Vosko are itching to do it, so why don't you guys try a track with some corners?

Even better test would be same car, same driver, a quick turbo swap. The E11 has two map sets.

vosko

iTrader: (4)

i road raced once. plan on going two times next year for mazdadrivers

RICE RACING

That is why turbo cars suck ***

The power delivery when tied in to boost build up is kinda exponential to turbine speed, it just depends @ what rpm range it comes in at as to how much of a problem it will present.

I know I hated my hybrid, as it was hard to feed in the power, though now the same is true of the larger turbine spec except that the traction problems happen once the car is straightened up

TYSON

Exactly
Hmm, I'm just starting this corner, but I better step on it now or that Viper in the mirror will run me over in the first 200 feet of the straightaway

RICE RACING

Tyson, that is why things like traction control are a "god send" to high HP turbo cars, especially in road racing as you guys call it.

It is just too hard to use the power you got wtih normal size tires that are not full racing slicks, especially with the characteristics of power delivery on a turbo charged car, it is very hard to modualte the throttle as you can in a n/a car to get a good balance cause the turbine has a mind of it's own once it gets up to speed

I am looking into the racelogic unit to make my car more drivable and faster without resorting to 12" wide soft compound slick racing tires and a soft rear suspension set up. Seems to be the best solution so far, ideal for guys who are into street racing I would imagine, but realy would add a great deal of saftey to a vehicle which would other wise be quite dangerous in the wrong hands even in ideal conditions.

Bit of topic, sorry about that

milkman2k52

Actually boost threshold is the rpms at which a turbo starts to make useful boost. Like when people say the GT3540 make full boost by 3400 rpms or whatnot, that is boost threshold. Lag is the transition from vacuum to positive boost pressure. It is directly related to the rotating mass of the turbine/compressor (i.e., how big they are) and the efficiency of the exhaust system. Things start getting confused when one person says the T-78 is laggy and another responds by saying it has full boost by 4k rpms, because those two are _not_ related.

KevinK2

I've used a similar test to compare FD set-ups. Can't just say mash it, since u could be initially producing some boost before the TB, even with vac at the manifold.

A good comparitive 'time to 10 psi' test would be 3rd gear, flat road, establish steady speed a few secs, then foot off pedal for 2 secs min, then at test rpm mash it, and count secs to 10 psi. May have to overspeed initially to drop to correct rpm in 2 secs. Test at 4k, 4500, 5k, 5.5k .... whatever.

This will indicate response among diff singles. If monster won't hit 10 psi till 5k, so what. But some test numbers may help guide someone looking for some lower rpm roll on power on a reliable single, and not just max performance in race conditions.

boostedrotor

hmmmm, ok, i think, yep, my head is going pop......i just want to build an all around bad *** car, if i have to deal with some lag, then so be it, can't you just stay in a more useful rpm range then.......