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[Discussion] i4 vs V6 turbo

Posted: July 19th, 2010, 11:10 pm
by chillined
Alright guys. I'm new here, what's up. I wanted to have a discussion with boosted i4 and V6 owners and see what their input on each type of engine. These are the points I can really come up with:

V6
- Less Lag, More exhaust pulses, therefore having a smoother powerband than a i4
- More power..? (I don't know if this is true)
- Sexy sound :D

- More complicated than the i4 to build piping
- Tuning issues? (This is a big one I personally wanted to talk about..)
- More expensive...?

i4
- Less complicated
- Don't have to make custom pipes EDIT: Nvm, you actually do.

- More lag (Rougher powerband than the V6)
- Less Power? (Again, I don't know if this is true)

Re: [Discussion] i4 vs V6 turbo

Posted: July 19th, 2010, 11:39 pm
by Ryan
You can also mention that I4's in this car is limited to 1.8L
v6's get to 2.5L

Stock strength of the motors is also important.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 12:15 am
by RS_OBD'oh_2
B6 also works.

You can get the V6 pipes off ebay
4Cyl pipes are custom

V6 has the sub frame/cross member or whatever that needs to be moded

Power band/lag and the smoothness of the curve are all related to turbo selection and tuning. A poor choice in turbo or a crap tune will make any turbo project fail.

Neither will be all that cheap. Both versions have crazy potential.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 12:58 am
by Mi|<E
As above, lag is solely turbo size. You will have a smaller
turbo on a V6 than the I4. Custom piping on the I4 is
unavoidable but you can keep it clean and stock looking.

As per the power curve neither is easier than the other to
tune but cost is proportional to how well it is done.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 2:22 am
by chillined
I agree with both having crazy potential, but for some reason, I find that turboing a KLDE would be badass. I love V6's.
What is the difference in cost for the i4 and V6?

Edit: And I thought that the V6 would have less lag, in the sense where if the i4 and the V6 were running the same turbos. I'd believe that 6 pulses should spin up the turbine faster than 4 pulses.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 4:08 am
by Mi|<E
I4 has the entire exhaust bank into a single turbo, so
in my case for example 1.8L from 4 cylinders. In the KL
engines you have 1.25L of exhaust displacement turning
a turbo, half are on the other side. So smaller turbo for
the KL or you get mad lag.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 5:15 am
by onlytrueromeo
Mi|<E wrote:I4 has the entire exhaust bank into a single turbo, so
in my case for example 1.8L from 4 cylinders. In the KL
engines you have 1.25L of exhaust displacement turning
a turbo, half are on the other side. So smaller turbo for
the KL or you get mad lag.
Since when does anyone with a KL run a single bank turbo/? :|

In the long run, 4bangers are always cheaper and easier to maintain than V6's. Less parts to break, more engine bay room. What was not mentioned was for a bit more custom fab work, you can drop in the 2.0L FS engine.

I have a V6 and decided to keep away from the I4's (previously had a b6 mx3) because I wanted the all around sound, and greater N/A potential. I do plan to turbo, but it's expensive, and wanted a ZE to keep up in the meantime.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 6:39 am
by Mi|<E
My post wasn't worded correctly, the lag difference was
the point not the exhaust banks. More piping for the V6
whereas you have one solid equal length manifold for a
I4. The KL kits look nice but $$$

Learning to read surge graphs and doing some of the
calculations on garretts website will help with selecting
a properly sized turbo

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 10:04 am
by wytbishop
From a purely mathmatical perspective the 2.5L V6 has the greatest potential. I would also say that with the wider availability of turbo products it would be a much easier experience turboing a V6.

There is no connection between the "smoothness" of the power delivery and the number of cylinders. At 3000rpm each cylinder fires 50 times each second. So even in a 4 cylinder engine there are 200 spark events per second or a spark every 0.005sec. To the human perception that is effectively continuous. Compare that to a spark every 0.003sec and the change is absolutley imperseptible.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 10:53 am
by RS_OBD'oh_2
I would think the V6 would be cheaper. It all comes down to what your goals are. How much $ you have and how much power you want is a big factor.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 3:43 pm
by onlytrueromeo
I guess i fail to see how a V6 would be cheaper. the B6 and bp are both miata engines and stock logs and turbos can be had for relativelt cheap without relying on ebay brand parts. in terms of ultimate power, on paper a kl wins but in reality the 2.0L FSDE has proven to be extremly reliable and produced a 10sec mx3 albiet with lots of work but on a stock block. I4s are lighter an easier to work on. i still think V6 is the way to go since more power will be had ;or cheaper but as far as cost to turbo I4 is cheapest.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 4:37 pm
by wytbishop
I"m curious because I'm a little out of touch with the 4 cylinder stuff, but what's the engine management solution of choice these days for turbo BP's and B6's? Back 5 years ago when I was into 4's it was all SAFC pretty well.

My sense is that when it comes to engine management the MSnS route for V6 is a lot more straight forward (and probably cheaper) than other options for I4...but I don't really know anymore.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 8:57 pm
by RS_OBD'oh_2
onlytrueromeo wrote:I guess i fail to see how a V6 would be cheaper. the B6 and bp are both miata engines and stock logs and turbos can be had for relativelt cheap without relying on ebay brand parts. in terms of ultimate power, on paper a kl wins but in reality the 2.0L FSDE has proven to be extremly reliable and produced a 10sec mx3 albiet with lots of work but on a stock block. I4s are lighter an easier to work on. i still think V6 is the way to go since more power will be had ;or cheaper but as far as cost to turbo I4 is cheapest.
This all comes down to what kind of power you want. 150-180hp, the b6/bp can be done fairly cheap. Yes you can get the b6t bolt ons.. some of us want better. If you want good numbers and something that will last expect to buy good parts. This is the point where I will direct to you the worklogs. The mani and turbo are only the starting point. A KLDE swap + ebay probe turbo header is by far cheaper. Again, it all comes down to what you want out of your car. If you want the hp numbers, expect to open all these engines to upgrade the internals. Swap trannys, add LSDs.. the list goes on.

Mi|<e - BP god
Mine for the B6 - price list on page one
John or hppwdn for v6 stuff

When it comes to engine management, the sky is the limit. SAFC is quite crappy by today's standard. I am using an AEM F/IC and Mike went full stand-alone. $$$$$$$ is a big factor here as well. Pretty much any system out there can be made to work with any car. A lot of the install of the EMS/piggy is all on the owner. You can spend all the money in the world, but all for not if your local dyno/tuner cannot work with your system.

No matter what you go with, I hope you can weld or know someone who will work for beer.

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 11:02 pm
by chillined
What are the tuning options for the V6, both in standalone and piggyback? And what kind of boost would be the threshold limit of a piggyback system?

Re: [Discussion] i4 vs V6 turbo

Posted: July 20th, 2010, 11:17 pm
by RS_OBD'oh_2
chillined wrote:What are the tuning options for the V6, both in standalone and piggyback? And what kind of boost would be the threshold limit of a piggyback system?
Ok, I'm done.

How did you miss " any ems/piggy can work with any car" Even if you miss that, how in the f$#< did you miss the line: "You can spend all the money in the world, but all for not if your local dyno/tuner cannot work with your system."

So I get the idea that either you have no F'n clue or you don't bother to read.. either way, I'm out.. best of luck. Try F'n google or the search function.


F'n Lazy!