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Hello everyone! I saw some threads here which dealt with questions about the GM Ecotec LE5/LE9 engine in Slingshot, and as I've got many years of experience with the engine in its earlier LE5 form, with many superlative results, I wanted to offer a discussion here in the Hahn RaceCraft forum. I'm happy to share what I know about the engine, so consider this an open discussion. All are welcome to pose questions and/or offer their own insights.
We began to turbocharge the 2.4 liter LE5 in 2006, and immediately struck gold. We were delighted to learn that GM pulled no punches on this, their next chapter of Ecotec. Not only did the engine have a whopping 37 more HP than the 2.2 L61 which preceded it, it also featured a number of impressive internal enhancements.
Variable cam timing was added, giving the engineers a wonderful capability to further broaden the available powerband while ensuring great mileage and drive-ability. The pistons now featured anti-friction coated skirts, another first for Ecotec. Forged connecting rods used the latest in tapered small-end design that simultaneously strengthened the piston while reducing reciprocating weight.
As something which was relatively unprecedented for a normally-aspirated engine of that time, piston-cooling oil jets were added that actually sprayed oil into small cooling passages integral to the underside of the piston dome. Such cooling jets had previously typically only been on forced-induction engines (super or turbocharged), and as we do specialize in forced induction, we were naturally very enthused about this feature.
What the engineers did next continued to surprise us. Now, as we've been in the four-cylinder game since the 1970's, we've seen a number of such revisions from manufacturers over the years, especially such moves to larger displacement versions of existing engines. In every previous instance, such an increase was accompanied by a reduction in RPM redline, for a longer stroke and/or a larger piston exert more force at high RPM, and so the reduced redline was typical for durability. But GM did the exact opposite...when the LE5 was introduced it actually had a HIGHER redline than the earlier 2.2 L61! Now all the enhancements I mention above made even better sense...GM was hedging their bets by enhancing the engine internally to accommodate the higher RPM band.
Right away, we were mighty enthused, and as we'd been the first to turbocharge Ecotec several years earlier, we were chomping at the bit to boost this new player. Soon we had versions making a respectable 390 WHP, which represented over 450 HP at the crank...practically tripling the stock power level! What was most appealing about these high-powered versions was just how stock they still were. Save for valvespring upgrades, and of course our TurboSystem and fuel upgrades, these engines were still 100% stock internally. More on this as we proceed and discuss the subsequent versions of LE5, all the way up to the present time with Slingshot and its LE9!
We began to turbocharge the 2.4 liter LE5 in 2006, and immediately struck gold. We were delighted to learn that GM pulled no punches on this, their next chapter of Ecotec. Not only did the engine have a whopping 37 more HP than the 2.2 L61 which preceded it, it also featured a number of impressive internal enhancements.
Variable cam timing was added, giving the engineers a wonderful capability to further broaden the available powerband while ensuring great mileage and drive-ability. The pistons now featured anti-friction coated skirts, another first for Ecotec. Forged connecting rods used the latest in tapered small-end design that simultaneously strengthened the piston while reducing reciprocating weight.
As something which was relatively unprecedented for a normally-aspirated engine of that time, piston-cooling oil jets were added that actually sprayed oil into small cooling passages integral to the underside of the piston dome. Such cooling jets had previously typically only been on forced-induction engines (super or turbocharged), and as we do specialize in forced induction, we were naturally very enthused about this feature.
What the engineers did next continued to surprise us. Now, as we've been in the four-cylinder game since the 1970's, we've seen a number of such revisions from manufacturers over the years, especially such moves to larger displacement versions of existing engines. In every previous instance, such an increase was accompanied by a reduction in RPM redline, for a longer stroke and/or a larger piston exert more force at high RPM, and so the reduced redline was typical for durability. But GM did the exact opposite...when the LE5 was introduced it actually had a HIGHER redline than the earlier 2.2 L61! Now all the enhancements I mention above made even better sense...GM was hedging their bets by enhancing the engine internally to accommodate the higher RPM band.
Right away, we were mighty enthused, and as we'd been the first to turbocharge Ecotec several years earlier, we were chomping at the bit to boost this new player. Soon we had versions making a respectable 390 WHP, which represented over 450 HP at the crank...practically tripling the stock power level! What was most appealing about these high-powered versions was just how stock they still were. Save for valvespring upgrades, and of course our TurboSystem and fuel upgrades, these engines were still 100% stock internally. More on this as we proceed and discuss the subsequent versions of LE5, all the way up to the present time with Slingshot and its LE9!