These Are The L15B Cams You've Been Waiting For! (and we can save you a bunch of money on them)

[Austin@Wunderladen Racing]

Hey everyone, we’re excited to share that Kelford has recently started offering L15B cams! We’ve used Kelford cams in other cars and have always good results so needless to say we are excited to see them supporting the L15B engine too. For anyone not familiar, Kelford has a great track record making some of the best cams for popular import engines such as the 4G63, 2JZ, RB26, K series, etc. I’ve looked at the profiles they’re offering and the specs are much more in line with what the L15B wants compared to other aftermarket cams on the market so I expect the gains to be pretty epic!

Kelford currently offers 3 different cam profiles for the L15B:

"EZ" Drop In: The drop in profile is meant for use with the stock valve springs with a max redline of 7000RPM. Most of the gains will be in the mid and high RPM range. Lift and duration is 7.8mm/246° for the intake and 8.5mm/250° for the exhaust.

"A" Stage 1: The stage 1 profile is meant for use with higher flowing turbos, and like the drop in cams most of the gains will be in the mid and high RPM range. Lift and duration is 9.5mm/262° for the intake and 9.5mm/268° for the exhaust. The stage 1 profile requires upgraded valve springs, Kelford has a spring and retainer kit that is stable to 8500RPM.

"B" Stage 2: The stage 2 profile is meant for use with large turbos. Most of the gains will be in the high RPM range. Lift and duration is 11.2mm/268° for the intake and 10.7mm/272° for the exhaust. The stage 2 profile also requires an upgraded valve spring and can also be paired effectively with Kelford's spring and retainer kit that is stable to 8500RPM.


I’m sure many people will be asking what would be the best profile for their application and here are my thoughts. The drop in profile is best for anyone on a stock turbo and has no headwork done, stock valve springs etc. The stage 1 profile would be my recommendation for anyone who has put a mildly larger than the stock Si turbo on their car (W1, R365, GC, etc.) and upgraded valve springs. If you have an upgraded turbo but don’t want to change springs the drop in profile would still make for a solid improvement. The stage 2 profile I would only recommend for people running larger turbos than the ones mentioned for the stage 1, with a ported head and upgraded valve springs.

So, pricing. We are going to be doing a group buy for these, price will be contingent upon how many people buy in. The standard MSRP for these cams is $995, our group buy pricing will be as follows:

• 5-10 people = 10% off ($895)
• 10-15 people = 15% off ($845)
• 15+ people = 20% off ($795)

To sweeten the deal we’ll also be offering the same discount structure on Kelfords springs and valve stem seals for anyone who orders the Stage 1 or 2 profiles and would like those items. The spring package they are offering is specific for the L15B and uses the correct length spring seats to keep valvetrain geometry where it needs to be as well as uses a high quality spring steel for the springs. The valve stem seals they offer are made from viton and polyacrylic which is a high temp elastomer that can handle more heat than the stock seals, it’s a “while you’re in there” part to change. The seals go for $40 for a full set (intake and exhaust) and the springs and retainers sell for $595, if we reach the max discount those become $32 and $475 respectively.

We have been talking with Kelford about this for a bit now and are fairly ahead of the ball. Since these cams are so new Kelford hasn’t made any production batches yet. This means we will be getting these made and will be the first in the country (potentially the world) to get these cams. With that said, we are anticipating an early-mid September arrival for the order.

In order to get locked into the group buy I will need you to PM me with the following (copy and paste to keep it easy please):

Name:
Cam Profile:
Springs (yes/no):
Valve Stem Seals (yes/no):

Other than that we will be requiring a $150 nonrefundable deposit up front and the remainder will be due when we get them in from Kelford. I will keep the OP updated with who’s locked in so everyone can see what discount level it is sitting at. You’ll be able to lock into the group buy until August 11th.

Who's ready to make more power with their L15B?!

Edit: Cam specs vs stock per Kelford

 

[GrDeleto]

Question. What benefits would this have on a stock turbo? Just wondering.

 

[Austin@Wunderladen Racing]

Question. What benefits would this have on a stock turbo? Just wondering.

More mid range and top end power. I've never seen a stock turbo 4 cylinder make less power with cam upgrades on stock turbos. Evos, Subarus, Ecoboosts, Mazdaspeeds all make more power on the stock turbo with a better cam.

OE cams are rarely power optimized for the stock turbo. The manufacturer has to consider fuel economy and emissions as well as power targets so that often means power takes a backseat to the other.

 

[LBP]

Any mention of fuel lobe improvements?

 

[GrDeleto]

More mid range and top end power. I've never seen a stock turbo 4 cylinder make less power with cam upgrades on stock turbos. Evos, Subarus, Ecoboosts, Mazdaspeeds all make more power on the stock turbo with a better cam.

OE cams are rarely power optimized for the stock turbo. The manufacturer has to consider fuel economy and emissions as well as power targets so that often means power takes a backseat to the other.

Im gonna guess a custom tune is required cuz lol.

 

[Austin@Wunderladen Racing]

Any mention of fuel lobe improvements?

Good question. I will ask Kelford. I know they have increased fuel lobes on other platforms so I don't see why they couldn't here. Main thing would be figuring out how much to add.

