2G Cam choice help

[Quent]

Hey my eclipse gst spyder is basically stock a apexi n1 exhaust and megan downpipe. I want a rough idle aggressive lope cam. But my car doesn't have alot of power (basically stock) . If I put gsc s2's or bc 280's will that hurt my car? I know the lower profiles like 264 and 268 is what I need but it doesnt have the choppy aggresive sound I want

 

[TuskeeTuner]

I know bench racing is bad but I have more questions. Would Kelford 264/260s work with a JMF Street and a "20G" sized turbo? Also pairing with a tubular exh manifold from a popular and well known fabricator. So far only the cyl head and turbo are the only parts finished right now. Car will mostly be used on the street once it's finally put together.

Conservative goal of 400-430 WHP on pump gas is all that's expected.

I'll fill out a profile once I start 'building' and designing some of my own installations.

I await your informed opinions.

 

[NOSLO2PT0]

Smaller cams work great for a small turbo like a 20g. I wouldn’t bother with an aftermarket tubular manifold if those are your power goals. Spend the $1000-1500 elsewhere. A stock 2g or even an FP manifold will work just fine.

 

[TuskeeTuner]

Smaller cams work great for a small turbo like a 20g. I wouldn’t bother with an aftermarket tubular manifold if those are your power goals. Spend the $1000-1500 elsewhere. A stock 2g or even an FP manifold will work just fine.

Money is already spent on the manifold. Just waiting for final delivery. I appreciate and understand what you're saying though... Power goals will be attempted on 92 octane PUMP. Trying to figure out a "good" cam+intake/exh mani+turbo combination(s).

Thanks for your time and input!

 

[Mello]

Conservative goal of 400-430 WHP on pump gas is all that's expected.

This much power at the wheels on pump gas alone will be hard to get with a 20G size turbo. You will probably need to help it with some ethanol or water/meth.

 

[NOSLO2PT0]

Money is already spent on the manifold. Just waiting for final delivery. I appreciate and understand what you're saying though... Power goals will be attempted on 92 octane PUMP. Trying to figure out a "good" cam+intake/exh mani+turbo combination(s).

Thanks for your time and input!

I was making around 400-425whp on 93 octane way back in the day. Never dyno’d the car. Just estimates off weight/ET. Car ran 11.50@120. My setup was this:

FP Green
FP2 cams (272 equivalent)
FRH intake manifold
Ported 2g exhaust manifold

Running about 25psi, tuning with an AFC.

 

[TuskeeTuner]

This much power at the wheels on pump gas alone will be hard to get with a 20G size turbo. You will probably need to help it with some ethanol or water/meth.

I understand that although I don't necessarily understand how hard this will be, I do recognize that it will be a challenge. Turbo is a KTS D645+TD06, 38mm ext wastegate and JMF recirculated ext WG housing. Goal is to select parts that allow engine to move air and not run tons of boost to make CFM.

Still leaning for Kelford 264/260, 264/268, or GSC S1 268s. I like the advertised lift of 11mm intake. Can always add or remove a little overlap with cam gears.

 

[TuskeeTuner]

I was making around 400-425whp on 93 octane way back in the day. Never dyno’d the car. Just estimates off weight/ET. Car ran 11.50@120. My setup was this:

FP Green
FP2 cams (272 equivalent)
FRH intake manifold
Ported 2g exhaust manifold

Running about 25psi, tuning with an AFC.

Thanks for the reply. Your past goals are impressive, and give me hope for mine.

 

[Boomdeeze]

My previous setup was on Kelford 264s, Evo 3 intake and FP manifold at 37 psi running a 3076, car ran a 10.7 on street tires. I wouldn't hurts your drivability for the sole reason of having the lope at idle, your turbo and future you will hate yourself for that choice! The Kelford 264s are great cams that flow well all around, those would be my choice.

The FP exhaust manifold is awesome and all you need if you are sticking to the stock mitsu flange turbo, my current setup is kelford 280s, Magnus V4, 3582, and the fp exhaust manifold running at 40 psi so the FP exhaust manifold goes a long ways.

