FAQ about Vitara pistons

[fjt]

Hello Guys.
I am hoping to create this thread to be very informative about the use of vitara pistons to boost Honda SOHC Engines. I will try to explain as much as i can based on the questions that i receive daily from other members. Please feel free to ask any doubt about the pistons that you might have and that is not posted here.

I will try to update this FAQ and keep adding info to it.

1. What are these Vitara pistons everyone talks about?

These pistons are found on the 1992-1998 Suzuki Vitara, 1.6liter engine. Piston code G16b
They are also found on the Suzuki Esteem

2. Piston Specs and Compression ratios?

The pistons come Standard in 75mm

Oversized sized---> .02" or .50mm or 75.5mm
.04" or 1mm or 76mm
Since you use the exact Same piston on different Honda Sohc engines, the Compression ratio will vary from engine to engine. The CR will be basically determined by the head you use because of its combustion chamber design and flow.

Vitara piston Compression Height--> 28.3
Vitara piston Dish volume (CC) ---> -15

To calculate compression ratios please use this calculator. Just put your engine combination.
http://www.zealautowerks.com/dseries.html

One important thing to know about the vitara pistons is that they have a Lower compression height compared to OEM Honda pistons.
What does this cause?
Well.. when you install the Vitara piston on aftermarket rods with the standard D16 length(137mm), the piston stays down the cylinder at TDC, in other words, the piston does not reach up to the top of the sleeve(on the JDM D15b is the opposite, the piston will tick up above the deck height). That is why you will see that on the CR calculator the Compression ratio that they yield is very low on D16(In the 7's) and IT IS NOT 8.5:1 CR as many people advertise(specially on Ebay).

Now, the setup will work with such low Compression on standard length rods and this is how everyone has been running these setup for the past 3-4 years with success. A good example of this is Speed's Factory EG that uses YCP Vitaras ans standard length rods(Eagles) and has way over 400whp and runs mid to low 10's at the track.

However we have developed a custom length Forged rod(Longer on D16 engines, shorter on JDM D15b) to specifically run with the vitara piston and provide a full point up in Compression(on D16) but we will talk about that later.

3. Will all vitara pistons work the same or handle the same amount of power?Which ones should i use?

In terms of piston size they are all the same but not all vitara piston manufacturers will make the same quality/strength piston.

The pistons that you want to get are the YCP Vitara pistons. Why? Simply because they are made of a much stronger cast than any other piston, even the OEM Suzuki. The piston goes through a process of Semi-Forging.

The YCP Vitara pistons are T-6 heat treated and made of AC8a grade(much ,ore stronger cast) aluminum.
They are aso Coated with teflon to add other qualities fin functionality for your engine.
They have dual oil Wrist pin Lubrication Holes
Because of the coating, they will provide smoother running, Better sealing for less blow by, better protection against heat and friction and detonation.

Another reason to go with YCP vitaras is because simply they have been proved to handle the abuse.

*Note: Nippon vitara pistons or any other brand that is so far out in the market wont handle the same amount of power that the YCP Vitara do. These pistons will fail at lower power levels because they are not made of the same material or go through the same manufacturing process and only the YCP Vitaras have been proven to almost 500whp

4. Will YCP Vitara pistons fit on aftermarket forged rods?

Yes. YCP Vitara pistons have a Floating wrist pin design, just like aftermarket forged pistons, and they will fit perfectly on D16 aftermarket forged rods (insert your preferred brand of rods here).

5. Will YCP Vitara pistons fit on Stock Honda rods?

With modification, YES.
The stock Honda rod is designed for a pressed fit wrist pin setup but if you take your stock ods to a Machine Shop theywill be able to modify it to accomodate floating wrist pin. They just have to bore out a little bit the small end of the rod so that the Vitara piston wrist pin can slide in the rod by hand and not with a Press machine.

6. How much boost and power YCP Vitara pistons can take?

This is a tricky question with a tricky answer, atleast on the boost figures. A small turbo at 20 PSI will push less volume of air than a large turbo at 20PSI. So 2 turbos at the same PSI level wont produce the same Horsepower results. In that case lets just talk about how much power they can handle and i will give you a PSI number later but related to a specific turbo size so you guys can have a better idea.

As in all setups, tunning is a very important key and that will shorten or extend the life of your internals. If you have a bad tune the pistons will blow, no matter if they are expensive forged units or cheaper Vitaras.

So taking into consideration that you can have a good tune, the most WHP so far that these pistons have been able to produce reliable has been 470-480whp.

In terms of Boost they have been able to hold 30PSI on T3/t4e 57 trim turbos

The fastest time so far recorded for a D16 Setup with YCP Vitara pistons is 10.48 @ 138mph.

