The reason for asking is that I got a set of new forged pistons here and they have 25 mm comp height. Hi there thought I'd let anyone out there know that wossner pistons stated std are not exactly standard fitted forged rods apr bolts bearings and h beam rods dyno printout was 230bhp with a new turbo turns out there not std but actually low compression pistons ie 150psi per cylinder comp ratio end up 8. As the piston travels up and down the cylinder, its base opens and closes the intake port as it passes. RS Machine - RS Spec 84mm Pistons High Compression for Honda B20 Engine. 5 parts of that 6. modifying your engine for boost Turbocharging or supercharging any engine increases the strain on all of the engine components. Valve cut outs also included, let us know your valve size. 5:1 Compression Ratio, 86mm Bore for the Honda / Acura K20A, K20A2, K20Z1, and K20Z3 Engines View detailed images (1) Supertech Pistons are manufactured in Argentina with technology transferred from European manufacturers. "Let's first look at the job of the top compression ring," DiBlasi explains. If the plan calls for serious nitrous, boost, or rpm, and bulletproof is what you are after, a 2618 piston is the right choice. Ring sets are available to fit standard and over-size pistons. This piston would not stand-up well to high boost. Starting with the engine at idle, slowly increase engine speed to 3,000 RPM, engine vacuum should be equal to or higher than idle vacuum at 3,000 RPM. The main differences between EJ255 and EJ257 that EJ257 uses new low compression pistons (compression ratio is 8. 003 the 4032 pistons are. 945" Pin Diameter and 6. The "boost valve" is a valve that increases the compression damping, mainly low speed but it will also affect the high speed to some extent. Forged, low compression pistons (7-8:1) are the best choice for performance applications. I ran flat-top cast pistons in a small block Chevy street/strip car for years with no issues. If your vehicle has been running roughly or losing power, there may be a lack of pressure in one or more cylinders. 5 to 1 compression, JE pistons, Pauter Rods). Please don't get testy with me because I didn't search the forum and this info is out there somewhere. Hypereutectic piston. your octane is gonna dictate how much boost you run much more than your piston choice. RallySport Direct also carries a great selection of sleeves from the ever popular Darton company. I had a Cobalt SS turbo and increased the boost a little. 0:1) pistons. Simply put, the higher the VE, the more air you can cram into the cylinders, and the more power the engine can make. The pressure from the higher air mass will break the ring lands on the pistons at about 13 psi. The piston rings in your car's engine are responsible for controlling oil pressure and regulating engine oil consumption. What is the horsepower difference between the two sleds and is the motor with the stock higher compression ratio stressed more than the motor with the lower compression ratio?. Running high compression with boost is stupid for a street car for one thing. 0:1 compression Mahle pistons intended for higher boost levels. Miller Performance is proud to offer some of the best quality performance pistons available for your M52, S50 or S52 engine. It is ideal to change compression ratio according to the load condition. For roughly 4 decades now, Ross Racing Pistons has met the global racer demand, for the most advanced forged pistons in the racing industry. There are tooltips over each input to tell you which values are affected by this input. Pro Circuit developed their High Compression Piston with the intentions of satisfying the need of your motorcycle's thirst for more power. I just told them I want to put a blower on the car to make 500 at the wheels. Page 1 of 6 - 14:1 Compression Pistons for 202 to 210 - posted in Engine: Hi All, Just asking for advice on 14:1 compression pistons for the 202 engine. High EGR rates were used in order to reduce the. I have been told i may have a or some stuck rings. Hyperteutectic pistons are most likely your best choice for a high performance street or mild (no nitrous) racing engine. People lower the compression which makes it harder to start. To avoid this costly and time-consuming job, we've created our Rislone Ring Sealer and Compression Engine Repair product. Decide on a final effective compression, and work your way back through the formula to find your maximum boost level: ((effective compression / motor compression) - 1) x 14. 