 

[Canadian_CD9A]

I understand that although I don't necessarily understand how hard this will be, I do recognize that it will be a challenge. Turbo is a KTS D645+TD06, 38mm ext wastegate and JMF recirculated ext WG housing. Goal is to select parts that allow engine to move air and not run tons of boost to make CFM.

Still leaning for Kelford 264/260, 264/268, or GSC S1 268s. I like the advertised lift of 11mm intake. Can always add or remove a little overlap with cam gears.

Keep in mind that an unported DSM head doesn't flow very well past 10.5mm of lift. It will still pick up some power, but the returns will be marginal for that extra 0.5mm.

 

[NOSLO2PT0]

Keep in mind that an unported DSM head doesn't flow very well past 10.5mm of lift. It will still pick up some power, but the returns will be marginal for that extra 0.5mm.

Stock, unported heads have run 8’s. Do they flow as good as a Honda head? No. But with a big enough turbo, it will flow plenty.

 

[Canadian_CD9A]

Stock, unported heads have run 8’s. Do they flow as good as a Honda head? No. But with a big enough turbo, it will flow plenty.

Right, but he mentioned 11mm as a feature he liked, which doesn't really apply to the stock head. The lift isn't as much of a benefit to an unported head as an increase in duration and ramp rate and change in LSA if outright peak power is the goal.

 

[TuskeeTuner]

Keep in mind that an unported DSM head doesn't flow very well past 10.5mm of lift. It will still pick up some power, but the returns will be marginal for that extra 0.5mm.

Sure learning some good stuff here. I do have an unported 1g head...I asked for a slight polish but I guess the shop never got to it. I wasn't charged for it so oh well. Should I limit my choices to cams with LESS THAN 11mm since the head won't work as well?

 

[TuskeeTuner]

My previous setup was on Kelford 264s, Evo 3 intake and FP manifold at 37 psi running a 3076, car ran a 10.7 on street tires. I wouldn't hurts your drivability for the sole reason of having the lope at idle, your turbo and future you will hate yourself for that choice! The Kelford 264s are great cams that flow well all around, those would be my choice.

The FP exhaust manifold is awesome and all you need if you are sticking to the stock mitsu flange turbo, my current setup is kelford 280s, Magnus V4, 3582, and the fp exhaust manifold running at 40 psi so the FP exhaust manifold goes a long ways.

Thanks for your testament on Kelford 264s. How did they behave on the street: idle, vacuum/mani pressure, off-boost response, cruising 70mph on the freeway?

 

[Canadian_CD9A]

Sure learning some good stuff here. I do have an unported 1g head...I asked for a slight polish but I guess the shop never got to it. I wasn't charged for it so oh well. Should I limit my choices to cams with LESS THAN 11mm since the head won't work as well?

You don't have to - the GSC S2 and Kelford 272 work pretty well on an unported head and don't suffer much. Just keep in mind that you will need head porting to get the most out of an 11mm+ cam though. If you want something that's going to give you everything it has, without requiring additional modifications, stay a bit below. I like that the TX264 combination only runs 10.35 on the exhaust but has a quick ramp rate - it's going to be more responsive.

 

[NOSLO2PT0]

Just make sure you get a good dual valve springs setup if you get cams with an aggressive ramp rate. I don’t know of a single valve spring set up with enough seat pressure to handle an aggressive cam

 

[TuskeeTuner]

Just make sure you get a good dual valve springs setup if you get cams with an aggressive ramp rate. I don’t know of a single valve spring set up with enough seat pressure to handle an aggressive cam

Best discussion I've had in a long time about building DSMs. You guys really know your $4!t and helping me make considerations I otherwise wouldn't.

Bad news is I only have Crower's single spring with titanium retainers. Good news is the specs for the Crower springs are the same as the Kelford KVS63 single spring. They're both manufactured by PACALOY.

