GSC S2 or S3 vs Kelford vs FP4r

[my98GST]

Built 2L 9:1cr 9200RPM limit
Beehive springs +1mm valves, JMF Race SMIM, PTE 6262 Turbo 700hp range.

Right now the head has some Web's in it and I'm looking to upgrade. I'm looking for real world experience with these cams. I honestly don't have a clue which direction to go as my last set of cams were BC 280's and I was pretty disappointed in them.

I'm not too too worried about streetability as the car does not get driven on the street much at all. Just wanting across the board results and power.

 

[viperlp01]

Kelford 280/276 would work well depending on fuel and the a/r of the turbine housing.

1-TX280 Camshaft Set - EVO 1-3 4G63 VR4 - Kelford Cams

 

[my98GST]

255 in tank, Bosch 044 in line, FIC 2150's, a1000 afpr -8 feed -6 return. its a .82 3" vband discharge.

Would the Forced Performance beehive springs work? Or would I need to get "high pressure" springs like the Kiggly or the recommended "KVS63-BTK High Pressure Beehive Spring, Titanium retainer kit

 

[spoolin ddub]

255 in tank, Bosch 044 in line, FIC 2150's, a1000 afpr -8 feed -6 return. its a .82 3" vband discharge.

Would the Forced Performance beehive springs work? Or would I need to get "high pressure" springs like the Kiggly or the recommended "KVS63-BTK High Pressure Beehive Spring, Titanium retainer kit

FP bee-hives won't be good for Kelford 280 or GSC S3's etc size cams. Those cams have to much lift. But the FP 4R,GSC S2, and kelford 272 should be ok.

 

[viperlp01]

I would go to the Kiggly HP springs. They are good for big lift, long duration.

 

[my98GST]

Thanks for the input and responses. Keep the responses coming. I'm very interested in seeing what the general suggestion is.

 

[finesse49ers]

I'm running, well WAS running a BB 6262 with GSC S2's. The S3's are designed for use on turbo's 67mm and up.

 

[viperlp01]

So the camshaft is designed around a compressor wheel size only? Interesting....

 

[phunny]

So the camshaft is designed around a compressor wheel size only? Interesting....

Yeah fool, oh and it's good for hp between 445.3 to 498.021

 

[LandSpeed-DSM]

Yeah fool, oh and it's good for hp between 445.3 to 498.021

Well, I think there is something to that honestly

There were some interesting articles in the last couple years about turbo cams including this one from multiple contributors, one of which being Kenny Duttweiler
Turbo Camshaft Guide - How to Select the Right Cam for Your Turbocharged Engine - Car Craft Magazine

My thoughts on why they would give a sort of guideline for turbo size is that it probably has a lot to do with the way they run the event splits and exhaust valve closing using a few assumptions about the turbo on a mass market cam.

The biggest one that comes to mind being the difference in boost:drive pressure ratio you get in a T4 frame 67+ mm turbo vs say a 58-60mm T3 frame turbo.

When it comes to timing the overlaps and exhaust closing event you can cam the bigger turbo, with a greater boost than drive pressure more like you would an NA cam. Including something like a <112* LSA, shorter intake duration with the exhaust valve open earlier and longer.

This is just my understanding, of course. I am hoping to have more information with the new setup now that I have a better backpressure sensor setup, pre/post turbine EGTs and two widebands to help me figure out what cam gear angle/camshaft setup the car likes on this new turbo configuration vs. what I can find from playing around with the S200sx a ways back.

I would be curious to see someone else's take on that sizing discrepancy though.

 

[viperlp01]

Unfortunately the dsm market is focused on "272" or "280" and not the actually specs of the camshaft and truely what they were designed for. Trust me I use to say the same thing a while back. When you learn how to read a cam card and pick a cam that works best with your setup is when you maximize your setup.

Edit in regards to landspeed:

Especially with the stock frame chargers using huge compressor wheels with at least a 2:1 back pressure you can't just pick a cam shaft off compressor wheel size. Same goes the other way when people bolt on HX40s with T4 17cm^2 housings. Smaller compressor wheel then some of the stock framed stuff but close to a 1:1 ratio.. Camshaft choice would be completely different between the two options above.

