wondering....

why do people swap in the ls/rs engine instead of the gsr engine (sorry bout not puttin down the engine codes....)?
just wondering since for the gsr engine...start off with more hp and torque when people start modifying their engines....so why do people swap in a lower model engine that has less hp & torque?

don't know... may have to do with boost/compression.

[Violent Apathy]

Heard something about not wanting the GS-Rs VTEC. Also heard that LS/RS were better for boosting, just what I heard, i don't know.

[2ndGenTeg]

Common misconception: GSRs (B18C) make more power than the LS/RS (B18A/B), period.

B18Cs have 1797cc of displacement. B18A/B has 1834cc of displacement. The B18C is slightly destroked to make a better rod ratio in the name of higher revving, needed for VTEC to be effective. As a result, the B18A/B actually puts out a little more torque in the pre-VTEC part of the power band. However, the real advantage of the B18C over the B18A/B is the high redline, not VTEC. If the B18A/B had the same redline as the B18C and continued its same torque curve up to redline, it would end up with 169 factory rated horsepower, just 11 behind its VTEC cousin.

Also, as mentioned before, the B18A/B has more displacement. This means better low-end torque, and also better boosting. The B18A/B remains a favorite for FI applications because power increases exponentially with displacement.

VTEC seems to have a cult following, but nobody really takes the time to understand how it works, why it works, and the sacrifices made in the engine to make it work.

Nicely put!! I really have nothing to add to that but the fact that the gsr engine is more persued for swaps there for a higher cost while the B18B is a cheaper engine to begin with it! just my lil bit of a dolla

Originally posted by 2ndGenTeg
Common misconception: GSRs (B18C) make more power than the LS/RS (B18A/B), period.

B18Cs have 1797cc of displacement. B18A/B has 1834cc of displacement. The B18C is slightly destroked to make a better rod ratio in the name of higher revving, needed for VTEC to be effective. As a result, the B18A/B actually puts out a little more torque in the pre-VTEC part of the power band. However, the real advantage of the B18C over the B18A/B is the high redline, not VTEC. If the B18A/B had the same redline as the B18C and continued its same torque curve up to redline, it would end up with 169 factory rated horsepower, just 11 behind its VTEC cousin.

Also, as mentioned before, the B18A/B has more displacement. This means better low-end torque, and also better boosting. The B18A/B remains a favorite for FI applications because power increases exponentially with displacement.

VTEC seems to have a cult following, but nobody really takes the time to understand how it works, why it works, and the sacrifices made in the engine to make it work.

[C's 94 InTeGrA]

Ls non vtecs i hear are very easy to put a nice trubo on than a regurlar vtec ones.. i think thas true

[ebpda9]

so is the b18a/b a vtec ? i'm asking cause in my brother car i can't see any vtec badge on the headcover, or anywhere on the car.

[C's 94 InTeGrA]

well it would say DOHC Vtec on the valve cover and it woulkd have an emblem on the rigth side under the tail light if it was a vtec

Originally posted by hondaman-iac
so is the b18a/b a vtec ? i'm asking cause in my brother car i can't see any vtec badge on the headcover, or anywhere on the car.

nope...

[ebpda9]

well i guess i can buy one and stick it to the car and make it a fast vtec just spamming

One other thing to consider is the compression ratio of the B18A/B vs. B18C1/5...

Volumetric efficiency(pretty sure that's the correct term) is an indicator of output per liter(hp/liter). The higher the volumetric efficiency, the more power cranked out of any given engine. Supercharging/turbofying/nitrous-ing(?) and increasing compression increase volumetric efficiency. Increasing compression "squishes" the incoming mixture more. Forced induction(and nitrous too) cram more O2/fuel mixture into the cylinders. Any of these actions raise cylinder pressures... which increases temperatures and can cause detonation(when the fuel mixture "lights off" before the spark plug fires).

In the case of the B18A/B, the lower compression ratio allows higher boost levels than with the already high compression B18C1/5. The GS-R engine(C1) will take more boost than a Type R(C5) because of the same reason.

The following might not make sense... but anyways:
Atmospheric pressure is around 14psi... on any boost gauge, the "zero" reading is actually 14 psi(but it's zero relative to the ambient air). SO! Adding boost can be seen as going above the 14psi which means that if a naturally aspirated engine makes 350 hp, the same motor at 14psi of boost(28psi now) will (theoretically) make 700hp. The limiting factor is detonation(also of note: piston strength and material, rod strength, umm... head gasket construction, head-bolt locations, to name a few, also the higher you try to boost, the hotter the intake air gets which robs power)

Pah! I'm long-winded. I still love my GS-R but I'm putting too many miles on it... damn...

Common misconception: GSRs (B18C) make more power than the LS/RS (B18A/B), period.

B18Cs have 1797cc of displacement. B18A/B has 1834cc of displacement. <snip>