Last build I had (many years ago) used HKS 264/272. I guess those are like water compared to GSC S1s and Kelford TX264.

 

[jed344]

Either of those less aggressive cams would work well. I feel many people go to aggressive on cams. I don’t see the point of s cam that shines up top unless you have a set up and port work to use it. I run a S2. But I have ported head +1mm valves jmf race and a turbo that can flow above 8,000rpm.

 

[Boomdeeze]

Thanks for your testament on Kelford 264s. How did they behave on the street: idle, vacuum/mani pressure, off-boost response, cruising 70mph on the freeway?

Honestly they are great cams. My idle was set at 1k as that's where I liked it but vacuum was around 10-12 in/Hg, off-boost was good but I was running a 3076 and a 3582 so will be different than yours, cruising 70 you wont notice anything different from other cams.

 

[Canadian_CD9A]

I finally found the flow numbers to explain what I was talking about regarding the lift vs. flow numbers on the 2G head.

Look at the flow numbers of 0.400" lift (10.16mm) to 0.450" lift (11.43mm) - it goes from 227 to 229 cfm on the intake, and 183 to 183 cfm on the exhaust. Adding lift does nothing past 0.350" or so (9mm), it's done flowing. All gains here will be from duration, LSA and overlap changes.

Meanwhile, the ported 2G head in this example is showing gains all the way to the end of the test at 11.43mm. To recap, don't make your decision based on the lift figures if your head isn't ported. Duration, ramp rate and LSA are where the gains are. Even though I have a ported head, I got Jun 264s for my car. They are low lift at 10.50mm/10.50mm (0.413"/0.413") but they crank the duration up to around 225-228 degrees at 0.040", which is more than the HKS 280, thanks to the aggressive ramp rate. Something like the Jun 264 and Kelford TX264 combo are ideal for a stock head that wants to maximize a mild combo, or they're also great for a person with a ported head that wants to maximize response with a very strong midrange.

Manufacturer Part Number	Port/Vol Int/Exh	Valve Size Int/Exh	Combust. Chamber Vol	.100	.150	.200	.250	.300	.350	.400	.450	.500	.550	.600	Average
1G Ported​	N/A	-	N/A	-	-	-	-	-	-	275/-	-	-	-	-	-
1G Ported Mike +1mm valves​	N/A	35mm/31.5mm	N/A	87/78	-	169/166	-	230/208	-	257/227	-	270/239	-	-	-
2G​	N/A	34mm/30.5mm 3.37 No Pipe	N/A	80/73	-	155/146	-	211/181	-	227/183	229/183	-	-	-	-
2G Ported​	N/A	- 3.37 No Pipe	N/A	91/73	-	173/147	-	226/210	-	254/234	269/240	-	-	-	-

Stan Weiss' - Cylinder Head Flow Data at 28 Inches of Water -- DFW / FLW Flow Files for use with Engine Simulation Software

Cylinder Head Flow Data @ 28 Inches of Water -- DFW / FLW Flow Files for use with Engine Simulation Software

users.erols.com

 

[TuskeeTuner]

I finally found the flow numbers to explain what I was talking about regarding the lift vs. flow numbers on the 2G head.

Look at the flow numbers of 0.400" lift (10.16mm) to 0.450" lift (11.43mm) - it goes from 227 to 229 cfm on the intake, and 183 to 183 cfm on the exhaust. Adding lift does nothing past 0.350" or so (9mm), it's done flowing. All gains here will be from duration, LSA and overlap changes.

Meanwhile, the ported 2G head in this example is showing gains all the way to the end of the test at 11.43mm. To recap, don't make your decision based on the lift figures if your head isn't ported. Duration, ramp rate and LSA are where the gains are. Even though I have a ported head, I got Jun 264s for my car. They are low lift at 10.50mm/10.50mm (0.413"/0.413") but they crank the duration up to around 225-228 degrees at 0.040", which is more than the HKS 280, thanks to the aggressive ramp rate. Something like the Jun 264 and Kelford TX264 combo are ideal for a stock head that wants to maximize a mild combo, or they're also great for a person with a ported head that wants to maximize response with a very strong midrange.

