most turbo cars (and it seems like the BIG turbo ones are worse) have a big spike in power when boost hits....this spinning tires

integra_gsr98 wrote:
Drive a car that loses traction @ 5000 rpm in 3rd gear on the interstate and then you'll understand this.

i will have to take your word for it in things of this nature... especially since my car is awd and i'm still on the 14b. maybe someday i'll have a rwd with this ability

Traction loss comes from an instant gain in HP. Most turbos under WOT still lay into the HP pretty fuckin hard, laggy or not.

the whole thing about lag helping with traction i pulled from my reading of other sites/posts, likely from people that have little to no experience with high-hp fwd? as stated before, i don't really have a point of reference for losing traction on the interstate.
i do understand the point being made about power coming on very quickly with a turbo. i've seen many dyno graphs where power is fairly linear (i think nick's 530hp pull is a good example... can't recall perfectly), and several where power is much more exponential (13sec, 455hp k20 from some recent car magazine jumps to mind). i would expect the curve to be a bit more linear with lower compression, but i don't have quite enough experience (as you sub 12sec guys are quick to point out ;)) to know for sure.

out there wrote:
exactly! there's an additional 3mm per cylinder of static displacement (not sure if that's a proper way to state it).
so... if one used the right pistons to achieve compression of say... 7:1, then that would practically perfect.
7:1 would cause more lag, but that would be beneficial because you're fwd and you'll need that to get hooked up before the boost comes on. plus, with less compression, you should be able to run much more boost and make much more power

And off to school again...

Lag doesn't help traction, it just delays it. Drive a car that loses traction @ 5000 rpm in 3rd gear on the interstate and then you'll understand this.

Traction loss comes from an instant gain in HP. Most turbos under WOT still lay into the HP pretty fuckin hard, laggy or not.

...of course, you'd have to get the block sleeved to run as much boost as you would want so you could make much more power... and the cost of the crank would be unnecessarily high... not to mention the boring...
i'm sure i would figure something out if i kept working these things out long enough; however, i may not ever play with these things the way that my ideas suggest... so, just continue ignoring me until i can offer some sort of proof that my idea might work. i think that's a grand plan... but we seem to have proven that what i think isn't always the best solution

out there wrote:
exactly! there's an additional 3mm per cylinder of static displacement (not sure if that's a proper way to state it).
so... if one used the right pistons to achieve compression of say... 7:1, then that would practically perfect.
7:1 would cause more lag, but that would be beneficial because you're fwd and you'll need that to get hooked up before the boost comes on. plus, with less compression, you should be able to run much more boost and make much more power

If i were to run 7:1 CR i would have to run 10 psi to achieve stock horsepower. There is no logical reason to run that low on compression. The idea behind turbo is to avoid lag. Slicks will compensate for the traction not low compression. I'd have to run a T25 w 7:1 CR to even think of spool before rev limiter.

I'll put it this way. If i kept the stock 9.2:1 CR and say ran 10 psi, and then did your way of 7:1 CR i'd have to run say 20 psi to make the same power. Now in the overall peak power is going to drastically be reduced w/ a 7:1 CR.

Nick

out there wrote:
not what i'm saying at all. the stroke is still the same (b18 crank), the rod is just shorter, thus increasing the space between the top of the piston and the top of the block.
actually, i came up with this on my own by looking up the specs of b-series engines. i did read something in this territory about dsm blocks, but i have a meeting at 9... so i'll try to look it up later today.

Ok, even @ this rate you are reducing compression. By doing so you are going to lose power, so i guess im @ little lost @ what you're trying to say/accomplish here.

Nick

PSiedTSi wrote:
if you increase the space between the piston and the top of the block you are shortening the stroke and lowering compression....

If the crank is the same, the stroke doesn't change. It doesn't matter what length rod you use, it is still moving the same distance (stroke).

If all you change is to a shorter rod, only the compression has changed (lower).

PSI2HI wrote:
Time for you to retake Math class. 81(bore)x 89(stroke)=9.20:1 CR 1834cc(stock LS). Now w/ your theory by shortening the stroke 3mm we get 81(bore)x 86(stroke)= 8.92:1 CR, 1772cc (OUT THERE SPEC LS). Now if my theory is correct this idea sounds completely ASSANINE!!!!

not what i'm saying at all. the stroke is still the same (b18 crank), the rod is just shorter, thus increasing the space between the top of the piston and the top of the block.
actually, i came up with this on my own by looking up the specs of b-series engines. i did read something in this territory about dsm blocks, but i have a meeting at 9... so i'll try to look it up later today.

out there wrote:
the way i figure it, with b16 rods being 3mm shorter than ls rods, that leaves an extra 3mm of air at the top; essentially, this is increasing the compressed air/fuel mixture to 92mm (3 + 89 stroke) of the cylinder.
81mm (bore) x 89mm (stroke) = .458.6L/cylinder (1.834L)
81mm (bore) x 89mm (stroke) + 3mm (space at top) = .474.1L/cylinder (1.896L)
that's 3.5% more air than stock. i'm not saying that it's a drastic difference, and almost definitely wouldn't work with stock pistons (hence the comment in my previous post); but it would be a good idea to rebuild a turbo engine to increase the displacement and be stronger, right?

Quit reading the internet. The guy posting this is probably 10X dumber than the people reading it. The internet is NOT the best/onlyt place for information.

Time for you to retake Math class. 81(bore)x 89(stroke)=9.20:1 CR 1834cc(stock LS). Now w/ your theory by shortening the stroke 3mm we get 81(bore)x 86(stroke)= 8.92:1 CR, 1772cc (OUT THERE SPEC LS). Now if my theory is correct this idea sounds completely ASSANINE!!!!

Nick

out there wrote:
ok, correction. it would increase your displacement to 1.9... why don't you use these rods with some forged pistons in your latest turbo integra?
no rudeness intended, i'm sure you've done most of the brainwork before deciding to sell these... but it just looks like it would increase the output per stroke, thus increasing your tq, right?
correct me if i'm wrong on any of this.

Simplest answer here.....because i dont want to!! Im not worried about the internals of the motor right now, and if im going to tear into the motor im gonna make it worth my time.

B16's have a shorter stroke than a LS so idk where your getting these figures from. B16's have the short strokes for high rev's as the LS has the long stroke larger displacement.

Nick