0055” Bore x. Automotive performance pistons are manufactured in flat-top, dome or dish configurations—but such a variety in crown design doesn’t suggest that engine builders will always have a choice. Effective compression is the sum of the static compression, plus the additional compression added to the cylinder by a turbo or super charger, or any other forced induction tool for that matter. compression ration is 8:1 on 1. Normal 240 sx has 9 to 1 compression and should be limited to 7 psi boost. Infiniti will be the first company to market a variable compression engine. Piston ring sets must be properly fitted to the piston and cylinder. The 04-05 TRX's only had 10. IMPORTANT: If 351 pistons are used with a 400 crankshaft then the top of the pistons will slam into the valves and ruin the whole engine the first time you turn it over. Replacement Cost of Piston Rings. We discuss dish, dome, and flat top design considerations. That's a subtle but very important difference!. JE Pistons - Sport Compact: JE Pistons are specifically engineered for extreme applications up to, and including, professional competition. 0L connecting rod/forged piston combination offers less reciprocating mass than the 4. A compression ratio of around 18. 6:1 which is pretty low, so if i was about to put a Vtec head from let say B16A or B18C, can i boost this motor that im gonna get with high boost because of the low compression pistons. Higher than stock compression pistons for AMC 360 ????? Wondering if any one know's of any NEW higher than stock compression ratio ,cast or hyper( Not Forged ) pistons for a 360 ? i can only ever see the stock pistons in various oversizes which are about 9. To avoid this costly and time-consuming job, we've created our Rislone Ring Sealer and Compression Engine Repair product. Along with a dedicated line of in-stock pistons, we specialize in the manufacturing of custom, high-end, forged aluminum Import and Domestic piston applications, for use in high horsepower motorsports. By Mike McGlothlin It’s no secret that the majority of Americans are more accustomed to gasoline engines than diesels. Racing pistons, performance pistons, piston rings, custom piston, Diamond Racing provides high performance racing engine pistons and products for all your performance racing needs. The stock pistons are fine for stock engines. It does this by opening or closing the waste gate as needed. Porsche is developing a variable compression engine, a puzzle that has been tried by many but is not yet possible in the automotive industry. But if all you are doing is changing pistons you will need to turn up the boost 3-4psi just to make the same power as you are now. If I was towing all of the time and running a lot of boost from the turbo I would do it. Speedmaster has become a leader in its field, built on a long term consistency of being a specialist in aftermarket automotive components. Of the variables, the most important is cam timing which has a dramatic effect on your "dynamic" as opposed to your static compression ratio. results of boost ECR [effective compression ratio] on my 427+0. The Volvo B21FT engine does not have a fuel system with a lot of extra capacity to support great amounts of horsepower without leanning out (lean mixtures mean quick death to a turbo engine). For 13:1 theoretical compression ratio the top volume is 450/12 = 37. A gasoline piston engine that can dynamically change its compression ratio —that is, the amount by which the piston squeezes the fuel-air mixture in the cylinder—has long been a holy grail of. I guess I need these questions answered before I purchase pistons so I can purchase a set which will lower my CR to what is required. 0-1) with press fit pins are recommended for applications up to 12 psi of boost. Factory cast pistons are not recommended but may be used in very low boost (3-5lbs. It turns out it is an odd ball piston with 18. doesnt work that way. However, if it is too high this can lead to serious knock-related engine problems. Someone else will have to chime in about exact numbers, but I know that with JUST a TT HG, or JUST TT pistons, the compression is near perfect for boost. But now my friend has a set of pistons available that would boost it up to 10-1. What options do I have at the High compression pistons - Polaris RZR Forum - RZR Forums. Compression ratio is worked out by dividing the volume above the piston when it is at TDC into the volume above the piston when it is at BDC. i am currently considering buying a VL commodore (with turbo conversion) and the owner claims it has a steel crank, oversized valves, polished head and 60 thou oversized pistons. Factory Cast Pistons may be used in low boost applications (under 5 psi of boost). Resurfacing can be used to make a small compression ratio change, but since the actual length of the rod changes slightly due to heat expansion and due to strain, you need to make sure you don't cut off too much material. As the piston travels up and down the cylinder, its base opens and closes the intake port as it passes. Most Pro Tru pistons use a 4032 alloy, however big block pistons and certain small blocks designed for nitrous or boost receive the stronger 2618 alloy. 