Forged rods?

[jonbig]

In my mind there's two ways of looking at it. Naturally asperated and forced induction. NA the higher the compression ratio the higher the horsepower. If it's too high you run the risk of detonation/pinging. (same as running too much boost if FI). With FI, running a lower compression ratio allows the engine to handle more boost, which adds more horsepower. The hp gained by the extra amount of boost typically exceeds the hp lost by lowering the compression ratio. (example) If you're running 10psi on 9.1:1 compression ratio with detonation, you could possibly run 15psi on 8.5:1 compression ratio, have no detonation and make more power.

so basically what your saying is that for boosted engines, lower Comp.Ratio is the way to go. Forgive me for being a noob, but how exactly does one piston have a different compression ration then another? i mean in other words..what differences physically do the pistons have to make different Comp. Ratios?

ps how does have a lower compression ratio (we gotta come up with a universal abbreviation for that) allow us to run more boost?

 

[Wiggles422]

so basically what your saying is that for boosted engines, lower Comp.Ratio is the way to go. Forgive me for being a noob, but how exactly does one piston have a different compression ration then another? i mean in other words..what differences physically do the pistons have to make different Comp. Ratios?

ps how does have a lower compression ratio (we gotta come up with a universal abbreviation for that) allow us to run more boost?

compression ratio = CR

Usually the ideal CR for turbo cars is about 8.0:1 to 8.5:1. If you go any lower you lose a lot of power and that will greatly increase turbo lag bacause you won't have enough power to spool up the turbo.

The more room between the top of the piston (when it is at the top of its rotation, or Top Dead Center) and the bottom of the head (where the valves are) the lower the CR will be. This can be done in two ways.

CR can be altered by the connecting rods (the shorter the connecting rods, the lower the CR... and vice versa for higher CR) or it can be altered by the pistons. The "shorter" a piston is, the lower the CR.

 

[MSPRCRX44]

so we can stay on stock internals if its tuned right as long as we upgrade the rods?

 

[wicked]

price for set?

you should do a set like www.modernperformance.com does for the neon.they have complete bottom end kits and complete top end kits with top quality products.comes with forged pistons,connecting rods,bearrings,oil pump,wrist pins,and oil pan gasket.

just a thought.

do you guys carry;better head gaskets,ARP head bolt kits,water pump,timming belt,ect..........just wondering if I can get it all in one place.
doubt it,but please do tell me what you do have and prices please.by the way I am going with the 8.5

 

[Captain KRM P5]

so we can stay on stock internals if its tuned right as long as we upgrade the rods?

internals = pistons and rods

you can keep the stock pistons. the rods really are the weakest part of these engines.

as for the question about compression; you are basically 'raising' the compression in your engine when your turbo forces air into it. without the proper amount of fuel to match that air you get detonation, which = bad. by having lower compression you have the ability safely force more air into the engine, i.e - run higher boost.

 

[wicked]

price for set?

you should do a set like www.modernperformance.com does for the neon.they have complete bottom end kits and complete top end kits with top quality products.comes with forged pistons,connecting rods,bearrings,oil pump,wrist pins,and oil pan gasket.

just a thought.

do you guys carry;better head gaskets,ARP head bolt kits,water pump,timming belt,ect..........just wondering if I can get it all in one place.
doubt it,but please do tell me what you do have and prices please.by the way I am going with the 8.5

yup,I don't like to break things.

 

[Spooled]

You can also lower the CR by putting on a thicker head gasket (not necessarily the best way), or raise it by having the head milled.

 

[Bhamsan]

So how much will a set of forged rods for CR 8.5:1 be?

 

[HiBoost TS]

You are forgetting something very important which is the fuel you use. With 91 octane 8.5 to 1 is better, but with 93 octane then 9.1 is ok. If you run race fuel with above 100 octane, then you can run more boost safely, so it depends where you live and what fuel you can get.

Also the combustion chamber design makes a big difference. That is why Hondas and Acuras can take more boost than some other engines and don't forget that the stroke vs bore also is important . Larger bore vs stroke takes more boost but is lower in torque.

Our set up is $1,400.00 and includes the following:

Pauter Forged rods
9.1 or 8.5 :1 CR pistons
New piston rings
Head gasket
Cam seals
Wrist pin lock kit to allow the use of floating rods on stock pistons.


