If you are not a streeter, you can skip right over this post. But
if you are a streeter, then,in my experience;
Having fun with a streeter doesn't take a lot of motor. But
With a stick-car,the engine is locked to the speed,
and so,having the right gear, at the right time, and having traction are far more important, IMO, than absolute power, at some way-up-there rpm, that you don't get to until 40 or more mph..There's a lot to be said for bottom end engine torque, or TM, (Torque Multiplication). 340 hp with iron heads is a pretty good number to have fun with. But Ima thinking those 3.23s gotta go; they just lock your manual trans equipped 340 into an operating range that she may be a little unhappy at, especially once you get into second gear.
>For example, 30 mph in 1.92 second with 27s is about 2300rpm, and no NA-SBM is excited to pull from there, especially one with a cam that unlocks 340hp. By 40mph,the engine is still only at about 3100, and by 50, its finally approaching the fat part of the torque band at 3800.
>So, at speeds below 32mph, you will always be wanting to downshift.......unless it just blows the tires off then........in which case you'll want to fix that first. In this case, more power is not the answer, cuz more power just makes more wheelspin.The real problem is the actual amount of power being delivered to the road,at zero to 40 mph;. not the amount of power at 5000 or 5500.
With a stick-car, there is no slip in a fluid coupling nor TM in the TC.
This means at low speeds,until about 35/40 mph in first gear, if the tires ain't spinning, the engine needs big torque at those low rpms that the 3.23s are locking you into.
There are a couple of ways to achieve this. A stroker was mentioned already. Then there's decamming it. Or swapping to an automatic. Or the simplest and cheapest is TM.
Or some combination of these.
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I found the solution to that problem in my combo, allbeit I started with a 3.58 stroke.
I took a bunch of cam out, swapped to a 3.09 low gear, and went to 3.55s. Now I have torque practically right off idle. NOW, by 30mph,in second gear the engine is doing 2540 rpm , that's 250rpm higher than 3.23s and a small-cam 360 makes pretty good torque there already.
But the bigger deal was the 3.09 low gearset. Now on the downshift, into first, the Rs climb to 4100 instead of 3500, and that's a whole nuther engine.
I dropped three cam sizes. And gained a mountain of low rpm performance.
The 3.09 is worth 16%TM , and the 3.55s are worth 9.9%
Just these two alone are worth 26% more TM and it works ALL thru first gear, from idle to shift-rpm, and the 3.55s continue thru every gear..
>If you decide to go to alloys, they will fatten up your midrange too, if you keep the cylinder pressure up. And for a streeter, IMO are worth more to me than 1or even 2 cam sizes.
Also if you go to alloys AND get the pressure up, you'd want to do that first. And the reason is because the engine's torque is gonna jump right up, and maybe you'll find the existing TM tolerable.
IMO......To get the most value from alloys, you want to get the pressure up to 180 or more.Some here on FABO have mentioned that they are running over 200psi on pump gas. I myself have run up to 190psi, and up to 11.3 Scr,in three different iterations of the same engine, all on 87E10. This gas is (R+M)/2, or equivalent to less than your 95RON, so far as I have been able to determine.
>If you put alloys on a 9.5 or even a 10.0-Scr engine, you will likely be disappointed, until the Rs get up there.
I would do whatever it takes to get the pressure up there, or I wouldn't do it at all.......in a streeter.
When you had it dyno'd, did you have headers on it?
I think this is a very important question, because you said it seemed to be a very strong engine. This usually points to a well engineered combo, that often includes a bigger cam. The bigger cam often has a lot of overlap, and the overlap period works best with headers and a free-flowing exhaust. There's quite a bit of power to be had in that overlap, that more or less gets stifled with log-manifolds. So that should be your first change,IMO.
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It's BS any way you cut it and proved at the track many times where the REAL numbers get revealed!