5" is the effective piston displacement plus the final top volume Effective displacement is then only 5. Factors that influence the compression ratio include: fuel anti-knock properties (octane rating), boost pressure, intake air temperature, combustion chamber. Take an N/A engine that runs at a 12:1 compression ratio and it's happy. All low compression motors make less power off boost then of course the power comes in when the higher boost is ran. Choose your compression ratio accordingly. JE Pistons has announced the release of a new lineup of lightweight FSR pistons for high compression Small Block Chevy 350 and 400 engines. Does anybody have any experience about high compression pistons in O-300? Ten years back there was a one 170 in Finland with hc pistons, but the funny part is that nobody knew before they overhauled the engine with normal pistons. The dome unfortunately can't be milled down much as it's quite thin. GM LS Asymmetrical FSR Dome STD Bore: 4. What brand pistons are trustworthy out there for turbo applications? So far i've found JE and Wiseco brands What compression ratio to use (normally running pump gas which is 91-93 in my area with the ability to dump in some race gas or E85 if I want to have fun)? How far should I if at all bore out the cylinders for the new pistons?. Lower compression will sacrifice out of boost power, spool time, and power/torque per pound of boost. Forged low compression pistons (7. Low readings could also be very late valve timing or worn piston rings. Ok, I seem to remember that with forced induction, it is better to have a lower static compression ratio (< 9:1) and rely on boost to obtain the optimal total compression. Attempting to combine a high static compression ratio and elevated boost levels is a. 5:1 arias pistons and stock rods with a greddy kit on 8 psi. I think it might actually surprise alot of you compression freaks. 00 USD; RX1- Apex Pistons $570. FOR YOUR COMPRESSION RATIO WITH THESE PISTONS PLEASE SEE THE CHART BELOW. Gas nitrided top ring: Superior combustion sealing, strength and wear. I'd like to know what is an acceptable boost level under these conditions, turbo is t3/t4. Going from 9. As you know, when the engine gets too hot, its pistons can get heat seized, because high temperature makes the diameter of the pistons get bigger and thus the cylinders become too small for them. Polk confirm this, as just 2. Imo, reduced compression pistons are a mistake with idi engines. I am a fan of high compression. To do so, you can either machine these through the main journals like certain factory oil squirters are or install an aftermarket squirter kit. Gas nitrided second ring: Superior strength and wear. With the proper fuel system and related engine components, an effective compression of 16:1 to 18:1 should be more than workable. 5:1 was my recommendation to weller for guys wanting to run up to 15psi and still have a snappy bottom end with quick spool. Numbers were similar to that IIRC. The compression ratio typically used for a passenger car diesel engine lies in the range between 15 and 16. modifying your engine for boost Turbocharging or supercharging any engine increases the strain on all of the engine components. 5:1 compression For your 2nd generation 2007-2010 N14 MINI Cooper S models including R56 Hardtop R55 Clubman R57 Convertible. I found out my 1994 with a 2000 3. Piston fed boost ports are a bit more tedious to install, but they have numerous technical advantages over "reed valve added" boost ports. They have dual keystone rings to help control the higher boost level. 945" Pin Diameter and 6. 0:1) pistons. These pistons are set up at 9:1 compression. From looking in my cummins manual the non turbo engines had this comp ratio. 10 over pistons along with the. 8:1 CR and that is without considering the block. However,there are several variables that cause that question to be more or less abstract. 