Im gonna guess a custom tune is required cuz lol.

The car should still run fine with the drop ins but you'll want a tune to get the most from them. This is better answered by a tuner familiar with the platform though, I don't know how picky the stock ECU may or may not be with different cams. We've done cams with no tune change on other cars without issue but I'm not going to say that will be the case here for certain.

 

[Boosted_01_R]

Kelford makes quality cams. Ran them on my 2JZ for years. They should sort out the HPFP lobe before selling them honestly. Drob has said @KTuner can work with the higher lift HPFP lobe on the Hondata cams.

Manufacturing cost won't change with a larger HPFP lobe and adds a lot of value for the customer. Honestly buy a Hondata cam and measure, that how the industry goes....

What's the OEM lift and duration on the IN / EX cams ?

 

[speedyserg]

What were the gains and what did they tune on? Would be nice to see their testing/final numbers

 

[Austin@Wunderladen Racing]

Kelford makes quality cams. Ran them on my 2JZ for years. They should sort out the HPFP lobe before selling them honestly. Drob has said @KTuner can work with the higher lift HPFP lobe on the Hondata cams.

Manufacturing cost won't change with a larger HPFP lobe and adds a lot of value for the customer. Honestly buy a Hondata cam and measure, that how the industry goes....

What's the OEM lift and duration on the IN / EX cams ?

Good to know KTuner can utilize a larger fuel lobe.

You're correct that it won't change cost but it would certainly but a delay on production for them. We are not going to buy Hondata cams to measure them.

I can ask Kelford to see what they measured. Was also going to send a set of cams to a friend that has a cam doctor at his work and get a second source for the stock profile. But that will also take time.

What were the gains and what did they tune on? Would be nice to see their testing/final numbers

I've not seen them post any dyno numbers. I would fully expect these to make more than Skunk2 cams, so more than whatever Skunk2 has for number gains. Gains are going to be very conditional though, and depend heavily on how what other mods the engine has, so it won't always be apples to apples.

 

[Boosted_01_R]

Good to know KTuner can utilize a larger fuel lobe.

You're correct that it won't change cost but it would certainly but a delay on production for them. We are not going to buy Hondata cams to measure them.

I can ask Kelford to see what they measured. Was also going to send a set of cams to a friend that has a cam doctor at his work and get a second source for the stock profile. But that will also take time.

Well if you figure out a lobe height, I'm interested, but not looking to buy twice... Yeah will delay production but your putting out a better product.

Cast or Billet ? Material ? None lobe surfaces looks pretty smooth, so I assume billet...

Cams will make more power and you best sellers will be drop in and stg1. Work with Phearable, let's see some proper data with the GC+ turbo. Good luck

 

[speedyserg]

I've not seen them post any dyno numbers. I would fully expect these to make more than Skunk2 cams, so more than whatever Skunk2 has for number gains. Gains are going to be very conditional though, and depend heavily on how what other mods the engine has, so it won't always be apples to apples.

In order to verify any gains you have to have a static control condition.

Stock cam vs drop in cam - same everything except proper tuning for both aka max power both can produce

That's the only way you can verify gains - actual apples to apples.

Plotting a bone stock untuned car vs a tuned cam car would be silly so just as 4Piston did with the TR2s you tune both as best you can and see the delta between the two. The TR2s typically make about the same power as stock cams do minus 3psi - on the same boost gains are upward of 40whp+ over stock

Control for boost/engine temps/iATs etc so you can isolate what the cams are gaining vs other factors that effect power.

These 10th Gen heads flow like garbage so cams at least allow them to carry the power higher/longer even on a stock port - I gained a good 50 to 70whp on a race port without cams so I'm sure the L15B7 would gain about 2/3rds of that or so with similar work. Cams would be a no brainer on a built/ported head especially for increased fuel demand.

I'm sure kelford knows this so was curious about their testing numbers/setup.

Anyone have a link to a ported L15B7 head vs stock head dyno? I don't follow them much but would be curious to see the gains there. Maybe Ososik has some data on his setup since he is one of a handful to go 600+whp with an L15B7

The L15B7 market is even larger than the k20c1 market so if these cams are good they will sell alot of them for sure.

 

[Austin@Wunderladen Racing]

Well if you figure out a lobe height, I'm interested, but not looking to buy twice... Yeah will delay production but your putting out a better product.

Cast or Billet ? Material ? None lobe surfaces looks pretty smooth, so I assume billet...

Cams will make more power and you best sellers will be drop in and stg1. Work with Phearable, let's see some proper data with the GC+ turbo. Good luck

We're not the ones making these cams so ultimately it's Kelford's decision on what gets changed. I agree that a larger fuel lobe would be a good selling feature but it's also something that will require a custom tune which may steer some people away from it. We may recommend it as just a change for the stage 1 and 2 profiles and leave the drop ins as is since the intended market for the stage 1 and 2 will have mods that already require a custom tune.

I am not sure whether they are cast or billet cams but that won't affect their function. Cams have to be surface hardened regardless of what they're machined from, but yes, they do appear to be machined from billets and Kelford does sell billet cams for other applications.