 

[LandSpeed-DSM]

Well it takes a lot of experimenting and time to pick up, frankly I still have a lot to learn as far as valve event timing.

Trying to pick up what I can from the Furd and Chebby guys, but they don't speak DOHC so I have to try and interpret.

What do you think of my assessment in the post above yours, John? Have I missed the mark, or might there be some merit there?

 

[RipperXX]

The Ford guys will be speaking DOHC well soon with that new 5.0 they have thats such a beast....Thats about all I could contribute to the thread as I'm going to be upgrading to a GSC S1 cam , DON"T JUDGE ME! I'm on a little MHI Evo III 16g, it's perfect for a street driven 16g car.

 

[LandSpeed-DSM]

Unfortunately the dsm market is focused on "272" or "280" and not the actually specs of the camshaft and truely what they were designed for. Trust me I use to say the same thing a while back. When you learn how to read a cam card and pick a cam that works best with your setup is when you maximize your setup.

Edit in regards to landspeed:

Especially with the stock frame chargers using huge compressor wheels with at least a 2:1 back pressure you can't just pick a cam shaft off compressor wheel size. Same goes the other way when people bolt on HX40s with T4 17cm^2 housings. Smaller compressor wheel then some of the stock framed stuff but close to a 1:1 ratio.. Camshaft choice would be completely different between the two options above.

Off the top of your head, if you had to make assumptions for the purposes of design a tiered set of cams.. like the S1's S2's etc.. instead of custom grinds, which will be my next stop after testing on the S3's I have now and my old custom ground cam from the last turbo I had, a 59mm..

What generalizations would start to base your valve events around for:

1.) 2.0, no head-work and manifold (Both I/E) TD06H 20G car

2.) 2.0, no head-work with big plenum/short runner intake and divided big tube (1 5/8") tube T4 manifold with something like a S300sx 66mm on it?

I realize that more details would change things, drastically in some cases.

But would you apply something along the lines of the hypotheses I posed in my initial post, factoring in other details to fine tune? That is what my experience and research has led me too and I'm always interested in other input on these things.

 

[my98GST]

Okay I see its pretty much came down between Kelford 272's and GSC S2's.. Which would benefit me the most and why? If I were to upgrade turbos later to say 6766/6765 what would still be my best bet so I wouldn't have to do cams again?

 

[turbo23]

Off the top of your head, if you had to make assumptions for the purposes of design a tiered set of cams.. like the S1's S2's etc.. instead of custom grinds, which will be my next stop after testing on the S3's I have now and my old custom ground cam from the last turbo I had, a 59mm..

What generalizations would start to base your valve events around for:

1.) 2.0, no head-work and manifold (Both I/E) TD06H 20G car

2.) 2.0, no head-work with big plenum/short runner intake and divided big tube (1 5/8") tube T4 manifold with something like a S300sx 66mm on it?

I realize that more details would change things, drastically in some cases.

But would you apply something along the lines of the hypotheses I posed in my initial post, factoring in other details to fine tune? That is what my experience and research has led me too and I'm always interested in other input on these things.

for #1, I'd probably use the comp 101200. works well with that long intake runner of the stock manifold, and has low overlap help fight off the 2:1 drive pressure. Works well with a wide variety of stock frame charger / stock intake combos.

#2: this requires way more info that what is listed; compression ratio, A/R, application.. stick or auto.. tire size etc...

 

[LandSpeed-DSM]

For purposes of discussion and control.. both would be on a stock compression in this case 7.8:1 like you would find in an molested 6-bolt. We're neglecting that the stock bottom end would come apart with an S366 on kill and rpm you'd turn to get the motor/cam into the meat of the compressor map and max it out.

Let's treat them both as drag cars, awd stick shift, 24.5" slick on E85

S300sx (91/79) would be in the T4 1.10 flavor.

Basically just looking to see what approach others would take when approaching cam selection if everything was comparable except the manifolds, cam and turbo... with the sort of manifold you'd expect on a large compressor T4 build. Drag style big plenum, short stack intake and then an equal length big runner divided exhaust.