0L MR20 DDT gasoline engine (the VC-Turbo) at the September 2016 Paris Auto Show. I think it might actually surprise alot of you compression freaks. 0:1 low compression turbo pistons. Ready to build that motor for some real power? Time for some forged pistons that will hold up to the higher demands of increased boost levels. STD Bore: 84mmPart #BoreOversizeStroke(mm)Rod(mm)C/D(mm)Head CC'sC/R With. 098" Rod Length. The kit includes piston rings, piston pin, and clips (uses stock replacements). Retailed new for $1000. Alright guys, I've been playing on all the stickies and have searched for over an hour. 6 2V or 4V, and 5. 8 bore Wiseco pistons from LJMS for my 5. Raising the compression ratio pushes the molecules closer together and improves the amount of fuel that is ignited. The piston sits just 0. These can then be fitted with a tighter piston-to-bore clearance, due to reduced expansion characteristics of the 4032 material. Without an effective combustion seal, of course, these gases would leak around the sides of the piston, resulting in a power-robbing. In this environment, the higher compression ratios, highest boost or heavy nitrous usage necessitate the higher tensile strength 2618 aluminum alloy. Those only have a 15. These 14cc dish pistons gave me a static More Info » Texas Bounty Hunter P/M 411, 5x ProMod Champion has used CP-Carrillo for the last five years, with a 0% failure rate. I personally wouldnt go down to 8:1. "Let's first look at the job of the top compression ring," DiBlasi explains. Racing pistons, performance pistons, piston rings, custom piston, Diamond Racing provides high performance racing engine pistons and products for all your performance racing needs. 1:1 compression. Wiseco is one, but they do not stock pistons for the H22A (have to be fully custom). 015” High Boost 30lb+ Gas, Alky, E85 Bore x. 1:1 compression combined with the boost if I tune the car to run on e85? I figure if I ever have to take a roadtrip to a place where it is unavailable I can take the blower belt off and run on premium. 5 to 1 (mk4 headgasket). 9:1 in the SOHC. 8:1 CR and that is without considering the block. “RACE-GAS ULTRA is the first product we have released since the release of RACE-GAS Race Fuel Concentrate in 2013. Forged pistons recommended for all applications. Now we are thinking about a little boost for the engine. Click here for a compression calculator. You actually need lower compression ratio in your case if you are going to run high boost. 1 were as standard comp ratio for bam engine is 186psi!!!so only good with an agu head and. Boost displacement about 8%, and torque similarly, then boosts CR, which adds MORE torque, etc. power range? is this car your only car?. 75:1 compression and modest OD on the blower to start. This part should fit your vehicle. Porsche is developing a variable compression engine, a puzzle that has been tried by many but is not yet possible in the automotive industry. That reduces the compression ratio momentarily, allowing for more turbocharger boost and more power. Boost levels above 12 psi should generally be avoided even with racing fuel on a 9. (boost / 14. Compression ratios and squish clearances are matched to work with premium pump gas. A camshaft with a large duration (300+) can allow a normally aspirated. I would just get some flat top pistons. The downward thrust of the piston that causes the crankshaft to rotate is affected by net combustion pressure, which is influenced by boost and compression ratio. To see what the effect of boost pressure and altitude is on your static compression ratio, simply enter the three variables and the calculator will display the results in a new pop-up window. I know many hyper piston engines that have thousands of street miles and alot of track time on them pushing 10 or more lbs of boost. The low-compression pistons featured a sizable dish to drop the compression ratio down near 8. Dome Pistons Opposite in concept to the dish pistons, these bubble in in the middle like the top of a stadium. Since 1968, Diamond Racing has been producing the highest quality racing parts around. i saw a post where a guy was running high compression with stock rods and boost and bent all 4 rods. Low readings could also be very late valve timing or worn piston rings. Higher compression pistons may cause detonation and heating problems and are not recommended on gasoline applications. 