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After riding in a turbocharged GSR I am convinced that it is an excellent platform to build on. However, I am worried that if I put that much money into an LS then it would be stolen because Honda's and the aftermarket parts on them are very desireable. Should I purchase an LS and turbocharge it and take my chances with thieves or is it not worth the hassle? I apologize if this post should be in another section but I wanted to get some opinions from those with turbocharged Honda's.
BTW:I have been on the boards for over a year. I have done a lot of reading and posted a few times but for some reason it says that I am a newbie. Oh well, I just wanted to clear that up so people don't start telling me to go read a bunch of the posts that I already have.
 

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Where did I get confused about the GSR and LS. I mentioned that I rode in a boosted GSR and would like to build upon the Integra platform. When I said that I thought it was an excellent platform I meant the Integra, not just specific to the GSR. The major difference between the GSR and the LS is VTEC. I don't care about VTEC if I am going to turbocharge and the LS block has a lower compression than the GSR so it will be a little better for boosting without building internals. If I remember correctly the LS tranny also has gears that are a little bit taller, but that is not a bad thing. I would be modifying the whole suspension so I could care less that the stock suspension on the GSR is better and I don't care about the leather and other amenities that the GSR includes.
 

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higher compression is better for boost. less boost and more power. Careful tunnig and dyno time are the keys to having a successfuly boosted high compression boosted car.
LS is a cheap way to go fast and I recomend it to anyone who is on a tight budget.
just my .2 cents

Blaze
 

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Blaze said:
higher compression is better for boost. less boost and more power. Careful tunnig and dyno time are the keys to having a successfuly boosted high compression boosted car.
LS is a cheap way to go fast and I recomend it to anyone who is on a tight budget.
just my .2 cents

Blaze
:D just what i was about to say

the car is only good as the tuning. have lower compression will let you run more boost to gain power as a higher compression with lower boost, but there are lots of advantage going with higher compression.

1. turbo has to spin less to create boost.
2. more power when off boost
3. more headroom for power if you can tune the car right
4. quicker turbo spool-up

u can't just say you don't know how to tune and just go with a lower compression engine. i hear people say.."i can run 8psi safer on a B18B1 than 8psi on a B18C1." well yea, but you don't gain as much hp in doing so. want too make the same power as an 8psi'd B18C1? then you gotta raise the boost to about 10psi. now you gain the similar amount of power, but what about low end? how long do you have to wait for boost to come compared to the B18C1?

now people will say.."i can't tune so i'm just going to go with a low compression engine." hate to break to ya'll..but if you can't tune, don't even think about touching a turbo engine, even if it's compression is low. a few years ago, i remember a guy blew his engine with only 6psi. this was on a lowered compression (8.8:1) B18B1. :rolleyes: find out that he didn't have the right a/f mixture.

you can't just go trial and error (unless of course you have $$$ to waste) learn to tune then turbocharge it. no one goes to a good college without some kind of schooling. i'm not directing this post to any specific person, but just in general.

good luck!
 

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I agree with you guys. These are very good points being made. Although, I would rather go with a lower compression motor so that there is a larger margin in case something does go wrong. I'd rather sacrifice horsepower so that I can have more reliability. This is exactly what the Taurus SHO guys are doing so that there engine doesn't blow up. Until a couple of months ago there were only a few ways to tune the EEC-IV on the Taurus SHO and tuning was quite difficult so a lot of Supercharged SHO's would run very rich above 6500RPM. Granted, this lowered the power output but the reliability was greatly increased. The detonation that once occurred very often is now a very low occurance.
 

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I would say if you have plenty of money, and lotsa of time to get it tuned, go with a turbo gsr motor. It's an awesome setup, which most of the civic drag cars are using. But if you're on a tighter budget, go with the LS motor because of the lowe compression which is more turbo friendly. That is why most all manufacturers that produce turbo cars have low compression engines. Such as the Mitsubishi Eclipse, Mazda MP-3 turbo, Mazda MX-6 GT, and the Volkswagen 1.8 T , etc.
 

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One main concern in power production with forced induction is effective compression. Effective compression is the sum of the motors static compression, plus the additional compression added by the forced induction tool. A B18C1 (also B16A) motor will have a higher effective compression than a B18B motor will, on the same boost...therefore, pound for pound, it will make more power.

The next argument that people usually bring up is that a higher compression is bad for turbocharging. Well, if you understand the concept of effective compression, then you should understand that this statement is entirely incorrect. A higher compression engine makes more power in NA form. So, why do you turbo guys think that a lower compression turbo motor makes more power? Does that make any sense when you really think about it? A turbocharger is a power adder? So why deplete power that was there to begin with? The answer I usually get to that is "So I can run more boost!" Well, sorry to rain on your parade, but more boost does not always equal more power. Check out this mathematical example of effective compression:

A motor with a 10.0:1 static CR boosting 10psi
10psi/14.7psi = .68
.68 + 1 = 1.68
1.68 x 10 = 16.8 effective CR

A motor with an 8.5:1 static CR boosting 10psi
10psi/14.7psi = .68
.68 + 1 = 1.68
1.68 x 8.5 = 14.28 effective CR

Now tell me who is going to make more power? The higher CR motor, or the lower CR motor?

So, maybe add more boost to the lower CR motor, right? Wrong...

A motor with an 8.5:1 static CR boosting 13psi
13psi/14.7psi = .88
.88 + 1 = 1.88
1.88 x 8.5 = 15.98 effective CR

Now you see, even adding 3psi of boost, still does not equal the effective CR of the higher compression, lower boost motor.

