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Discussion Starter #1
Hi i live in the UK and i have a ALmera GTI which uses the SR20D engine. I dont understand why you can only get 125 out of your sentra. I can get 150 out of mine but on a closed off road. My Limiter is at 7500. I dont see why you just get yourself a bottom end ECU and tune your engine for bottom end power. Then take your limiter off and get yourself a bottle of NOS 50 shot. But becareful not to blow a piston.
 

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neutral handling is cool
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Gotta second that face...Can you please rephrase that post? I don't think you define bottom end power the same way we do...bottom end power is between 1 and 4 on the Tach. The reason some of our sentras can only go 125 is that their may be a spec speed limiter/fuel cut off...although I don't know of one stock. Also, cops love catching us going 80 in the US, but they love catching us trying to go 150 even more...
 

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we're also talking about miles per hour, not km/h. another thing is that a stock sr20de can not pull a car to 150 mph. my 300zx strugles to do 145 mph.
 

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Discussion Starter #5
Ok ill rephrase it. Yeah i did mean in the lower revs. Between 1 and 4. I find that most of the time i need the power from 0-60. There must be a few different specs. I have a Euro SR20DE. Could there be any differences? I had 150 out of mine but i guess it might be the difference of where the limiter is. I have a freind who has the same as me. We have both had 150 MPH.
 

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I think Euro and Japanese Engines have 10:1 compression as opposed to the US 9.5:1. I don't know that our cars have limiters, but it's possible. It happens that for insurance and emissions regulations they change a lot of specs for different countries.
 

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Just from conversations with multiple people and reading other posts I've come to a couple of conclusions about what you're saying. There appears to be a couple of different schools of thought between western world cars and more 'eastern' (euro's not really eastern but for the purpose of this it might be easier to consider them this for the time being) as well as insurance, gas and driver reasons. It's a well known fact apparently that US gas is kind of crappy compared to most of the planet, someone mentioned that we have a high phosphorous content (think it was phosphorous) which causes catlyst problems during combustion as well as the fact that we have a typical max of 94 octane gas avaiable to the public although you can find 105+ octane on rare occasions throughout the US. The apparent result of that is to make a reliable engine run reliably in the US the manufacturer won't go above 11:1 to prevent the engine from blowing itself up from knocking. It might be obvious as well that given the high speed driving on roads in places like Germany with the autobahn getting from 60-100mph (don't know metric conversions for mph to kph, I'm just an ignorant american, lol) is ultimately more imporatant than going from 0-60 so power is placed at the top end instead of the bottom end which typically results in a higher top end, I'm not going into speed limiters on this really but because we have such strict 'you go to jail over 90 mph' laws there's no real need to let the car exceed 100mph in most cases and a governor typically results in cheaper insurance since the car can't get above a certain mph. Basically yeah, there are major variances in specs between euro versions of the same american cars. As far as fairgentleman's statement is concerned, I'd beg to differ on the top speed...there was a damn good reason why I did it but I got pulled over once for doing 135+ in a 92 Mazda Protege and it was still pulling hard at the time...believe me when I say, I was as shocked as you probably are in disbelief that that's true. There's a number of factors that can change a cars top end characteristics, hp is just one of them, gearing plays a big part too. A good example of apples to apples (with just a tranny difference) is the late '80's mustangs. A '89 Mustang GT 5.0 had an avg of about 7~ sec (according to Ford) 0-60 stock but topped out around 155ish, the exact same year and engine is in the '89 Mustang LX 5.0 but it's 0-60 was an avg 6~ sec but it topped around 120 mph with no governor. Those numbers aren't exact so if someone wants to jump all over me cause they're wrong then that's fine, but I know the differences are about right which is the point, heh.
 

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neutral handling is cool
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Wouldn't a mustang 5.0 engine will blow itself if it goes that fast...Not only is the resonance tuning ignored on those engines, but OHV engines can't breathe well enough at the RPM it would take to go that fast?
 
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Along with everything that has been said keep in mind also that the Sentra (stock) is drag limited to about 125 and NX2K (also stock but because of better aerodynamics) to about 135. Of course some people have said to have gone past this but then talk of spedos and tachs being off comes up.
 

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SR20D_GTI said:
I have a Euro SR20DE. Could there be any differences?
Yes there are differences. Euro-speced SR20DEs are closer to Japan-speced SR20DEs. They are "lighter" on emmision stuff and with a 10:1 compression rate.

I had 150 out of mine but i guess it might be the difference of where the limiter is. I have a freind who has the same as me. We have both had 150 MPH.
There is ABSOLUTELY NO CHANCE for a 143hp at the crank weighting close to 2500lbs and with a CD ~.30+ to hit 150mph!!!

Again there is ABSOLUTELY NO CHANCE to hit 150mph in our cars!!!!! (unless it is free-falling down a 2mile deep canyon!!!)

It is simple physics. With those parameters the absolute theoretical top speed is somewhere in the area of 133.5-136.5mph.

Your car (and your friend's car) have very optimistic speedometers.