0L Coyote engines. Scat 4340 Forged Steel Crank (1)(2) Scat 4340 I-Beam Forged Steel Rods ARP 8740 7/16" Rod Bolts SRP Pro 4032 Forged Aluminum Pistons (3) Premium 8620 Steel Wrist Pins 1. 5:1 and the lower 9. 340 Compression Height Pistons utilize. Who is correct?. Technician B says a cylinder leakage test should be performed on all cylinders. 20 Oversized $550. weight, you are limited on what you can hit the track with at the launch. Lower compression will sacrifice out of boost power, spool time, and power/torque. The compression seal provided by your piston rings against your cylinders and pistons needs to be strong. You could argue that pressure during expansion is the most important, because that is the cylinder pressure pushing on the piston to produce power. In the last 10 years one of the biggest changes here at VPD has been the increased power available from our normally aspirated engines. At each level of additional boost, new issues for engine configuration develop and need to be addressed such as engine management, connecting rods, pistons, and head studs. Gotta love those forged pistons! I'm excited to see the horsepower and throttle response changes. Ideally you want a low compression ratio of around 8. The dyno charts show the solid increase in both bhp and torque achieved simply by slipping in these new pistons (use your existing piston rings if in good. Lead don't follow what people say, high compression and boost can go hand in hand it's just that the H22 motors were designed for NA hence the FRM sleeves for less piston to wall friction, lighter pistons, etc. Performance LSx and LTx Piston Sets. 5mm (237cc). The OEM 4AGZE pistons have proven as a good choice. I'm going to guess that your 1 point increase in compression 9actually 1. 5 Cubic Feet of air pushed into that SAME 120 PSI TDC Cylinder Pressure ?? Is this correct ?? IF so, THEN I finally understand why lower compression with more boost is better, as you get more REAL AIR in there. Compression ratio that is too low will result in an engine that is a bit sluggish in off-boost operation. Forged Pistons Are Stronger And Longer Lived Than Cast Pistons. 5:1 arias pistons and stock rods with a greddy kit on 8 psi. Does anybody have any experience about high compression pistons in O-300? Ten years back there was a one 170 in Finland with hc pistons, but the funny part is that nobody knew before they overhauled the engine with normal pistons. Conversely, a domed piston increases compression. If you did higher compression pistons and lower boost, you might only get 1. If you drive on boost more of the time then you might want a low comp engine. I can't comprehend how this is possible without the engine melting, what do you need to do to make a. 0T FSI Volkswagen. I'd like to know what is an acceptable boost level under these conditions, turbo is t3/t4. Supertech Pistons, with this alloy, have withstood up to 42psi of boost, with alcohol, without any problems. it gave me a ratio of 7. Does anyone know of any links to high compression pistons for a 1500X stock bore on either side of the pond. 5mm) Bore at 10. However, if it is too high this can lead to serious knock-related engine problems. 020" over 3. The Morbidelli 125 twin road racer is a rotary valve engine. Valve cut outs also included, let us know your valve size. i would like to run the titest clearances possible, and i know that the trade of is strength for lower clearances. The state of California and other states with similar laws and regulations prohibits the use of some parts on emissions vehicles. 0-liter EcoBoost four-cylinder engine uses a quick spooling and durable BorgWarner K03 turbocharger to achieve full boost by 2000rpm. It's just safer at higher boosts. Just be sure to confirm that total deck clearance is at least. 0:1 compression pistons,. A balance must be found between emission output and full load performance when deciding upon a compression ratio. Otherwise, different pistons will have to be ordered, or the cylinder head will have to be surfaced milled to reduce the combustion chamber volume and boost the CR. Feel free to comment, and please check out our new website! www. 00 USD; Viper 2016 Carrillo Pistons $550. High horsepower and fast timing or stock timing is a killer to pistons. The new “hollow dome” pistons feature a 2618 alloy forging with a dedicated undercrown design that closely follows the shape of the dome and valve pockets for maximum weight reduction. If I was towing all of the time and running a lot of boost from the turbo I would do it. Please enter your desired user name, your email address and other required details in the form below. You would have a problem with 11:1 on 93 without running boost, I wouldn't run more then 10:1 on 93 pump gas. But now my friend has a set of pistons available that would boost it up to 10-1. Will sell them for $1000 FIRM. If you can not get a good compression gauge to perform the above test it is OK and I will just use my best judgment on what I do for your finished head volume. compression ration is 8:1 on 1. Since 1968, Diamond Racing has been producing the highest quality racing parts around. 