Manufacturer Part Number	Port/Vol Int/Exh	Valve Size Int/Exh	Combust. Chamber Vol	.100	.150	.200	.250	.300	.350	.400	.450	.500	.550	.600	Average
1G Ported​	N/A	-	N/A	-	-	-	-	-	-	275/-	-	-	-	-	-
1G Ported Mike +1mm valves​	N/A	35mm/31.5mm	N/A	87/78	-	169/166	-	230/208	-	257/227	-	270/239	-	-	-
2G​	N/A	34mm/30.5mm 3.37 No Pipe	N/A	80/73	-	155/146	-	211/181	-	227/183	229/183	-	-	-	-
2G Ported​	N/A	- 3.37 No Pipe	N/A	91/73	-	173/147	-	226/210	-	254/234	269/240	-	-	-	-

Stan Weiss' - Cylinder Head Flow Data at 28 Inches of Water -- DFW / FLW Flow Files for use with Engine Simulation Software

Cylinder Head Flow Data @ 28 Inches of Water -- DFW / FLW Flow Files for use with Engine Simulation Software

users.erols.com

Thanks for the informative reply. I really am learning quite a bit and gaining more perspective on selecting parts for my (hopefully) build.

I'm definitely not selecting cams based solely on valve lift alone. If that were the case, I would have considered GSC's R2 stroker cams:
ADV DurationDuration @ 0.040"Peak Lift/Center Line/Intake274°236°/12.00mm lift/109°Exhaust274°/236°/12.00mm lift/115°

The Kelfords TX-264 and GSC's S1 cams happen to have advertised and measured durations that seem reasonable for a KTS D645/TD06 sized turbo with Mitsu housing, Morrison Fabrications's DSM manifold, and JMFab Street intake mani.

 

[We're on Boost]

@TuskeeTuner
Do you still have an E85 station up there around Everett somewhere?
Have you thought much about using E85, flex fuel?

 

[NOSLO2PT0]

The Kelfords TX-264 and GSC's S1 cams happen to have advertised and measured durations that seem reasonable for a KTS D645/TD06 sized turbo with Mitsu housing, Morrison Fabrications's DSM manifold, and JMFab Street intake mani.

What turbo is this close in size to? What kind of flow rate does the compressor wheel have?

 

[TuskeeTuner]

@TuskeeTuner
Do you still have an E85 station up there around Everett somewhere?
Have you thought much about using E85, flex fuel?

Thanks for the reply.
I don't know of an E85 station close by Everett but there's one in Tacoma. I have considered using E85. If/when I can find a car and get it running well, I can get parts ordered and installed.

 

[TuskeeTuner]

What turbo is this close in size to? What kind of flow rate does the compressor wheel have?

Thanks for the reply.
Comp wheel is one of those 11-blade/11-0 "20G" analog billet wheels. I have no idea how it flows but measures about 52mm x 72mm. It's considerably taller than the 20G wheel. If I don't like it I can always have it rebuilt with something else.

 

[We're on Boost]

Thanks for the reply.
I don't know of an E85 station close by Everett but there's one in Tacoma. I have considered using E85. If/when I can find a car and get it running well, I can get parts ordered and installed.

Ok I just called the 2 stations I know of in the area to ask if they still sell E85, and they do. The one near Everett is in Marysville. The other one is in Snoqualmie and that is the one I've been going to. But I haven't been there this year at all, because I'm still running on a bunch of E98 that I got from English Racing in May.
Just something to keep in mind I guess, if you have trouble making your hp goals with the 20G. And then if you did flex fuel you would probably find that E50 ~ E60 is plenty good enough when the gasoline fraction of your tank is actual 92 octane gasoline rather than the crap gas they put into E85.

Alternative Fuels Data Center: Alternative Fueling Station Locator