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Chris
1992 Suny 2.0GTi
 

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Discussion Starter #11
I went out and tested my car to see what i could get out of it. Now this is a fact i had 140 MPH out of it. I had a friend in a supra cruising along side me and he says he was doing a 140 as well. I still had more cause i was sitting at around 7200 RPM.Then he put his foot down and left me. It is possible
 

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Discussion Starter #12
I went out and tested my car to see what i could get out of it. Now this is a fact i had 140 MPH out of it and still more left. I had a friend in a supra cruising along side me and he says he was doing a 140 as well. I still had more cause i was sitting at around 7200 RPM.Then he put his foot down and left me. It is possible
 

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Unless you are clocked on radar you can not get a accurate speed past about 90mph. What gear were you in when you were at 7200rpm? What are the gear ratios of your transmissions including the final drive ratio? What size tires are you running? If you hit 7200rpm in fifth gear with the same gearing as the USA spec transmission and with the same size tires then that is moving pretty well.
 

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Discussion Starter #14
I can do 120 in 4th gear and at that point i change up to 5th. I have 17" wheels so im probably doing more then that like i say i have had more then 140. I tell you what ill post a pic of my speedo and a bit of road and show you 140 +. Then will someone believe me?
 

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SR20D_GTI said:
I can do 120 in 4th gear and at that point i change up to 5th. I have 17" wheels so im probably doing more then that like i say i have had more then 140. I tell you what ill post a pic of my speedo and a bit of road and show you 140 +. Then will someone believe me?
I think you are taking this in the wrong way. No-one said your speedo does not show 140mph. It may even show 150, 160 or whatever for all I know.

What is simply stated by forum members is that there is a limit to the top speed of any car that is horsepower related and can be calculated by using simple physics and technical information from any car.

The calculation is rateher involved but it can be done. So, here is from www.pumaracing.co.uk , the horsepower vs. physically attainable speed for an average car:

(It assumes a car weighing 2500 lbs with driver, 21 square feet fA, 0.35 Cd and front wheel drive so transmission losses are 15% of the flywheel power which is VERY close to our cars and maybe a little optimistic since 2500lbs WITH driver is nowhere close to the truth).

SPEED(mph) FLYWHEEL POWER REQUIRED (hp)
100 _______________ 69
110 _______________ 90
120 ______________ 114
130 ______________ 143 *
140 ______________ 176
150 ______________ 215
160 ______________ 258
170 ______________ 307

Now, since our cars are close to the (*) in the table and 140 requires 176 crank hp, I simply stated that your speedo is rather optimistic.

Chris

PS. The site mentioned above is (in my opinion) the best resource you can find regarding crank vs. wheel hp relationships etc. I suggest forum members cosult it.
 

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Discussion Starter #16
Ok my speedo has 150 on the clock. I have had 140 + and i have 17" wheels. surley the top end speed of the car would be off cause of the different wheel size. 17" would make the actual speedo slower then the speed your doing
 

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hpro123 said:
Yes there are differences. Euro-speced SR20DEs are closer to Japan-speced SR20DEs. They are "lighter" on emmision stuff and with a 10:1 compression rate.

There is ABSOLUTELY NO CHANCE for a 143hp at the crank weighting close to 2500lbs and with a CD ~.30+ to hit 150mph!!!

Again there is ABSOLUTELY NO CHANCE to hit 150mph in our cars!!!!! (unless it is free-falling down a 2mile deep canyon!!!)

It is simple physics. With those parameters the absolute theoretical top speed is somewhere in the area of 133.5-136.5mph.

Your car (and your friend's car) have very optimistic speedometers.

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Chris
1992 Suny 2.0GTi
I know that my friend Kyle Davis and Ben Rockwell were clocked by radar going 150+ mph during the Silver State Classic race in Nevada in a NX2000 with simple bolt on mods.

There car makes about 145 to the wheels with only a header, UD Pulley, JWT ECU, Exhaust, CAI and JWT S3 cams.

Mike
 

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Discussion Starter #18
Ok hpro123 lets leave at this i will get you a picture of my speedo doing 140. I dont know when cause i aint gona risk my ass doing it. I know myself that my car will do 140+ MPH. Your stats show that it cant. Mayb my speedo is off but its off by a long way. And so are all my friends speedo's. Im gona check the web site and i do beleive what your saying.
 

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SR20D_GTI said:
Ok hpro123 lets leave at this i will get you a picture of my speedo doing 140.
I have seen MY OWN speedo often showing 230+ kmh. This is ~144mph.

I am simply saying that I highly doubt my stock car does 144 ACTUAL mph.

The only time I had the opportunity to actually radar-clock my car (working for a local car magazine way back in 1994 when it had 20K miles - and under unspecified weather conditions) it clocked at 215 Kmh = 133.6mph (average of 4 runs - 2 each on opposite directions of the same road strip) and 219kmh = 136mph best run.

Chris
 

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morepower2 said:
I know that my friend Kyle Davis and Ben Rockwell were clocked by radar going 150+ mph during the Silver State Classic race in Nevada in a NX2000 with simple bolt on mods.

There car makes about 145 to the wheels with only a header, UD Pulley, JWT ECU, Exhaust, CAI and JWT S3 cams.

Mike
Well Mike,

I had enjoyed reading their accounts very much last year but -if you want to be technical- they actually clocked 140mph since this was the limit in their chosen category.

In any case, the NX has a smaller frontal area than Sentras/Sunnys/Almeras and maybe this (plus their 172+ crank hp) may account for their top speed.

I will do an NX + Almera specific calc table and see what it gives.

Chris
 
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