3 points) is going to net about 10% increase in power, all other things being equal. Compression ratio. Be smart and do it once. Naturally Aspirated or Light Boost. 10psi on 9. 3L/325 Pistons and get Free Shipping on Orders Over $99 at Summit Racing!. Ring sets are available to fit standard and over-size pistons. 10psi on 9. 5:1 compression, as well as 12. It's a problem with older high mileage engines. When discussing muscles involved in the pedaling motion of cycling, most people think of quadriceps and hamstrings. 0 to 1 for forced induction. When a vehicle has compression problems, there is less engine power, reduced fuel economy, and the engine may also burn oil. 040" composition gasket would be throwing away free compression. Anything is possible though. JE Pistons has announced the release of a new lineup of lightweight FSR pistons for high compression Small Block Chevy 350 and 400 engines. 5cc Eat sleep BOOST nothing to see here, move along. Compression ratios and squish clearances are matched to work with premium pump gas. In Reply to: What is "quench"? What is a "quench area" Why is it good? n/m posted by body on June 21, 1998 at 10:09:42: Quench, or squish area is typically the flat area on the top of the piston that's almost level with the top of the block deck. We keep between 25 to 40 sets of 944, 944T and 968 Turbo and Naturally Aspirated Piston Kits on our shelves. It's a trend that does not stick well with idi 4000-4500 rpm diesels. modifying your engine for boost Turbocharging or supercharging any engine increases the strain on all of the engine components. What happens is the spark plug tips melt away and pistons get burnt and melt too. They are aftermarket forged piston manufacturers that use Nikasil friendly rings. The high stock compression ratio means that you will be FIGHTING detonation with anything but the MINIMAL boost. 00 USD; Viper 2016 Carrillo Pistons $550. I would say that keeping it to at least a static compression of 9. Let's say your compression calculates out to be 10. To avoid this costly and time-consuming job, we've created our Rislone Ring Sealer and Compression Engine Repair product. So im wondering if im getting higher compression pistons, like 9:1-9. high compression vs. 5cc dish (for 9. However, few literature report their effects on cyclic variation. 5 to one would be best unless you are really going to shove a lot of boost through there. We now start inputting compression related information into our dyno software. -We stock many different variations. What The Heck Is Variable Compression, How Does It Work, And Why Does It Matter?! which helps the engine tolerate more boost and make more power. I am wondering if I can run stock 10. It just seems like cramming boost into such an engine without lowering the compression ratio and whatever other internal modifications are needed is a recipe for disaster. Turbochargers increase pressure in the combustion chamber, making the mixture more prone to detonation. In most cases, these will directly replace the stock pistons. 5:1 to 9:1 is recommended for boost levels of 8-10 psi. I don't know, but on the LS motors it matters on the material of the piston, factory piston on a LS are a Cast hypertutectic so they are at. If the compression increases, your piston rings are bad. 8-liter factory turbocharged Buick Grand National engine. If you start pushing boost higher then the turbo is over spinning and just super heating the charge. The width of the CR500RE boost port is quite wider but I didn't open the hole to the full width of the CR port. Factory cast pistons are recommended but may be used in very low boost (3-5 lbs. 015” PISTON RING INSTALLATION INSTRUCTIONS CLASSIC RACE & AP PREMIUM STEEL RING SETS GENERAL GAPPING RECOMMENDATIONS. Power output is maybe irrelevant as the engines will differ but maybe throw it in if you know it. Personally I am running about 9. Do you want full boost at 2500 RPMs or are you willing to wait and make big HP further