Transplanted engine vs Speedometer

[drummydrew]

good afternoon all, this question struck me moments ago:

if a car's engine is transplanted from a lower 1.5 to a 1.8 one, how will it affect the accuracy of the meter reading on RPM and speedometer?

for example my car is satria 1.5 which has a 6500rpm red line on meter, but the 4g93 engine spec reads it has a red line of 7500rpm. how do i know if im getting an accurate reading?

 

[sanekit]

If use 4g93 meter sure accurate right? :hmmmm:

 

[drummydrew]

im using a 4g93, but the instrument panel is a 4g15 one

 

[AD_EG]

normally depends on the sensors... when you change the engine... comes with gearbox...that gearbox got its own speedo. 4g15 and 4g93 dont share the same wiring..so ur mech surely install with ecu wiring and gb as well..so even if ur meter ori...he would have connected that speedo to ur gearbox...so should be quite accurate.

but for rpm reading...that meter wont be so accurate in terms of redline... the rpm will be accurate +- 100 lets say... but since you know ur new plant is 7.5k ....you can just ignore ur redline warning at 6500.. and rev it to 7500 if you want

in terms of accuracy it should be the same.

 

[drummydrew]

normally depends on the sensors... when you change the engine... comes with gearbox...that gearbox got its own speedo. 4g15 and 4g93 dont share the same wiring..so ur mech surely install with ecu wiring and gb as well..so even if ur meter ori...he would have connected that speedo to ur gearbox...so should be quite accurate.

but for rpm reading...that meter wont be so accurate in terms of redline... the rpm will be accurate +- 100 lets say... but since you know ur new plant is 7.5k ....you can just ignore ur redline warning at 6500.. and rev it to 7500 if you want

in terms of accuracy it should be the same.

thank you so much for clearing it up for me! so i suppose its safe for me to try take the rev there if its reading properly maybe replacing to a gti panel would cure my ocd hehe

 

[vr2turbo]

Anyway, you don't red line all the time or do you?.....:hmmmm:

 

[drummydrew]

Anyway, you don't red line all the time or do you?.....:hmmmm:

hahaha in fact im hardly near the redline, comes with a high cost

 

[RENESIS VIII]

im using a 4g93, but the instrument panel is a 4g15 one

4G15 RPM panel max out at 8000rpm which I think is still fine for your 7500rpm red line in 4G93. Imagine 4G92 MIVEC but using 4G15 RPM panel. Red line is at 8500 I think.

 

[vr2turbo]

hahaha in fact im hardly near the redline, comes with a high cost

I hardly red line too, but like bro. AD_EG said if out + - 100 still okay mah!

 

[drummydrew]

4G15 RPM panel max out at 8000rpm which I think is still fine for your 7500rpm red line in 4G93. Imagine 4G92 MIVEC but using 4G15 RPM panel. Red line is at 8500 I think.

dayum, it'll be interesting n scary to see it pushing pass the rpm meter lol!

I hardly red line too, but like bro. AD_EG said if out + - 100 still okay mah!

glad to know that it's not far off, good for reference in case im feeling heavy footed

 

[vr2turbo]

dayum, it'll be interesting n scary to see it pushing pass the rpm meter lol!

Well, if you hear your engine screaming, faster lift off your right foot......lol

 

[AD_EG]

but generally hitting the redline dont mean anything without checking your power curve on the dyno.. so dont be revving it at redline thinking you're making power all the way up...always follow the feel and sound of the engine...after much spirited driving on your engine, you can feel when is the right time to shift.. and it should be earlier then the redline... usually after some serious mods to the intake, exhaust, fuelling, ecu, cam settings, and nice retune you might be able to make power all the way to redline. better yet, mivec head. hehe

 

[vr2turbo]

but generally hitting the redline dont mean anything without checking your power curve on the dyno.. so dont be revving it at redline thinking you're making power all the way up...always follow the feel and sound of the engine...after much spirited driving on your engine, you can feel when is the right time to shift.. and it should be earlier then the redline... usually after some serious mods to the intake, exhaust, fuelling, ecu, cam settings, and nice retune you might be able to make power all the way to redline. better yet, mivec head. hehe

I prefer to play with torque, because after max torque don't feel the pull any more.....lol

 

[drummydrew]

but generally hitting the redline dont mean anything without checking your power curve on the dyno.. so dont be revving it at redline thinking you're making power all the way up...always follow the feel and sound of the engine...after much spirited driving on your engine, you can feel when is the right time to shift.. and it should be earlier then the redline... usually after some serious mods to the intake, exhaust, fuelling, ecu, cam settings, and nice retune you might be able to make power all the way to redline. better yet, mivec head. hehe

yes you're so right! i really cannot be sure until its put on a dyno for proper statistics. since i bought the car second hand, i have been doing minor fix-ups - replacing faulty compressor, fan belt, battery, plug cables and tires. it'll take some effort for me before getting to a proper tune up

another question though since we're discussing revving. i recently drove my car back n forth from penang, realized that there's a grinding sound whenever i released throttle during the highway run. any idea what could have caused it? sounds like its coming from the front of passenger seat, under the hood ..

 

[lsm1991]

yes you're so right! i really cannot be sure until its put on a dyno for proper statistics. since i bought the car second hand, i have been doing minor fix-ups - replacing faulty compressor, fan belt, battery, plug cables and tires. it'll take some effort for me before getting to a proper tune up

another question though since we're discussing revving. i recently drove my car back n forth from penang, realized that there's a grinding sound whenever i released throttle during the highway run. any idea what could have caused it? sounds like its coming from the front of passenger seat, under the hood ..

ouhh... this sounds..... very much like my issue......
1)tekan accelerator no sound can be heard (but mech said actually there was a some, very slight grinding sounds if u went very close)
2)tekan and hold rpms up, no sound
3)when rpms drop, there was a grinding sound (im my case it was pretty loud, very audible from in the car)
4)sound came from the belt area
5)sounds were not from drivetrain since it was present when testing in idle
6)interesting notes, sound only occurs when the car warmed up (my case, anywhere pass 70 deg)

if that sounds similar... (and no 4 sounds right) check the bearings, could be one of the bearings going bad.... start with the outer most belts 1st, slowly remove 1 by 1, trial and error style....