Juan

 

[Spooled]

You are forgetting something very important which is the fuel you use. With 91 octane 8.5 to 1 is better, but with 93 octane then 9.1 is ok. If you run race fuel with above 100 octane, then you can run more boost safely, so it depends where you live and what fuel you can get.

Also the combustion chamber design makes a big difference. That is why Hondas and Acuras can take more boost than some other engines and don't forget that the stroke vs bore also is important . Larger bore vs stroke takes more boost but is lower in torque.

Our set up is $1,400.00 and includes the following:

Pauter Forged rods
9.1 or 8.5 :1 CR pistons
New piston rings
Head gasket
Cam seals
Wrist pin lock kit to allow the use of floating rods on stock pistons.


Juan

Juan,

So is there anything else that is needed to switch over to these new internals? I just want to know if there would be an surprises like I would need some c-rings or something. That doesn't sound like a bad deal at all for the whole setup if that's right.

 

[goku4658]

is that basically everything we need? I'm new to any tuning besides basic bolt-ons and this my first FI car. I'd like to thank everyone for this highly informative thread.

 

[HiBoost TS]

That is all you need. The only surprises you can have is the rod bearings being worn out, but not likely in our "new engines" (low mileage)

It will include instructions in how to remove the middle piece between the oil pan and engine block as well as the head. This should be done by someone with good mechanical experience.

 

[hello2000]

Juan,

which is better if I go with your gt28rs upgrade, 8.5:1 or 9:1?

 

[goku4658]

You are forgetting something very important which is the fuel you use. With 91 octane 8.5 to 1 is better, but with 93 octane then 9.1 is ok. If you run race fuel with above 100 octane, then you can run more boost safely, so it depends where you live and what fuel you can get.

Also the combustion chamber design makes a big difference. That is why Hondas and Acuras can take more boost than some other engines and don't forget that the stroke vs bore also is important . Larger bore vs stroke takes more boost but is lower in torque.

Our set up is $1,400.00 and includes the following:

Pauter Forged rods
9.1 or 8.5 :1 CR pistons
New piston rings
Head gasket
Cam seals
Wrist pin lock kit to allow the use of floating rods on stock pistons.


Juan

Juan,

which is better if I go with your gt28rs upgrade, 8.5:1 or 9:1?

Going along the same lines as hello2000's question, would the kit you detailed above be totally compatible with an upgrade to the gt28rs? Sorry for the noobish questions.

 

[jeffmsp]

wow, $1400 for a built bottom end. I think you are going to be getting some of my nice canadian dollars in the near future (however long $1400 takes lol)

Juan, do you also sell preassembled bottom ends (ie everything all put together) or if i sent out a bottom end to you would you be able to assemble it with your internals and send back to canada, or can any local guy do the install fine?

 

[Spooled]

Juan,

I have never done anything internally on an engine, but I have many friends who are professional technicians. I don't think any of them have ever worked on a Mazda, but one is a tech at Roush. Keeping that in mind, how long would something like this take to do? This is my daily-driver, but I can manage a day of two without it (I get company cars often). Would I have to get the block machined to match the new slugs, or is this something that a couple of tech-friends and I can do over a weekend?

 

[spicynamja]

I know the install would be a PITA so how much would you charge me to install? I know you are near enough that I could drive there.

 

[HiBoost TS]

Going along the same lines as hello2000's question, would the kit you detailed above be totally compatible with an upgrade to the gt28rs? Sorry for the noobish questions.

It depends on how much boost you want to run. 8.5 to1 is more boost friendly than 9.1. I have 8.5 in my car and it works great. Up to 17 psi on 91 octane fuel. The car has performed very well at the track with no problems.

I would recommend to go with the 8.5 :1 CR. Even if you are not planning to boost much, remember that boost is addictive and you always want more and it will allow you tu run a more advanced timng curve for more power.

 

[wicked]

thats kinda costly for what you get,is the stuff made to order?
you should include bearings and head bolts for that price.

then I'd be in on it

 

[HiBoost TS]

thats kinda costly for what you get,is the stuff made to order?
you should include bearings and head bolts for that price.

then I'd be in on it

All parts will be in stock. The rods are in stock as well as all other parts. We are working on the pistons to keep them in stock.

Try getting a set of rods. It will take 8 to 10 weeks and you will have to pay in advance.

You don't need the bearings unless they are worn nor the bolts for the second use.