down the RPM band. Opposed-Piston Engines with Variable Compression Ratio. Lower compression pistons will allow higher boost levels on lower octane ratings with less chance of knock and cylinder detonation than higher compression ratio pistons. The "boost valve" is a valve that increases the compression damping, mainly low speed but it will also affect the high speed to some extent. For safeties sake I would aim for a mild CR. As for pistons, don't change them unless the old ones are badly damaged and the piston to wall clearances are to high. Rather than cram a cookie cutter setup down your throat, BC offers you a choice of custom piston made to any desired bore size and compression ratio. 5:1 arias pistons and stock rods with a greddy kit on 8 psi. Make Model Year Engine Audi TTS MK2 (2009-2015) 2. Some of the F-1 engine builders were convinced that a cam profile with LESS lift/duration was better, with the cam JUST meeting the max lift over a very short period of time, was the key. This piston would not stand-up well to high boost. Factory Cast Pistons may be used in low boost applications (under 5 psi of boost). CP pistons are compatible with oversized valves and high lift camshafts. I was talking to a Top Alcohol Funny Car racer the other day and they only run around 12-1 compression static, and try to put in 50 plus pounds of boost. Flat tops and domed pistons increase compression of the cylinder. But if the compression ratio is excessive, an engine is vulnerable to detonation – the uncontrolled, spontaneous combustion of the air/fuel mixture in the cylinders. The LF3 is the most powerful V6 ever from General Motors, it is also the most power-dense six-cylinder engine in the midsize luxury segment. Compression ratio. 125" LSX Ring Packaged Designed for 1. 20 pounds of boost. Additionally, the limit becomes lower for turbo engine that intakes compression air. The pressure from the higher air mass will break the ring lands on the pistons at about 13 psi. I have a low compression motor (18:1) and would have to think twice to do it again. If you start pushing boost higher then the turbo is over spinning and just super heating the charge. you may wanna make your goals a little more clear. Not all values are verified and may have varied results base on casting flaws, ect. They flow more than cathedral-port heads, but not as much as LS7 heads. I am only going to replace the rods & pistons because I have to when boosted. 0mm Lightweight Ring Set Clevite 77 "H" Series Main & Rod Bearings Complete Assembly Internally Balanced. 7 = 150 PSI. Factors that influence the compression ratio include: fuel anti-knock properties (octane rating), boost pressure, intake air temperature, combustion chamber. 015 head gasket, which will push the compression up to 9. There are tooltips over each input to tell you which values are affected by this input. This piston would not stand-up well to high boost. Lower compression pistons would be better for increasing boost pressure, but higher compression engines are more efficient at making power when off boost, and need less boost pressure to make the same power. Do you want full boost at 2500 RPMs or are you willing to wait and make big HP further down the RPM band. This is a discussion on high compression and boost within the Forced Induction forums, part of the LSx Technical Help Section category; Originally Posted by mistermike Here's the deal with compression and boost, to clear up some blatant misinformation in earlier posts. Machined valve pockets provide additional valve clearance when used with higher lift camshafts. A thicker gasket will lower the compression slightly, and a thinner gasket will boost the compression slightly. Includes a set of 4 Pistons, Rings, and wrist pins. If you don't have a compression gauge, then you can either purchase one or take the car to an auto repair shop and have them test the compression for you. 0T FSI Audi A4 B7 (05. We offer a range of TechWorks engineered pistons to match your performance application. A Dome Top piston will effectively raise an engine's compression ratio, making them the ideal type of piston for medium to higher performance engines that may be using power adders (such as nitrous). 015” PISTON RING INSTALLATION INSTRUCTIONS CLASSIC RACE & AP PREMIUM STEEL RING SETS GENERAL GAPPING RECOMMENDATIONS. “RACE-GAS ULTRA is the first product we have released since the release of RACE-GAS Race Fuel Concentrate in 2013. 060"overbore. The main piston is a one-size-fits-all deal for the most part.