7. My engine sounds like it spun a bearing after installing Vitara pistons.

This sound is normal and it is due to the floating wrist pin design. The pistons are noisy at startup and you car will sound like a Diesel engine. After the car warms up the sound decreases.

8. What piston to wall clearances should i run with vitara pistons?

Usually it depends on your Power goals. The pistons expand when they get to operating temperature.
The more power you are aiming for the bigger the piston to wall clearance should be.

If you use standard bore vitaras your pistons might be a bit on the loose side but it is not a bad thing if youre aiming for ove 400whp.

If youre using 75.5mm Vitaras and your power goals are between 250-350whp a good P2W clearance is between .003 and .0035.
For 350-400whp---> .0035 to .004
For 400whp or more---> .004 to .0045

As i mentioned you can run bigger clearances wit success. There are actually guys running as much as .008 P2W clearance on 400+ whp setups..

In my particular car, since i used 75mm bore and they tend to get loose my P2W clearance was .006 and i never had any problems of blow by or anything else.

9. What Rings should i use With Vitara pistons?
You can either use Suzuki or Honda Rings.. Actually the Suzuki rings will fit perfect on Honda pistons.

I usually use when i sell them---> Honda Hastings rings, NPR Honda rings, NPR Suzuki rings

10. To what direction should the arrow on the pistons point to?

When you install the piston on the block the arrow should point towards the timing belt.

[Autoworks]

great info :respect-047:

[91B20ED]

good work mang! stickied!

[gecko49]

how do i no if i got the bad vitars or the YCP vitaras

[91B20ED]

Originally Posted by gecko

how do i no if i got the bad vitars or the YCP vitaras

the box will say nippon on it. lol

[gecko49]

Originally Posted by 91B20ED

the box will say nippon on it. lol

fuck yup i feel like a noob i went to hiz website and the piston iz diffrent and mines say nippon racing ltd any 1 wanna buy them lmao jk im gonna see if i can sell them to the same guy i sold my 2 inch hal size radiater that i got from ebay for 110$ i sold it for 250$ :devil-0004:

[91B20ED]

Originally Posted by gecko

fuck yup i feel like a noob i went to hiz website and the piston iz diffrent and mines say nippon racing ltd any 1 wanna buy them lmao jk im gonna see if i can sell them to the same guy i sold my 2 inch hal size radiater that i got from ebay for 110$ i sold it for 250$ :devil-0004:

yeah man ive read the nippon vitaras are not as good.

[gecko49]

Originally Posted by 91B20ED

yeah man ive read the nippon vitaras are not as good.

if i dont sale them il keep them ans see how much boost they can handle but im gonna get the bottom end kit that FJ sales for cheap ANCING-banana-032:

[deddth]

excellent info. proof that fjt knows his stuff real good.

[burnoutboy]

Good to know my homework paid off. I was wondering about the P2W clearance though so that was much appreciated! EXCELLENT write up. So glad I went with FJT!! Supporting sponsors AND getting THE BEST parts available FTMFW. Cant wait to get my 75.5mm YCP Vitara's and 138.65mm I-beams!!!!!!!!!!!!!!!!1111!!!!!!!!11!!!!!1

[fjt]

Originally Posted by gecko

how do i no if i got the bad vitars or the YCP vitaras

1. the Circlips are different.
2. the piston does not looks as pretty...lol
3. Usually Nippons have a hole right in the center of the piston

4. The piston should have a number engraved on the inside wall that says 22108. ALso the YCP logo is engraved on the inside wall of the piston

5. YCP Pistons comes on a Blue/white box..Nippons comes on a Yellow Box

[gecko49]

Originally Posted by fjt

1. the Circlips are different.
2. the piston does not looks as pretty...lol
3. Usually Nippons have a hole right in the center of the piston

4. The piston should have a number engraved on the inside wall that says 22108. ALso the YCP logo is engraved on the inside wall of the piston

5. YCP Pistons comes on a Blue/white box..Nippons comes on a Yellow Box

yea dam that suxz i got nippon came in a whit box tho? i got a question what is so bad bout nippon pistons?

[91B20ED]

Originally Posted by gecko

yea dam that suxz i got nippon came in a whit box tho? i got a question what is so bad bout nippon pistons?

read #3 in the first post, he talks about it.

[fjt]

Originally Posted by gecko

yea dam that suxz i got nippon came in a whit box tho? i got a question what is so bad bout nippon pistons?

In a nutshell:
1. They arent made of the same material
2. weaker piston
3. will fail sooner..

I could be wrong but.. I have not seen yet a Nippon vitara piston holding in one pice and making over 350-375whp..
They break and MELT easily

[burnoutboy]

On the YCP is the whole piston teflon coated or just the sides?