Lets assume open downpipe on each and divorced wastegate dumps, so little added pressure to be multiplied across the turbine by its expansion ratio.

Build a sort of algorithm for cam choice based on those parameters, I suppose.

 

[SHEARER_TSI]

Jesus where are you guys on my thread about cams for use with an fp red????

 

[phunny]

Jesus where are you guys on my thread about cams for use with an fp red????

I was

 

[turbo23]

It takes me a bit to look at the whole package and come up with a profile that I feel will work best for the combination. So I'll give you some criteria that I normally look at.. On a drag specific car, I'll look at the compressor map to see what avalible airflow is, then figure out what the car weighs. From this I'll calculate a rough idea of trap speed. Then I'll calclate RPM through the traps based off of gear ratio/tire size/ and MPH. That will give me a rough peak rpm to build the cam around. Next things to look at would be intake runner length/plenum volume, compression, and A/R w/turbine flange size. Basically look to see if there is an issue with any of these aspects that wont work well with the target rpm, and change the cam accordingly. Also need to look at spool issue, say if its an auto w/stock converter, i'd back the intake duration back a touch to help get things moving. This is mostly for the intake cam. On the exhuast cam fuel type,compression ratio, rpm and turbine combination are the largest contributors. Fuels like E85 and meth burn different than say race gas or pump. By burning different I'm reffering to both burn rate, and temp. I'll take all these aspects and look at what cams are avalable, and find what is the closest to the numbers I want, or have a custom one ground.

 

[LandSpeed-DSM]

It takes me a bit to look at the whole package and come up with a profile that I feel will work best for the combination. So I'll give you some criteria that I normally look at.. On a drag specific car, I'll look at the compressor map to see what avalible airflow is, then figure out what the car weighs. From this I'll calculate a rough idea of trap speed. Then I'll calclate RPM through the traps based off of gear ratio/tire size/ and MPH. That will give me a rough peak rpm to build the cam around. Next things to look at would be intake runner length/plenum volume, compression, and A/R w/turbine flange size. Basically look to see if there is an issue with any of these aspects that wont work well with the target rpm, and change the cam accordingly. Also need to look at spool issue, say if its an auto w/stock converter, i'd back the intake duration back a touch to help get things moving. This is mostly for the intake cam. On the exhuast cam fuel type,compression ratio, rpm and turbine combination are the largest contributors. Fuels like E85 and meth burn different than say race gas or pump. By burning different I'm reffering to both burn rate, and temp. I'll take all these aspects and look at what cams are avalable, and find what is the closest to the numbers I want, or have a custom one ground.

That's encouraging to hear, as this is exactly how I picked the S3 to get started with before I find if theres a need for a custom grind.. except replace 1/4 mile trap with SCTA/ECTA timing lights

Thinking I will start with both straight up on the gears and then test with retarding both cams for more top-end. Somewhere along the lines of Intake -1/Exhaust -2 or 3, to increase over lap as well.. big turbine/high boost on E85.

Spool is not a concern for me. It's a low comp motor.. just a hair of 8.0:1, expecting to run boost deep into the 40s for a few miles at a time eventually. Aiming to keep EGT in the low 1300s/high 12s out the back door.

 

[my98GST]

So..... Lol.

 

[my98GST]

So can anyone else give me an idea which set of cams would be best for my setup and goals?

 

[LandSpeed-DSM]

Kelford 280/276 would work well depending on fuel and the a/r of the turbine housing.

1-TX280 Camshaft Set - EVO 1-3 4G63 VR4 - Kelford Cams

What he said^

with some kiggly springs and adjustable gears.

What turbine side? Pump gas or E85?

 

[bastarddsm]

Noone is going to agree, but I will say that the difference between a good cam choice and a poor cam choice is much less than you'd think. Probably less than a few percent. This isn't coming from a guess, this is actual dyno work on a big power turbo limited setup. We make about 1600hp out of a 76mm turbo, cam wise, best to worse was only 35hp.....

Run somthing middle ground and call it a day. Spend the rest of your time getting a good turbo setup/tune/chassis, and you'll go much farther.