Jump to content
SAU Community

Recommended Posts

Hey forum once again I call on the experts to assist me with a question I have. Car is a 95 gts-t, mods are 3.5" turbo back exhaust with split dump, pod filter, iridium plugs gapped at .7, ebc boosted up to 10 psi, and i just recently got on 98 ron fuel after using 95 for a year. Everything else stock and an afc neo but its not tuned. Neway, here is the prob got a gtech pro, and its the best thing to a dyno i have, i did a few runs and i noticed that I am having more power in second gear than throughout the entire third gear rev range. What could be causing this? Can neone tell me or give some opinion as to y second gear is reading more hp than the entire third gear. The reading was 222..6 hp at 5610 rpm in second gear and the highest hp in third was 218.1 at 5676 rpm. Thanks in advance for all help!!

Link to comment
https://www.sau.com.au/forums/topic/184226-more-horsepower-in-2nd-than-3rd-wtf/
Share on other sites

You should know but since I failed to mention it this is at wide open throttle, also I noticed boosting starts for me at 2-2500rpm and is not full on till like 4000rpm does this seem correct for stock turbo with the boost turned up to 10 psi

Hi,

As far as i know the G-techs measure the amount of pull aka g's, therefore in second gear it should appear slighty higher as its a shortrer ratio therefore giving it more pull as the gear is shorter and doesnt take as long to get through, But third is longer and takes a tad longer to go through the entire gear.

The last g-tech i had was useless, bought it just to compare, it told me i had 253HP in 3rd, but when i chucked it on the dyno was just over 300hp.

Best bet is to take your car to your local dyno shop and get a couple of power runs.

second gear = more suspension squat = gtech reads apprently larger acceleration forwards because of gravity

wind resistance = less net acceleration as well

most importantly, you're using a g-tech to measure a 2% difference and wondering why the discrepency is there. I'd be happy yo have a g-tech work that well at all.

hope that made sense.

second gear = more suspension squat = gtech reads apprently larger acceleration forwards because of gravity

wind resistance = less net acceleration as well

most importantly, you're using a g-tech to measure a 2% difference and wondering why the discrepency is there. I'd be happy yo have a g-tech work that well at all.

hope that made sense.

Yea I undersatnd what you are saying but shouldn't third read a higher horsepower figure seeing it is a more powerfull gear i mean 218 is the highest I got to redline? I figured you would get a higher horsepower readin in third seeing as when you go to a dyno thats the gear the would use to tune and get max hp out of.

more powerful gear??? wtf is that suppose to mean.. its a gear.. it only transmit power frmo the engine.. which is the same despite what gear ur in...

Gears are just a multiplier of torque in most cars from 1st to 3rd... 4th is usually a 1:1 ratio which is why dyno runs r done in 4th usually or the gear closest to to the 1:1 ratio.

2nd is usually like 2.5:1 which means that if ur shitbox makes 100hp @ engine, then ull have 2.5 times that coming out from the box. 3rd is lower still so it will register lower

u tryin it in 2nd or 3rd is just pointless. get to a real dyno and ull see how much u really make

Dynos dont use 3rd champ. and if a paticular shop does.. i wouldnt go there.. means theyre shitty dyno doesnt go past certain speeds = cheap bastards

Edited by Bumblebee
more powerful gear??? wtf is that suppose to mean.. its a gear.. it only transmit power frmo the engine.. which is the same despite what gear ur in...

Pardon my use of terms but I meant smaller ratio.

Gears are just a multiplier of torque in most cars from 1st to 3rd... 4th is usually a 1:1 ratio which is why dyno runs r done in 4th usually or the gear closest to to the 1:1 ratio.

2nd is usually like 2.5:1 which means that if ur shitbox makes 100hp @ engine, then ull have 2.5 times that coming out from the box. 3rd is lower still so it will register lower

Thanks for that bit of info

u tryin it in 2nd or 3rd is just pointless. get to a real dyno and ull see how much u really make

Dynos dont use 3rd champ. and if a paticular shop does.. i wouldnt go there.. means theyre shitty dyno doesnt go past certain speeds = cheap bastards

Another lesson learned, Cause I saw a few so called tuners over here tuning in third which they said third or fourth will b okand also one was road tuning a car in third as he didn't have access to a dyno

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I came here to note that is a zener diode too base on the info there. Based on that, I'd also be suspicious that replacing it, and it's likely to do the same. A lot of use cases will see it used as either voltage protection, or to create a cheap but relatively stable fixed voltage supply. That would mean it has seen more voltage than it should, and has gone into voltage melt down. If there is something else in the circuit dumping out higher than it should voltages, that needs to be found too. It's quite likely they're trying to use the Zener to limit the voltage that is hitting through to the transistor beside it, so what ever goes to the zener is likely a signal, and they're using the transistor in that circuit to amplify it. Especially as it seems they've also got a capacitor across the zener. Looks like there is meant to be something "noisy" to that zener, and what ever it was, had a melt down. Looking at that picture, it also looks like there's some solder joints that really need redoing, and it might be worth having the whole board properly inspected.  Unfortunately, without being able to stick a multimeter on it, and start tracing it all out, I'm pretty much at a loss now to help. I don't even believe I have a climate control board from an R33 around here to pull apart and see if any of the circuit appears similar to give some ideas.
    • Nah - but you won't find anything on dismantling the seats in any such thing anyway.
    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
×
×
  • Create New...