RE: Jeep Grand Cherokee SRT8 revised
Discussion
I have driven the 5.7 Hemi around NYC a few times. It is funny being able to use the power to nip in and out of traffic almost like a smaller car. The one we had in our family had an irritating delay to the accelorator when my mother in law first got it. This is a known issue witht he fly by wire system they used. After a couple of years ownership she took it to the dealer for a routine service as she had done many times before. When it came back the throttle response was immeadiate. It was obvious to me that it had been effectively re-mapped with some firmware upgrade but the dealer did not admit to it. Much better for it though!
The only issue was that it did not like going slowly. I was driving it in a funeral procession at just above walking pace. It didn't want to be at that speed so I had to tap the accelorator and then take my foot off completly instead of keeping it at a set level. With every tap there was a roar of the V8 which made me look very antisocial being dirrectly behind the hearse.
The only issue was that it did not like going slowly. I was driving it in a funeral procession at just above walking pace. It didn't want to be at that speed so I had to tap the accelorator and then take my foot off completly instead of keeping it at a set level. With every tap there was a roar of the V8 which made me look very antisocial being dirrectly behind the hearse.
Jimbeaux said:
If you find yourself behind my hearse, please let your V8 roar! 
Sold it now for peanuts (around $10k). If you plan on passing away soon the only V8s we have in the family are the 2010 5.3L Twin cab Chevy Silverado or the 2001 S430. The Silverado could double as the hearse on good weather days if it wasn't white.h0b0 said:
Jimbeaux said:
If you find yourself behind my hearse, please let your V8 roar!
Sold it now for peanuts (around $10k). If you plan on passing away soon the only V8s we have in the family are the 2010 5.3L Twin cab Chevy Silverado or the 2001 S430. The Silverado could double as the hearse on good weather days if it wasn't white.
RedBull said:
I never really "got" 4x4s for pure road use until I bought my Grand Cherokee, now I get it completely. So one with a bonkers great Hemi and frankly ludicrous performance for an "off-roader" would be a fantastic laugh.
My Grand Cherokee is big enough to dump a server cabinet in the back, has enough torque to tow two horses (could probably bloody tow the field), is comfy enough for a 6 hour drive, overdrive is absolutely perfect for motorway sailing (2000rpm @ 75mph), sensible enough to pick the grandmother up in, is fast enough to nip in and out of traffic/put the boy racers to shame from the lights and best of all sounds epic at 5500RPM.I've honestly never had as good an all rounder!
I recently bought a Grand Cherokee SRT8. So many people on this forum just roll out the standard "it's a fat SUV that has no purpose in the world" without ever having driven one. I am mad about cars, I've been a petrolhead since I was a kid. My wife is long-suffering due to my obsession. The Jeep is every bit as "evo" as the other cars in my life which include a C63 and 370Z. I don't have the C63 anymore; I wanted another car to give me that V8 sound and acceleration while being more family friendly with a better ride. The GC fits the bill perfectly. I have done a few thousand kms in the Jeep now and much prefer it as an overall car compared to the AMG.
All this talk of poor cornering is just total b******s. I got back from a trip to the Victorian Alps last week and the Jeep provided all the interaction and handling ability that I would want from a car on the road. In 'sport' mode, I very much doubt most supercars would be able to get away from it. Yes you can't tail slide it but most Audi RS cars are the same so what?
If you drive on the track regularly and can only have one car then yes this wont float your boat but that was never the point of it. As an all rounder for the road however it is awesome.
All this talk of poor cornering is just total b******s. I got back from a trip to the Victorian Alps last week and the Jeep provided all the interaction and handling ability that I would want from a car on the road. In 'sport' mode, I very much doubt most supercars would be able to get away from it. Yes you can't tail slide it but most Audi RS cars are the same so what?
If you drive on the track regularly and can only have one car then yes this wont float your boat but that was never the point of it. As an all rounder for the road however it is awesome.
Joecooool said:
I just bought the 5.7 Hemi version. It has 360 hp and is pretty peppy.
It continues to baffle me how America manages to squeeze so few horses out of so many cubic inches.Is it all down to the watered-down petrol, or is there some other reason the engine is so strangulated?
AdeV said:
It continues to baffle me how America manages to squeeze so few horses out of so many cubic inches.
Is it all down to the watered-down petrol, or is there some other reason the engine is so strangulated?
Because a European V8 of similar capacity is a 32v DOHC affair that's bolted into a $100,000 car and its a $25,000 engine if it needs to be replaced while the 5.7 can likely be bought brand new for $4,000 and is bolted into a $39,000 car.Is it all down to the watered-down petrol, or is there some other reason the engine is so strangulated?
