I don't think this topic has been covered before.

For those of you with FI, (TT, or SC or Single Turbo) and have your ECU tweaked to remove the 155mph top speed limiter, what is the top speed or fastest speed did you guys manage to pull off?

I'm not a 1/4 mile drag racing guy, but more of an highway high-speed racing guy, so I focus on top end speed & acceleration (over 60-200mph or whatever the can can make.) rather than 0-100mph or so.

With my Z, I only managed to 158mph at digital speedometer, (Engine mod: Intake, Exhaust) and it was somewhere at 5500rpm range at 6th gear. Say, if you have TS reflash with raised rev limiter up to 7200rpm, what would be the Max speed at that rpm range? I know it's impossible to reach it without siginificant power increase, weight reduction, or change in aerodynamics to improve drag coefficient, but I wanna see what FI Z in real life is capable of. (Not one of those Japanese Tuner Demo Cars, like Option Stream Z.)

Moderately modified E46 M3 can reach up to 180mph. (With ECU tune) And I don't see a reason 400whp Z can't reach that speed if gearing allows to do so.

 

I don't think many of us do that. Even with forged internals there is an inherent risk to the engine with maintaining 7000+ rpm for an extended period of time. It is just something the car was not designed for.

Personally, I haven't gone faster than 110; I just get there very quickly .

 

I haven't went over 143mph yet and I don't think I want to go over. But, I'm also interested in the answer.

 

https://my350z.com/forum/engine-and-drivetrain/104669-m-p-h-ts-flash-top-speed.html

 

I dont think it is a matter of FI or NA but more of gearing and drag, the FI will just there quicker

If you use some of the web calculators with the MT gearing top speed is around 180, but if you swap it out with the AT rear end you should be around 190.

 

I have had the digital gauge at 165 and it was there for a while so I could have been going faster than that. The car handles unbelievable at that speed. I have the Greddy e-manage and tt with a few minor transmission mods.

 

Wow, spazilot went up to 183mph on GPS? It probably means that he was going like 190mph on speedo (although ours have only up to 160) since speedometers are about 5-10% off at high speeds depending on cars.
I won't say it's a smart thing to do in public roads, but heck, it'll be really cool to break 190mph mark or perhaps 200mph. (300km/h)

 

didn't phunk say he hit 180+
i've gone 145..then again i don't have a reflash

 

i have not yet gone 180. 170 max with sustained 150-165 for about 20 miles. Highly recommend an oil cooler, this is probably what caused the slight wear on my rod bearings, oil was at 300 degrees.

Ill show you guys what 200 looks like this year Already got the video planned for that one.

 

You putting in an AT rear? I thought the 6mt even with the Technosquare rev limit would "only" do 184 or so. BTW, since you brought it up, does an oil cooler work all the time? Or just after the oil has reached a set temperature does it come on? Im asking because Im wondering if you can run an oil cooler if you dont always drive your car hard or in hot weather....tia.

 

i have been considering the AT rear but it is not planned just yet.

My car runs on the FCON, I can put the rev limiter where I want and my engine is built enough that I can rev it up to 9000 if I thought the oil pump would stay together and/or not cavitate.

A quality oil cooler adapter will have a built in thermostat so that oil is only sent to the cooler once it reaches operating temp. This way it doesnt take all day for the oil to get up to normal temp.

 

OMG.. 300 degrees?! Yeah.. Oil cooler would be a must if you go FI. (along with Koyo radiator)

Definitely show us when you reach 200mph. I wonder if anyone makes 200mph speedometer for US spec Z. (I know Nismo has one for JDM up to 320km I think? but none for US mph scale.)

So.. what do we need to break that magical 200mph barrier?

Hmm.. SGP built short block with APS TT and HKS F-Con Vpro.. Killer combo.. only if I hit a lottery.. Oil cooler, big radiator, thermostat to keep the car cool, GPS to measure accurate speed, a set of good tires that can endure such speed, and a coffee bench made of CF for added downforce. Oh, and a good radar detector, I mean a VERY good one. (Balentine V1?) With empty, long-straight highway with recently paved road surface.

What tire choices do we have for shooting maximum speed? I think my Toyo's are YR-rated, up to what speed is it good for? Are there any tires that can hold more than 200mph? Blowing up the tire at such a speed won't be a pleasant experience at all.

 

Lol I forgot you had the FCON Gracias for the oil cooler info...what temperature would most quality oil coolers activate at ?

 

good question.

 

This is an extrapolation, based on information I found on Stillen's website...

Typical [uncooled] oil temps on a 300ZXTT are 225 degrees F. The addition of an oil cooler reduces operating oil temps to "an optimal 185 degrees F." I am guessing normal operating temps on an F/I VQ35DE would be about 225 degrees F. [or warmer] unless an oversize, ribbed oil pan is in place. An oversized radiator may [at least indirectly] help keep oil temps down, too.

Can you buy oil cooler kits with thermostatically controlled diverter valves? If so, can they be set to actuate at somewhere around, oh, 180 degrees F.? If so, then engine oil would warm up from a cold start without taking all day. Once the oil reached a temp of 180 degrees F., the valve would actuate, diverting engine oil to the cooler. A diverter valve thermostatically set to 180 degrees F. would probably keep operating oil temps down around 185-195 degrees F., without cycling repeatedly while under operation.

Does that sound about right???