Effective compression is not the only advantage of the B16A/B18C1 either. The B16A/B18C1 has a stronger, better flowing cylinder head. It can rev much higher, making it that much more effective, and it flows great to handle all of the extra volume. The block has oil squirters to help support the bottom end assembly at high RPM. It takes more than a valvetrain upgrade to make a B18B safe at 8k. The higher compression also aids in spooling the turbo faster too.

Both motors have similar tolerances though. Both motors pretty much top out at around 350-400hp on stock motors, very well tuned. The B18C1 will make it far more efficiently for you though. It takes less boost to do so, it has more safeguards...and the bottom line on any Honda motor is tuning. If it is well tuned, you will be set. That goes for both motors. YOU ARE A FOOL if you think for one second that just because your B18B has a lower compression, you can substitute that for proper tuning.

A lot of people like to lower their motors compression when they build their motor. I used to think it was a good idea before I understood about tuning, and the positive aspects of compression. In the mathematical representation below, I will show you how a low compression motor must boost more to equal the output of a higher compression, lower boost motor:

Motor: stock B16A2 boosting 7psi.
Static Compression Ratio: 10.4:1

((boost psi / 14.7) + 1) x motor compression = effective compression

Stock motor (10.4:1 CR) on 7psi:
7psi/14.7psi = .47
.47 + 1 = 1.47
1.47 x 10.4 = 15.288 effective CR

Built motor (9.0:1 CR) on 7psi:
7psi/14.7psi = .47
.47 + 1 = 1.47
1.47 x 9 = 13.23 effective CR

You will lose 2.058 points from your effective compression ratio, this translates to a significant power loss.

In order to gain back that power, you have to do this:

Built motor (9.0:1 CR) on 10.5psi:
10.5psi/14.7psi = .71
.71 + 1 = 1.71
1.71 x 9 = 15.39 effective CR

Add 3.5psi to what you were boosting before, and you should be able to make around the same power as before, granted you haven't done any other kinds of modifications port/polish, cams, etc...

As you can see, considering all things stay equal (bore/stroke/cylinder head/etc...), you must add 3.5psi to make the motors perform similarly. You just spent about $2,500 to build your bottom end, and make your car slow.

By now we all should understand the positive aspects of compression, and how when teamed with the faster spoolng turbo, more efficient output, better flowing B-series VTEC cylinder heads, better low end spool time, stock oil squirters, higher redline, etc...you should see that turbocharging B-series VTEC motors is clearly not dangerous, and highly adviseable. I love a good turbo B16A!
 

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How about turbocharging a LS/VTEC? Is it the same as a turbo gsr?
 

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There is another thing you all are forgetting. The power band on an LS is awesome compared to a GSR or an Si when you boost it. The LS motor makes more torque than either of those other motors stock. When you boost it...it feels like a V8 powerband. My LS is an auto . I raced a Civic Si With a Drag 3 kit just like mine. I was at 8-9 psi and he flashed 10 between shifts. I handed his ass to him from a roll. We didn't race from a dead stop. We were rolling at like 20mph.
 

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I LOVE MY LS SWAP the motor has some much potential that it isnt funny.. me in na mode now with no cat the tanabe super racing medalion, home made intake, 9lb flywheel with centerforce clutch i can be rollin around 20 or so in 1st slamm it to the floor and the front tires just break loose like crazy and fly's up to the cheese 6800 rev limit ;(.. i just ordered some rc 440's for it and slowly piecing my kit together but my goal is 10psi on stock internals but dont think ill get there lol buy rods and pistons in a week heh.
 

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i'm on a 5k budget so thats mostly why i'm goin for an ls motor. the 5k should take car of a car, ls engine, gsr tranny and a custom turbo then i can find money sumwhere else to build the internals. yup, my budget makes most of my decisions. about how much would the internals cost. just a simple build not a street monster.
 

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eagle hbeam rods = 350
je pistons = around 350 all im doin i want liek 10-12 psi daily driver.
 

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im not sure but i think the stock sleeves can take atleast 15 psi before there bad but i may be wrong.. im more worried about the pistons and rods the things that tend to go under boost. but ill throw it together and see how it runs hehe i scored the rc 440cc's for 200 bux off ebay :D things have 500 miles on em should be good enough for 10psi
 

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x3mhonda said:
i'm on a 5k budget so thats mostly why i'm goin for an ls motor. the 5k should take car of a car, ls engine, gsr tranny and a custom turbo then i can find money sumwhere else to build the internals. yup, my budget makes most of my decisions. about how much would the internals cost. just a simple build not a street monster.

$1000 - LS Swap
$2,300 - Max-Rev Turbo Kit
$420 - Hondata S100
$300 - RC 440cc Injectors
$350 - JG intake Manifold
$300 - GReddy Profec B boost controller
$100 - GReddy Turbo Timer
$100 - ARP Head Studs (to keep the head from lifting)
$50 - Test pipe 2.5"

These are more or less street prices for brand-new parts.
You can find parts cheaper or used parts.

Good luck.

I would stay with the LS transmission on the LS motor if you're turbocharging. You won't have enough revs with that GSR transmission.
 

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x3mhonda said:
... the 5k should take car of a car, ...
u missed out that part in the list thats why i'm going with a custoom turbo to save on cash. and i was going with the gsr tranny cause they say that the ls gears are to long for street and the gsr woul handle the extra hp better. but i'm still looking into, i got time.
 
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