In order to verify any gains you have to have a static control condition.

Stock cam vs drop in cam - same everything except proper tuning for both aka max power both can produce

That's the only way you can verify gains - actual apples to apples.

Plotting a bone stock untuned car vs a tuned cam car would be silly so just as 4Piston did with the TR2s you tune both as best you can and see the delta between the two. The TR2s typically make about the same power as stock cams do minus 3psi - on the same boost gains are upward of 40whp+ over stock

Control for boost/engine temps/iATs etc so you can isolate what the cams are gaining vs other factors that effect power.

These 10th Gen heads flow like garbage so cams at least allow them to carry the power higher/longer even on a stock port - I gained a good 50 to 70whp on a race port without cams so I'm sure the L15B7 would gain about 2/3rds of that or so with similar work. Cams would be a no brainer on a built/ported head especially for increased fuel demand.

I'm sure kelford knows this so was curious about their testing numbers/setup.

Anyone have a link to a ported L15B7 head vs stock head dyno? I don't follow them much but would be curious to see the gains there. Maybe Ososik has some data on his setup since he is one of a handful to go 600+whp with an L15B7

The L15B7 market is even larger than the k20c1 market so if these cams are good they will sell alot of them for sure.

What I was getting at is we are not advertising a certain power gain because power gains will vary depending on what is done to one car vs another. Yes we could do a before and after as an example for power gains but everyone else won't necessarily see the same exact gains. Also, it's not something we have the time for right considering Kelford's production timeline and there not being any available to send to us before they go into production.

I am waiting to hear back from Kelford about if they have any results they can share as far as gains go. They're on the other side of the planet so getting a response isn't always instant.

As for ported heads I'm not aware of anyone who's done one and posted results. I spoke with Luke over at 4P about doing ported heads but their interest wasn't too high in it because of how small the heads are they have to retool their machines with smaller tools to do an L15B head and then retool it again to go back to doing K series heads.

For what it is the stock ports aren't all that bad. There's always room for improvement on a stock head but it isn't atrocious by any means. Head porting and cams go hand in hand, running stage 2 cams on a stock port head won't give nearly as good of gains as they would on a ported head. Likewise, a ported head with stock cams isn't going to be world changing but there may be some mild gains.

 

[Oddwayne]

I can’t imagine the L15s taking well to revving much further than 7-7.5k due to the long stroke over square setup. Even with balancing the bottom rotating assembly, I don’t see the engine lasting long revving to 8500 often. But I guess you’d have to see where power starts to fall off. May not even need to rev close to 8500

 

[Austin@Wunderladen Racing]

I can’t imagine the L15s taking well to revving much further than 7-7.5k due to the long stroke over square setup. Even with balancing the bottom rotating assembly, I don’t see the engine lasting long revving to 8500 often. But I guess you’d have to see where power starts to fall off. May not even need to rev close to 8500

Smaller components can be spun faster because less mass means less force. Yes the L15B is undersquare but that doesn't mean it can't be revved high. The 89mm stroke isn't anything crazy long, K24s have a 99mm stroke and reliably rev to 8500 and those use a larger, heavier crankshaft, rod and piston. Piston speeds are mainly influenced by stroke and rod length.

The K24A has a 99mm stroke and a 152mm rod. Rod ratio = 1.54
The L15B has an 89mm stroke and a 141mm rod. Rod ratio = 1.58

As you can see the rod ratio is higher in the L15B than the K24, which means lower piston acceleration and more favorable for revving high. Having smaller pistons also helps due to reduced weight but also means there is less rocking in the piston at TDC and BDC which is good for keeping wear low.

Of course that's just the bottom end. The reason the factory redline is only 6500RPM on the L15B is because the stock turbo falls off after that point. The cylinder head and turbo have to be able to support these speeds or it's pointless to rev that high. With proper cam profile, head porting and a larger turbo these engines will live fine at speeds above 8k RPM, the whole package just has to be set up properly to support it.

 

[GrDeleto]

Smaller components can be spun faster because less mass means less force. Yes the L15B is undersquare but that doesn't mean it can't be revved high. The 89mm stroke isn't anything crazy long, K24s have a 99mm stroke and reliably rev to 8500 and those usea a larger, heavier crankshaft, rod and piston. Piston speeds are mainly influenced by stroke and rod length.

The K24A has a 99mm stroke and a 152mm rod. Rod ratio = 1.54
The L15B has an 89mm stroke and a 141mm rod. Rod ratio = 1.58

As you can see the rod ratio is higher in the L15B than the K24, which means lower piston speeds and more favorable for revving high. Having smaller pistons also helps due to reduced weight but also means there is less rocking in the piston at TDC and BDC which is good for keeping wear low.

Of course that's just the bottom end. The reason the factory redline is only 6500RPM on the L15B is because the stock turbo falls off after that point. The cylinder head and turbo have to be able to support these speeds or it's pointless to rev that high. With proper cam profile, head porting and a larger turbo these engines will live fine at speeds above 8k RPM, the whole package just has to be set up properly to support it.

Think it's the same reason why the k20c doesn't rev beyond 7k.

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