Heck, you can buy a BRAND NEW, not rebuilt Chevy small block from your local GM dealer (block, heads..no intake but fully assembled and ready to run) that makes 250hp. For....
Just over £1,000
It'll take 200k miles of abuse as well.
Oh, and Our fuel isn't watered down, that's an urban myth. We calculate octane ratings by averaging RON and MON, Europeans use the RON number only. Our "Premium" fuel is generally 93 octane. In Europe that's usually 98-100 octane fuel.
Oh,
And I drive SRT8 Grand Cherokees on a regular basis at work. We have about 8 of them floating around at the moment and they are, as people who have actually driven them have said, an absolute blast. Are they a bit crude? I suppose to a degree but nothing else comes close for the money and they are dead reliable.
And I drive SRT8 Grand Cherokees on a regular basis at work. We have about 8 of them floating around at the moment and they are, as people who have actually driven them have said, an absolute blast. Are they a bit crude? I suppose to a degree but nothing else comes close for the money and they are dead reliable.
I would absolutely LOVE one of these.
What I don't love is the price...it's not the initial outlay either really, it's the fact that the car will be worth buttons in 1, 2 or 3 years time let alone 4 or 5!
I regularly search them out on AT but so far haven't ever been able to find one.
Anyone know if any at all have been sold in the UK? (the pre-facelift obv.).
What I don't love is the price...it's not the initial outlay either really, it's the fact that the car will be worth buttons in 1, 2 or 3 years time let alone 4 or 5!
I regularly search them out on AT but so far haven't ever been able to find one.
Anyone know if any at all have been sold in the UK? (the pre-facelift obv.).
Haggleburyfinius said:
I would absolutely LOVE one of these.
What I don't love is the price...it's not the initial outlay either really, it's the fact that the car will be worth buttons in 1, 2 or 3 years time let alone 4 or 5!
I regularly search them out on AT but so far haven't ever been able to find one.
Anyone know if any at all have been sold in the UK? (the pre-facelift obv.).
They depreciate but they'll not be worth buttons at 3 years old! The cheapest one on AT is a 2006 for £15K & a 2008 for £18K.What I don't love is the price...it's not the initial outlay either really, it's the fact that the car will be worth buttons in 1, 2 or 3 years time let alone 4 or 5!
I regularly search them out on AT but so far haven't ever been able to find one.
Anyone know if any at all have been sold in the UK? (the pre-facelift obv.).
We had this discussion a while ago & someone looking for one couldn't find one in the spec he wanted as there are so few for sale at any time.
tr7v8 said:
They depreciate but they'll not be worth buttons at 3 years old! The cheapest one on AT is a 2006 for £15K & a 2008 for £18K.
We had this discussion a while ago & someone looking for one couldn't find one in the spec he wanted as there are so few for sale at any time.
There isn't a single new model that I can find on AT.We had this discussion a while ago & someone looking for one couldn't find one in the spec he wanted as there are so few for sale at any time.
The old one is available at 4 years old for £18K. Call it 15k trade.
£45k loss in four years on a £60k car is pretty horrific! 75% in 4 years!
I love these cars but not a grand a month in depreciation love them.
Haggleburyfinius said:
tr7v8 said:
They depreciate but they'll not be worth buttons at 3 years old! The cheapest one on AT is a 2006 for £15K & a 2008 for £18K.
We had this discussion a while ago & someone looking for one couldn't find one in the spec he wanted as there are so few for sale at any time.
There isn't a single new model that I can find on AT.We had this discussion a while ago & someone looking for one couldn't find one in the spec he wanted as there are so few for sale at any time.
The old one is available at 4 years old for £18K. Call it 15k trade.
£45k loss in four years on a £60k car is pretty horrific! 75% in 4 years!
I love these cars but not a grand a month in depreciation love them.
tr7v8 said:
I think they are special order these days. As for the depreciation look at say a Cayenne or similar. Won't be a lot different & considerably more expensive to buy in the first place.
I've just checked out the figures and you're right in the sense that in absolute terms a Cayenne S would cost about the same to lease as a Hemi (which means they must depreciate about the same). It's just the percentage figure that makes me want to cry!A grand a month is a lot though for a Jeep.
I still want one though
Just wish someone else would but a new one first and let me snap it up in a few years!
AdeV said:
It continues to baffle me how America manages to squeeze so few horses out of so many cubic inches.
Is it all down to the watered-down petrol, or is there some other reason the engine is so strangulated?
Oh and to help you out somewhat here's a few points to consider.Is it all down to the watered-down petrol, or is there some other reason the engine is so strangulated?
