A&Q about 350Z
Q:
i'e read the FAQs, the "new threadstarters please read" etc., and haven't found the answer to this:
many Hondas i have driven seem to make HP only at very high RPMs, while VW and especially Nissan engines make power better at low rpms.
can anyone explain to me what the critical design differences are that make VW and Nissan engines more capable at lower RPMS, even though their displacement is similar to the Acura/Honda engines?
thanks!
A:
Well, if you drove hondas with vtec, that's why you felt alot more power at higher rpms. There's a thread all about vtec but I'll sum it up a bit. there are two cams, one aggressive one and one that's meant more for economy. At a certain rpm, a hydraulic actuator locks the two valves together and they take on the profile of the more aggressive cam. This gives vtec engines good smooth idling and driving capabilities and good fuel economy but they can still have power at higher rpms. Nissans and VW's don't have this so if they want performance, they will need to give up some fuel economy and have more power at driving engine speeds.
If you want to know more about vtec look at the top couple of threads in this forum and you'll see "important: honda's vtec"
A:
there is more to it than that. Nissan has a VVT system (its name sliped my mind). Vtec isnt ment to have econo cams and then super performance cams though it seems that way. the isea behind vtec is to have low high lift short duration for lower RPM's for better torque and smoother idle and low RPM operation and longer duration in higher RPM's for beter breathing and more HP.
other things affect the RPM band in which an engine makes best power or has the flattest torque curve. Bore and stroke are one. shorter strokes will make more power at higher RPM's and will be able to rev higher. Intake Manifold design has a BIG role in where an engine makes power. so do head design. also the spark and cam advancement and a/f ratio's as the enigne speed changes. on top of VW's whole marketing scheme is lots of torque from semi econo engines for best daily driving.
A:
thanks.
yeah, i was extremely underwhelmed by the performance of a 2002 RSX type s Acura i drove. it made noticable power only in a tiny sliver (6000-7500 rpms)
i am looking for something with a wider band.
A:
The reason that the Honda engines made less low end power is because the engines are probably a lot smaller than the VW or nissan engines. Like everyone said above, VTEC has a lot to do with the power band in a Honda, but if you want to change the engagement rpm, you can get a diagnostics tuner or Hondata system and lower the VTEC rpm or buy a VTEC killer cam that only gives high range VTEC no mid. Meaning that there is a blast of power when VTEC engages instead of the baby lobes that are on the stock cams.
Also there are tons of parts including turbos for Hondas so the possibilities of a Honda is a lot better than that of a VW.
A:
Wow this is news. I didn't know you couldn't put a turbo on anything but a honda. I thought there were other cars out there that had more potential than a civic but I guess I was wrong.
A:
i was under the impression that v-tec motors werent good under high boost.
A:
Very few enignes will handle high boost with out the proper preperation.
As for why different manufactors produce engines with differnt power curves?
Well they each have thier own pholosophies, and ideas on how an engine shuld be built and how it should perform.
And they all spend differnt amounts on R&D, and have differnt requiments for thier enignes.
Honda has a history based around motorsport, they have been involved and active in F1 longer than any other manufactor except Ferrari and most of thier engine designs are enfluenced by thier motorspoty activties. Thier chassis designs are also influenced in a similar way, and so thier cars have a reputation as being a bit sporty and generaly fun to drive. Its what happens you use the same enigneers to design your passanger cars, and your F1 cars.
Honda also started building sports cars and race cars long before they made the Civic
Nissan on the other hand is a little differnt.
Prior to about 1980 all thier engine designs had been copys of out dated British Leyland and Mercedes designs, either copyed, or made uner licence. When they started making thier own engines they based them on these old designs. They all used very strong bottom ends and very basic cylinder heads with limit flow capacities, but they ablity to make lots of useable power and torque at low rpms.
Nissan started to develop these designs, and the CA18 series of engines combined the strong bottom end with a well designed cylinder head. Then at the end of the 80s they started to get into financial trouble, and it began to show in their cars.
The SR and RB series of engines both used a very well designed bottom end that is one of the strongest ever made, but thier cylinder heads were, when compared to other designs, rather poor.
Quite simply they couldn't afford to develop a good head, and instead developed some very very good turbo systems.
A:
thanks. that is useful info....
i am now looking into a Tiburon.
A:
Since when is a honda fun to drive?
A:
You can post jackass remarks all you want, but you know what i meant. Of course there are turbos for everything, but there are way more parts for Hondas and that is what i was saying. Thanks for being the ass in the group!
A:
I thought that my cousin's friend's 800 hp Honda Civic was fun to drive.
Anyway, As Moppie said Honda made F1s for so long that I guess they wanted their cars to have a good HP level at higher Rpms just like their F1 because why mess with a formula that worked in F1 racing?
AS for VW, Think of where Vws are made. Germany. WHat does germany have? THe Autobaun. VW needed a really good midrange so it could get their cars up to a high speed faster, without having to smash on the gas to accelerate quick. Have you ever seen the new VW Jetta commerical were the saler and a guy is in the Jetta and he says to accelerate and he says, "Look how the acceleration kicks in at a lower RPM so you can quickly pass cars. This car was made for the Autobaun." They weren't kidding about that. Hence why VW engines have a better midrange.
A:
800hp civic? You'd be smoking wheels all through 1st and 2nd and halfway threw 3rd
A:
acutally all through 3rd. It doesn't help that I suck at stick because it was my like 2nd driving stick. BUt it was fun to get snapped back and pinned into your seat when you start out and it feels like a rollercoaster since I am so used to my 150 hp Sunfire. And the sound was so cool not like the big ass fat can mufflers just a suddle hum and the PSST! of the turbo.
A:
wait for it...
wait for it...
Hey! There it is!
He probably told you it was 800hp, and its more like 300-320hp. Nothin to sneeze at... but 800hp is more than a lot. He would have to be pushin well over 30psi and revvin to 10k+ to get that much out of a 4. And if he was, he sure as hell wouldn't let someone whos driving experience that consists of a 150hp sunfire drive it.