Thread: QR25 Two Intake Cam angles

Had to cut and paste because the formatting was annoying to fix.

The .25/.50/.75 is if you have the WRP or another modified cam gear like it to let you tune it as you wish.

Installing it at the 6th tooth around is the closest to stock overlap, although it is about 5* more overlap. I ran this with great success. Others who used the 5th tooth found it to be too much overlap and the majority of the burn hadn't completed (causing loss in low end torque) and greatly raised EGTs.

Unfortunately, the idea spot is going to be between the 5th and 6th tooth. I expect 5.25 or 5.5 would be ideal. Here are the explanation of the teeth I'm referring to.


^ This is just brain bling


I believe this is (c) BigJ



This is a WRP (dickhole) sprocket. If you use the 5th tooth with the +2, then you are at 5.25. +4* is 5.5 teeth. This is what I was refering to above. To get a 5.75 you would use the 6th tooth with the -2. I could be backwards on this part if someone will remind me. I remember WRP had his shit all fucking stupid and backwards (but I believe negative was less overlap, I can't remember.)

Oh yeah. don't do the 4th tooth ever. Do the 6th unless you are going to try 5.25.

Pimpsmurf, people runing the second intake cam on the 5th tooth saw a huge loss in low end torque as you said. running it on the right tooth shows what kind of gains? I'm fully bolted and wonder if I could not find some extra cheap horsepower.

Originally Posted by camirand16

Pimpsmurf, people runing the second intake cam on the 5th tooth saw a huge loss in low end torque as you said. running it on the right tooth shows what kind of gains? I'm fully bolted and wonder if I could not find some extra cheap horsepower.

Each tooth is like 16 degrees of angle. 5 is 21 degrees sooner opening. That is way too damned much.

6th was great for me. I can't tell you what gains were there because it was part of my last build. I ran 16+ psi on e85 and made somewhere above 425whp. I made 390 on 16psi at 5600 before the build on pump gas and meth (and runing out of fuel.)

Anyways, if one was so inclined, I would recommend tuning the WRP sprocket on a dyno using an EGT datalogger after you have tuned fuel propperly. Add overlap until the egts go up. I expect 5.5 or so will be ideal. The extra overlap (ie, exhaust opening sooner) will help turbos spool faster, increase exhaust pulse speed for na guys as well as decreasing detonation risks. Good shit. It isn't just about making power, although I think it would on it's own, but it allows you to make more power.

In the real world, it would be much cheaper to just get bc s2-s3 cams depending on your power level unless you get cheap dyno time and have an EGT and adjustable sprocket already.

this would be good for me because i have access to intake cams at work. i remember this from a long time ago but cant remember if anyone did this on n/a without a wrp sprocket. do you still have the pictures of the sprocket stock and where to go with it.

Originally Posted by 06chill

this would be good for me because i have access to intake cams at work. i remember this from a long time ago but cant remember if anyone did this on n/a without a wrp sprocket. do you still have the pictures of the sprocket stock and where to go with it.

it is already pictured above. Stock and WRP.

the pictures didnt come up for me yesturday

Moar info:

JWT C1 cams have the exhaust opening at 126.5, which is roughly the "5.75" tooth on the WRP sprocket. neet info! I thought it would be in there!

However, the JWT cams have a whopping 36.5* of overlap!! Stock is only 3* and the JWT S1 cams are 23. Pretty intense. This doesn't count the 20 some degrees that IVT adds in the low rpms (fades quickly to around 8). IVT doesn't do much, and a WRP sprocket (or the like) used to move the cam .25 of a tooth would add that 8* back. (provided you just plug the IVT oil supply port to block the oil flow.)

The 2 intake cam mod is .393" compared to .407" on the C1 cam, which isn't that far off. bigger than the S1's.

The 2 intake cam mod at 5.75'th tooth would open at 125 with 9* of overlap.
The C1 cam opens at 126.5 with 36.5* of overlap. WOWZER! It's all on the intake side really. They are adding a ton of overlap. IVT will still be adding some as well. They are claiming a 10hp gain when using a large exhaust and large tube header into a 3" collector (presumably with very short runners) and a free-flowing (read: short) 3" exhaust.

I wonder if they are losing power up top with these? I'm betting not. I'm betting it is extending the rpm range you can make power. If I build an N/A motor, I won't be reving past 7500. IMHO, 7500 is already dangerous without an 07 crank swap. Not that it is going to blow up instantly, but that it will wear the engine much faster. I'll also probably be using custom pistons with a longer I beam rod and higher wrist pin (in the 12.5:1 range). Like kojima did, but with HC piston profile.

I think with engine management, pistons, rods, cams, headwork, oil squirters, ARP headstuds, 07 HG and a custom intake and exhaust manifold, it will make in the 250whp range on e85. Then put 150 shot of staged direct port injection (2x 75 shots, 8 injectors) and it should be quicker than most.

I read somewhere that c1 requires plugging the cvtc to keep it static? Maybe Justin can chime in

Read about this alot and have a question.

On a turbo application of this, if you advance the intake side 2 degrees and the intake can on the exhaust.side 5 then the egt would be manageable?
Also could you run two exhaust sprockets with out a standalone and it just throw codes? Or would it go into limp mode?
And this would be done on a pnp head with a 5 angle valve job.