Increasing top speed?

[Hyper4mance2k]

From everything I have read, there is no stock limiter. The car is drag limited to 136 MPH at stock power. With my areo mods, stock ECU and bolt ons I have in theory, once or twice, may or may not have, on occasion, off public highways, in the middle of the desert, hypothetically, gone 137mph and the car was still pulling.

Header, catback, & K&N.

[Summerwolf]

Originally Posted by OkieSnuffBox

Why it's not hurting the engine and you can still get 30mpg on the highway?

Because it is effing annoying and you could theoretically get better mileage if it didn't have to rev so high......

[CoupedUpSubie]

Originally Posted by Summerwolf

Because it is effing annoying and you could theoretically get better mileage if it didn't have to rev so high......

Any gains in mileage seen at cruising speeds will be mostly offset by increased effort of taking off. Those that have gone with lower gears say they only lost 1-2 mpg at most IIRC. The bigger benefit of lower RPMs at cruising speed would be less exhaust noise while cruising.

[churchx]

Selling point of these cars is handling. NOT top speed, NOT cruise comfort or good sound insulation. Increasing something that is not their strength & purpose at expense of severely hurting THE purpose/strength of them makes me think that wrong car was bought. Even for twins MSRP there are faster ones, there are more comfortable/quieter ones. It's hard to find better handling ones at this price range (except Miata of course, but i doubt it's top speed or comfort being very high on list too).

[zooki]

The beauty of these cars is they're cheap enough that they can be modded however somebody want to mod them. AutoX? Yep. Drag racer? Yep. Bonneville flats salt liner? Sure, why not. Rocket Bunny cambered out parking lot crawler, yes sir. It kills me that some people think you can only build these cars a certain way, and only use parts that cost a certain amount.... Come on, I'm a hot rodder. Improvise, adapt, haul asss! 😃

[brn12345]

The way these cars are tuned from the factory make it very hard to achieve high top speed. Although there is no outright top speed limiter, the ecu starts to close the throttle as higher speeds are achieved. The following link is to testing I did last year on this very issue. You will notice in the data logs how the throttle physically closes.
http://www.ft86club.com/forums/showthread.php?t=58835

[stugray]

Originally Posted by Hyper4mance2k

From everything I have read, there is no stock limiter..

After my comment above I pulled out RomRaider and looked at a stock ROM.
Amaya was 100% correct:

Originally Posted by Amaya

The stock speed limiter is a soft limiter set at 137 and 140. The fuel cut speed limiter is set well over 200mph.

The soft limiter is set at 137 & 140.

[Summerwolf]

Originally Posted by CoupedUpSubie

Any gains in mileage seen at cruising speeds will be mostly offset by increased effort of taking off. Those that have gone with lower gears say they only lost 1-2 mpg at most IIRC. The bigger benefit of lower RPMs at cruising speed would be less exhaust noise while cruising.

If the Overdrive gear was steeper there would be no extra effort in taking off.

[OkieSnuffBox]

Originally Posted by Summerwolf

Because it is effing annoying and you could theoretically get better mileage if it didn't have to rev so high......

And the lower revs would require more throttle input to maintain the same speed.


It's really not that big of a difference either way.


Turn your stereo up, or put a nice exhaust on the car.

[Summerwolf]

Because in sixth maintaining cruise at 70-75 requires a ton of throttle input right?

You're right, it really isn't that big of a deal, I was saying in an ideal situation.

I haven't even seen rear gears available besides higher ratios, and no trans gearing changes. It seems to me a lower ratio rear with as many turbo vehicles are out there would be almost common.

[Hyper4mance2k]

Originally Posted by stugray

After my comment above I pulled out RomRaider and looked at a stock ROM.
Amaya was 100% correct:


The soft limiter is set at 137 & 140.

So what is a soft limiter, spark cut? Normally that's what soft limiters are referred to as.

[churchx]

Imho spark cut would result to too quirky 'cut' at that speed. And why would one use it, if throttle is drive by wire, and ECU simply may set it to position it needs to not go over limit? Think of it as high-speed cruise control, lol

[steve99]

Originally Posted by Hyper4mance2k

So what is a soft limiter, spark cut? Normally that's what soft limiters are referred to as.

it looks like their is three "limiters"

Throttle "limiter" set to close throttle plate partially in at 140mph ie close throttle till 137 mph then allows throttle to open futher again

Fuel cut limiting at over 200mph , unlikely to ever hit that one stock


RPM limiter stock at 7400 unlikely to hit that in top gear on stock car.

all can be adjusted via tune tables.

[Hyper4mance2k]

Originally Posted by churchx

Imho spark cut would result to too quirky 'cut' at that speed. And why would one use it, if throttle is drive by wire, and ECU simply may set it to position it needs to not go over limit? Think of it as high-speed cruise control, lol

That was my point. Soft limiters are spark cut. So it sound's like we're ECU limited to 140 with the stock tune.