Hi guys! I have problem with my setup. On attached dyno you can see my old setup - the red line.

Setup

H22
Stroke 95mm
88mm 12,5:1 CP pistons
Skunk2 Pro1
EuroR manifold
Hytech replica header
70mm TB
IDs 1050x
Nonported head

New setup is black line.

4Piston H22 ported Head
Skunk2 Pro2
Oversized 1mm intake valves
Ported and gutted OEM intake manifold

Car is tuned on dyno, afr is good, we rotated cams, move vtec to 4000 and 6000 and on the graph is the best we can tune.
Because head has oversized intake valve and V2V clearance i had to advance exhaust cam. On dyno we advance/retard cams and no solution for torque drop. Angle separation has to be 5 degrees.

Whe is there drop in torque after VTEC? Why has low cam higher torque then high cam?

Is the head overkill? Pro2 are too big or small for this head? Problem with intake?



Car feels strong and everything seems ok. But dyno comparison is not satisfied for me :-)

Thank you!

 

I'd look at the header and intake manifold, something isn't flowing enough air to keep up when the cam changes

 

I can change intake and see. But why header? In last setup it was sufficient. Thank you.

 

Hmm... old setup is clearly better even in low cam and because it is Pro1 vs. Pro2, then the biggest differencein there is the new head(work). Restrictive exhaust can mess up cylinder head flow.

 

Intake manifold is different too. OEM gutted manifold vs EuroR. In last setup exhaust seems to be sufficient. But im not experienced tuner.

 

I too would try a different header. Not a fan of Hytech's designs.

 

What ?!? Which brands/products do you prefer ?

 

https://dtrheader.com/

 

This!

Same stroke, Same bore w/ 14.5:1 cr, and RLZ head with stock size valves and M5, made 330whp! in 2015!!! (This was with a custom header and custom sheet metal intake manifold and 90mm TB, and Pro3's) Your build will make 300whp still, or damn near it. 300whp on e85.

That combination needs to breathe!!! The ideal intake manifold for this combination other than custom intake manifold would be H2K intake manifold adapter plate and a K series side draft (not center feed) Skunk2 ultra race with plenum spacers and 90mm TB. It will carry the power further as well. You will lose torque anytime you go with a race port head. Your powerband will move further to the right. This setup needs to be revved to 9,000-9,500.

Jack Myers will custom make you a header and it will out perform anything you can get your hands on. Ask anyone in the all motor game.

 

Ups, i dont need to rev so high - max 8500. This is street car and reliability is important for me. Why that 90mm throttle body? From logs and map sensor the TB is not limiting factor. I know that ported head will lose torque but i didnt expect so much at 6000 :-( If i put on my car the setup you reccomend could expect power in midrange too? Im looking for some gains in midrange, im not going for maximum numbers at 9500 rpm.

Thank you for hints and sorry for my english!

 

I think I understand now. This wasn't intended to be a drag build. However, you chose the wrong combination of parts for your goal. Type S camshafts and stock head with ported manifold will be where you want to be. Your cams choice and cylinder head choice are designed for high revving, later power band.

If you revved the setup and purchased the parts to allow the engine to breathe, torque will follow suite but you will not get stock like powerband and torque, everything moves to the right but it's still there. As the power increases the torque will be there but it will not be at low rpm with CNC Race head, oversized valves and pro2s. This isnt a midrange combo.

 

What is the safe rev limit for this stroker? I would like to have strong reliable engine(20 thousands kilometers lifetime). What is a compromise? I would like to remove that power dip - 30WHP.

My next plan is to put back Pro1 cams couse i thing that my Pro2 are alot out of centerline because 1mm oversized intake valves. Ideal cams setup is -0,5I and +2E now a have to have -0,5I nad +5E to have 0,03 V2V clearance.

 

Safe rev limit is dependent upon rods, rods bolts, and valvetrain. If these are all upgraded, you are good to go to their limit of failure. I'm not a believer of less than ideal rod/stroke ratio means you cannot rev an engine out. 9,000 will not hurt this engine.

 

Thank you. What do you think about lower torque then before? Can it be bad degreed cams due to oversized intake valves and moved exhaust centerline?

 

Wrong cam choice/head package. Switch back to your pro1 if need be. However, you are only revving to 8500rpm and are concerned with mid range I would suggest switching to Type S cams. Again my friend, pro2's make good power, pro 3's even more. BUT, with midrange sacrafice over smaller profile cams. That's to be expected. The 4 piston head was likely one of their high rpm, drag style cylinder heads which was designed to live at 10k plus rpms. I would have contacted them and explained you were after midrange power and they would've hopefully sent you in the right path.

 

Thank you for your time. I wrote 4P but without answer. This head is advertised as streetable so i thought that it will be nice for 5000+ rpm powerband. I will put back Pro1 cams and see what happend. Last setup was very nice and my dream is reliable 300hp NA so i bought bigger cams and ported head and still has reliable engine. My mistake...

 

pro 2 instructions say dont use 1mm oversize valves...whats u compression on ur engine? same on pro 1?? or less??

 

Is Danny still building custom headers ? I tried to reach him a few years back to get one for my K-Series and couldn't get any response at all. I own and currently use BOTH a HyTech and a DTR/SSR header... both are excellent quality and work exceptionally well. I will be using an ASP on my K-Series EM1 project coming up and it appears to be on par with HyTech and DTR/SSR. Time will tell.

 

On Pro1 was 12 now is 12,5:1 Yes you are right S2 say not to use OS valves but alot of people use theese cams with OS valves and has 300HP. And a lot of cams makers seys dont use OS valves because people dont degree them and dont check clearances. In my setup is something mismatched cause that dip in pover after vtec is on. I know that some so big intake and custom header can make 300HP but i will be happy with 270 but better midrange to max 9000rpm

 

nono u dont understand..whats ur actually compression on each cylinder? 270psi???

 

Check v2v and p2v. Degree and check clearances. If they are good to go, you can run any cam, anytime, anyplace.

 

we had 2 years ago v2v issue on pro 2 cams and lost compression with 1mm oversize valve.

 

Yes. V2V contact will cause that.

 

IDK why people try to run huge cams with oversize valves.

You run into this exact problem, and you have to dial them back negating any small advantage you might have gotten from the valves anyway.

 

Yes Danny is back full time, although he never really left, I actually got a header made by him a few years ago.

But yeah as of 2020 he is back in it to win it, hit him up if you need something.