I'm sort of in the "there's no replacement for displacement" camp, so I don't think I could bring myself to spend a bunch of money on an engine swap with less displacement than factory.
A big-turbo 2.0 L 4-cylinder might feel as peppy off-boost as the stock Iron Duke?
I don’t think this have ever been done, but I’ve seen my fair share of Fiero Lamborghini kit cars and most that have an engine swap, have the usual... 3800; My question... is there an actual Lamborghini engine that would fit in theFiero and to anyone’s knowledge, has it ever been done? I would love to see a sleeper Fiero, no kit, with a Lamborghini engine...
Putting this back into focus, his question wasn't specific to a V12. He just said Lamborghini. The V12s were posted as examples that there have been high cylinder count engines installed. The Gallardo and Huracan are V10s and the one Will posted was a V8. So,
Yup, the original question was about the look and sound of a rumbling Lambo engine in a Fiero. I read lots about 3800 and other cool engine swaps, but wondered about Lamborghini in a Fiero. I also love the sound of the 351 Cleveland in a Detomaso Pantera.... music to the ears. It’s not always about 1/4 mile drag times (I’ve never raced, but that would be cool too). I was at a gas station a month or so ago and a Ferrari owner pulled up beside me and he was truly enamoured by my little red 6 banger 2m6. We swapped stories and I had to look under the hood of his Ferrari... all engine and what a sound. In that moment I thought wouldn’t it be cool to lift the lid on my Fiero....
I'm sort of in the "there's no replacement for displacement" camp, so I don't think I could bring myself to spend a bunch of money on an engine swap with less displacement than factory.
A big-turbo 2.0 L 4-cylinder might feel as peppy off-boost as the stock Iron Duke?
You are kidding, no?
A stock LNF engine puts out max torque from about 1600 rpm - they have to artificially limit it so it doesn't tear up the driveline which is why it has that artificially flat torque 'curve'
And that is a stock LNF with 260Tq and 260 bhp - I run a conservative 375 bhp and 375 Tq in my street car (modified turbo) and many people with Cobalts and Solstices run well up toward the 500 bhp range. They will never sound as good as an engine with more cylinders, but they can't be faulted for power and reliability. Here is a video of a street driven Cobalt on the dyno - pulling 570 bhp.
You can't show a stock LNF dyno (which appears not too bad) and then claim that a big-turbo LNF will have the same low-end torque... I looked at the 570 hp Cobalt video, but the torque curve wasn't clear, as the camera zoomed in on the peak numbers. You got a dyno graph for yours?
From the stock LNF dyno graph, torque is poor at 1000 RPM. It's the same as a 2 L NA engine. For normal everyday driving with minimal clutch slip, more torque at idle is nice for leaving from a stop (harder to stall the engine). In street driving with most cars, I typically have full clutch engagement by 1000 RPM.
I drove a 2015 Golf VW 1.8 TSI... supposed to be one of those 4-cylinder turbo wonder-engines. Guess what, it lags too at low RPM. I tried driving up a hill in top gear at 1500 RPM; it took seconds for the turbo to kick in. Until the turbo kicked in, the Golf felt like a real ordinary NA econobox. From idle, the 1.8 TSI launches just like any other econobox.
Is GM that much better at this than VW? I haven't had the chance to try an LNF.
[This message has been edited by pmbrunelle (edited 11-15-2020).]
I haven't driven the VW so can't compare the two. The LNF pulls very strongly from very low down. The program limits torques in first gear lest you wind up sideways and with little rubber left, but is left unlimited in the other gears. Driveline loss is a bit less in the FWD cars using the engine (Cobalt SS) and starts are very fast from low down.
My 30 mpg street car does 0-60 in under 5 secs. which as you pointed out doesn't sound as much as it used to in the days of the Tesla, but is still pretty quick for a front engine rear drive car. My turbo Fiero would have been similar 0-60 due to better weight distribution but IIRC was just over 13 in the 1/4 while the street Solstice gets into the 12.9 range. And that is without burning up the tires.
I am not at all a drag racer - I spent decades road racing sports cars, but I do appreciate crisp acceleration even on te street.
While the basic physics of bigger turbo = more lag can not be sidestepped, the combination of variable cam phasing and direct injection reduces lag and improves the turbo's transient response.
But no, a small 4 with a big turbo will never accelerate uphill from 1000 RPM in top gear like a V8 would. While doing that is cool, I'm not sure it's any more necessary than the ability of a car to parallel park itself.
Yes and no. I've found that theory to have died the death of compression ratio guidelines for boost and fuel grade of 20 yrs ago. Modern engines and modern turbo designs are far more efficient. GM turbo cars are usually sporting 10+ to 1 compression with boost, which would have and has netted insults for anyone attempting such builds not very many years ago. The same with compression limits and fuel. To my knowledge, the highest stock compression ratio GM has rated for regular unleaded is 11.7:1 (No doubt they can make it an even 12:1 all else the same) in the 3.0L V6, which is basically a smaller displacement 3.6L currently at 11.5:1 on regular. Less than 20 yrs ago some might have argued you could not do that without premium fuel.
The key to lagless boost is proper balance. Sufficient compression for strong off boost response to help eliminate the spool up gap and efficient intake and exhaust arrangement. Direct injection and dual variable camshafts clean up the rest. Of course there are limitations, but since manufacturers are building daily drivers, they're getting better at building turbo cars that respond like naturally aspirated cars and keep in mind they are seldom delivered at peak performance capability, often teased out by aftermarket tunes.
All of that from just a stock tune change. I have the same PCM operating system and a remark made in that article supports what I suspected in my HPTuner logs, the PCM can adapt to premium fuel use (based on tune limits as these cars use a torque based program) in cars rated for regular, without a fuel grade sensor, by advancing the spark advance, and monitoring knock feedback, which I noted in my logs upon testing regular unleaded against premium.
A sluggish modern turbo car probably has far more to do with factory tune goals than performance limitations, as noted above in the LNF upgrade. There's about .2 sec difference in 0-60 times between the ATS-V turbo 3.6 and the supercharged CTS-V 6.2L with nearly a 200 hp difference and the better of the two 8 speed trannies. I doubt lag is part of the equation in this fairly balanced comparison.
[This message has been edited by Joseph Upson (edited 11-20-2020).]
The stock LNF output was actually 260 bhp/ 260 Tq. The factory GMPP kit changed a couple of sensors and the tune and yielded 290 bhp and 340 Tq, a significant boost. There were other after market tunes that gave around 310 bhp and torque similar to the GMPP tune.
If you also change turbos for a higher volume unit, you will increase turbo lag but you will also increase boost pressure. If you optimize some other stuff at the same time, you can head into the high 400s pretty easily.
I run 375 bhp/375 Tq and there are no disadvantages - the lag is almost imperceptible
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