To get more power from an engine you basically need more air, more air + fuel = a bigger bang. In very simple terms.
To get more air into an engine you can:
-force it, buy means of a turbo or supercharger. This changes an engines dynamic or "effective" displacement, e.g. if you force twice the amount of air into a 2.0 litre engine it has an effective displacement of 4.0 litres. Down sides to forced induction are evidently cost (more parts, more R&D), more complex to build, design and maintain. More stress on the engine, often specific fuel requirements, often poor off boost performance and poor on boost fuel economy, power delivery, throttle response
-make it rev higher. The higher the revs the more air an engine will flow through it and the more power it can make. Downsides are to make use of high revs you need a more aggressive cam profile, however this means poor low rpm performance, so you need to use multivalve technology to gain better control over a wider rev range. This adds weight, size and cost. High revving engines are also more stressed and of course you need to rev them to get the power, so you have to drive them hard and need short gearing to make use of the power. Which can have negative effects on mpg and emissions
-make it larger capacity, which is kinda self explanatory. And has no real negatives apart from some stupid countries have cc limits for no other reason than political ones based on not understanding how an engine works.
So in the case of the Hemi V8, it's a simple OHV push rod engine with 2 valves per cylinder. This doesn't mean it can't rev high, but to make it breath at high rpms with only 2 valves means big valves and heavy springs. This would mean a lumpy idle and poor low rpm driveability.
Now the Americans are fully capable of building advanced multivale engines and have done so on many occasions. But lets look at this from a logical point of view.
The Hemi is compact and lighweight, in fact it's no bigger or heavier than many Euro/Jap DOHC V6 engines that only make half the HP. So on pure physical size it offers good performance to weight and good performance to physical volume/exterior dimensions.
Now Chrysler could if they wanted to take a Hemi engine and add some DOHC heads to it, it really wouldn't be that difficult. This would allow them to rev the engine higher while retaining a smoother low rpm performance. But adding DOHC would make the engine taller, wider and heavier, It would also add cost of manufacture and maintenance (4 cams instead of 1 for example). Also to dive 4 cams you'd have to make the engine longer to add a complex chain drive or cam belt.
So what would be the benefit?
Well ok you would now be able to extract more PEAK hp at higher revs without sacrificing low rpm performance. But do they really need more than 360hp? It's also a lot of work with a lot of downsides.
Ok you could say they could maybe make it a 3.8 litre engine instead of a 5.7 and still make 360hp by using a more complex DOHC setup. But physically such an engine would be no smaller on the outside, infact it'd still be bigger and heavier due to being DOHC.
So you then get to were and how the power is made. The 5.7 Hemi not only makes 360hp, which lets face it, no matter how you slice it that is a fair chunk of HP. But it also makes 385ft lb of torque. But the really critical thing here is where it makes it's torque.
Have a look at this dyno plot:
Of note:
-how much torque it makes low down. From the plot it looks like it doesn't start reading correctly until 2100rpm. At 2200rpm the Hemi is making 300lb ft!!!
If we use this formula:
HP = torque x rpm/5252
That means at 2200rpm the Hemi is making 126hp.
Now remember this 5.7 Hemi is not a performance engine, it's just a regular mass production unit. So it's cheap to build on mass and doesn't use specialist parts or short service intervals.
Low end grunt is for great for a 4x4 or truck yet the engine will still perform well in a car too, this makes it versatile and cost affect for a large motor organisation. Lots of low end torque is also good if you live in the mountains (remember some parts of the US are at the same altitude that planes fly at!!) and a low rpm cruising ability, which is good for long distances and mpg.
Now we can compare the Hemi to a high specific output engine. The 3.7 V6 in the 370z Nismo makes 350hp, so is comparable from a PEAK hp stand point. But the thing to note here is, the Nissan only makes 276ft lb of torque. 110ft lb down on the Hemi.
But more importantly if you look at a dyno plot for the Nissan:
At the same rpm (2200rpm) it's only making 220ft lb of torque.
Using the same equation that means the Nissan is only making 92hp at these rpms vs 126hp for the Hemi.
So is the Hemi really only squeezing so few hp out for the cubic inch?
And remember the Hemi is still no bigger (probably smaller) than the Nissan engine in physical dimensions and likely as good on fuel too.
To close, it's not that American's can't make high specific output engines. But the bigger picture is, how much HP do you really need and if you can attain it cheaper, more reliably and with more low rpm performance in a smaller overall package - why wouldn't you?
Gassing Station | General Gassing | Top of Page | What's New | My Stuff