Hi all,
Just test drove a 2003 6 speed manual which was a great little car.
A quick question:
The VVT didn't seem very noticable while driving as in there was no spike in the power - is this normal as I have an Alfa 156 with VVC and the power spike is quite noticeable at around 3000RPM?
Thanks
4,500 revs and you WILL notice it!
I didn't realise the Alfa had a form of variable valve control? Big fan of the twin sparks !
From what I undersand the VVT on the MR2 is an intelligent system, it starts working at something like 3000 rpm until 4500 where it is operating at its maximum, this limits the sensation of one jolt. It's probably worth mentioning that the system is not the same as the VTEC system or Toyota's own VVTI with lift, where the cam swaps, wth this type of system the 'change' is more noticeable.
Also if your driving sedately the VVTI is barely noticeable, whilst if you floor the accelerator there is a definite change at 4500rpm.
If you do a search there will be people who can explain it a lot better than I can!
Given you were probably with a dealer at the time, the VVTI 'change' is hampered to a certain degree with the extra weight. Given the car is a PWR car, the difference between driving alone and having someone sit alongside you is massive. (To me at least!)
Glad you enjoyed your test drive though!
Quote from: "MRMike"From what I undersand the VVT on the MR2 is an intelligent system, it starts working at something like 3000 rpm until 4500 where it is operating at its maximum
Actually it's working from idle to rev limit. You can disable VVT-i through the diagnostic port and the car will die on idle. And in Power FC it's tuned by 20x20 map, just like ignition and injectors.
And there's no power peak, cause VVT-i makes the power curve smoother, not spikier. Without VVT-i, you could have the same max power, but lot less torque in lower rpm's.
Just a thought, 3 weeks after I tested an 04 6 speed I went and bought one s:D :D s:D
I didn't really notice the 4.3k surge on my test drive. Now, having done 4.5k miles, it is noticeable. The engine feels stronger and happier at those revs and it now feels slow when the engine is below 4k.
As had been said already, it's not the same as a VTEC kick.
I quite like the fact that there's no real 'kick' and not having to rev the nuts off the engine, it makes it much more usable round town with less gear changes. i think it has a very square torque band from 4k onwards...
Quote from: "Tomr2"i think it has a very square torque band from 4k onwards...
Actually the whole torque curve is dead straight to 6k...except that hump between 4-4.5k, which btw is caused by...uhm...no idea of the english word. But every engine has similar hump, the place varies depending on bore/stroke, but it is there. It has nothing to do with VVT-i...except the fact that VVT-i makes it more obvious, cause the torque curve is level.
m http://koti.mbnet.fi/temmeke/tmp/dyno.jpg (http://koti.mbnet.fi/temmeke/tmp/dyno.jpg) m
bloody hell, it really dies off after 6k! cant say ive really felt it, but thats probly beacause thats where maximum bhp is?
No, max BHP is lower down, around 4-5kish IIRC.
Quote from: "krisclarkuk"No, max BHP is lower down, around 4-5kish IIRC.
According to Tem's dyno plot, 6250rpm s;) ;) s;)
Though I forget what spec Tem's car was when that was produced (I'm sure I did read about it once.. but I have all the memory retention of a goldfish sometimes!)
Thanks for the info on the cam change.
the Alfa Twinspark engine really roars after 3000rpm especially with the remap, drop in K&N filter and the intake sound baffles removed
I couldn't really nail the car as the dealer was in the passenger seat so am looking to take an extended test drive for one evening on my own and then throw it around a bit - plenty of roundabouts in Swindon to try out.
What mods to the engine are the best bang for the buck - only concerned with power increase, not sound (even though the engine did seem quiet even with the hood down)?
Quote from: "Kristian"I couldn't really nail the car as the dealer was in the passenger seat
Pfft, that's never stopped me s;) ;) s;) (Have fond memories of turning a Nissan dealer white in a 100NX.. I know I know, terrible car.. I was young(er)!)
QuoteWhat mods to the engine are the best bang for the buck - only concerned with power increase, not sound (even though the engine did seem quiet even with the hood down)?
You'll get told to search in a second, I bet s;) ;) s;)
Biggest bang for buck has to be a remapped chip - don't bother with an off the shelf 'superchips' or similar, though. If I recall, Martin (mph) got 25-30bhp from a full mapping, cost around £450, before going turbo.
A search on his name & 'chip' ought to reveal the name of the chip, if nobody else chips in with it (groan), as my memory has failed me again..
To go with the chip though you'll really want a decent exhaust (H&S are very popular on here, there's a link in Grant's (GSB) sig).
Go for a K&N-style open filter only if you really want the sound - the engine bay is so hot in the corner where the filter is that you'll lose power. Best option at the moment is an intake pipe from H&S (via the club, if you can get one) which removes the giant restriction in the standard item. You get most of the sound benefit of an open filter, but all of the benefit of more cold air. Possibly add an 'uprated' panel filter, but the jury is out on that one..
Aaron
All good points, for the Unichip data, go to the last page of the Performance forum, the post with all th info is called "Unichip Experience?" or something along those lines...
As for the Hayward & Scott. Click below... s:wink: :wink: s:wink:
Quote from: "GSB"for the Unichip data
That's the badger.. although the name that I was trying desperately to remember was Dastek..
Don't think you needed to post that twice though Grant.. quick, delete the second one before anyone notices s;) ;) s;)
Right.. back onto topic..
Quote from: "GSB"All good points, for the Unichip data, go to the last page of the Performance forum, the post with all th info is called "Unichip Experience?" or something along those lines...
As for the Hayward & Scott. Click below... s:wink: :wink: s:wink:
I though we were all going to go for one of these Grant; still interested s:?: :?: s:?:
Quote from: "krisclarkuk"No, max BHP is lower down, around 4-5kish IIRC.
maximum bhp is 6400rpm chris
quote from toyota website:
"What's more, they each develop 138 bhp at 6,400 rpm. But then figures alone can never adequately describe just how exhilarating they are to drive."
Quote from: "Tomr2"Quote from: "krisclarkuk"No, max BHP is lower down, around 4-5kish IIRC.
maximum bhp is 6400rpm chris
Think it's the torque that peaks about 4.2k IIRC.....err, maybe s:? :? s:?
Ally.
yeah that could be what i was thinking... s:roll: :roll: s:roll:
Oh, and its KRIS not CHRIS s:evil: :evil: s:evil:
yeah sorry mate! realised after i posted Chri.. er... i mean Kris s:wink: :wink: s:wink: s:lol: :lol: s:lol:
i went for my test drive last week...... ended up going back 2 days later to order one.
Bad thing is ive decided to wait foor new reg so its a 4 week wait
Quote from: "MR2Roadster"Bad thing is ive decided to wait foor new reg so its a 4 week wait
It will be worth the wait s:wink: :wink: s:wink:
Quote from: "MR2Roadster"i went for my test drive last week...... ended up going back 2 days later to order one.
Bad thing is ive decided to wait foor new reg so its a 4 week wait
It took you two days to decide? s:lol: :lol: s:lol: I think myself like most left a deposit on the test drive! Great to see your getting one, even if you do have to wait a bit! Leaves you to decide what your going to add first though! s:wink: :wink: s:wink:
Whoop, whoop! Another one into the fold! s:lol: :lol: s:lol: Start exercising your jaw now... s:wink: :wink: s:wink: