284 -276 schrick cams instead 284 264

[lucam3evo2]

Hi all,

II know it is a topic already dealt with but I thought that every engine with different specs has requirements

mi evo 2 after rebuild engine:

2.3 cc
Evo 2 TB
11.5 mahle motorsport , (with pocket)
Valve m5, 38,5
50/50 Evo2 collector with supersprint street
In port head 29.5 mm (by John)
Schrick street springs,
Cams: 284 and 264. (104-100),
Evo 3 injectors 300cc
Alpha N, airbox.
New oil pump
New water pump
New full distribution

I got 254 hp on dyno now the car has great strength even at mid-range !!!
I want to move on to the next step in the cams. 274 ex in your opinion is it worth it or is it better to leave 264?
would the difference be minimal ?
if i should also increase the fuel pressure or are the evo 3 injectors enough?
what timing you reccomended ?


P.S I state that I have decided not to go for the schrick 292
thank you

[Ironhead]

I ran 284/276 for years, and it is a great combination. But I think the difference from 284/264 would be very subtle/minimal. You might see a slight difference on the dyno, but I doubt you would notice it while driving.

[1990m3]

I do not believe you will see a significant change by only swapping the exhaust cam. I would probably leave the motor as it is now unless you want to make a big cam jump. But, since you do not want to go to 292/284 I think it sounds like a strong and healthy motor. Drive it and enjoy.

[Anri]

Hi Luca,

Before you continue buying parts I would suggest to make sure you are using a proper Dyno and proper readings which are not inflated or unreal low. I know I know a Dyno is a very ill subject....but so far Dyno-Jet has proven to be the most consistent without being very moody as I have experienced with other chassis dynos.

We assume BMW Factory don't lie you take a healthy bone stock US E30M3 192(SAE) crank hp to Dyno-Jet it makes around 164RWHP. I have done several stock US E30M3's including my E30M3.

Knowing this information when you build your hi performance S14 then you will see the real gains from factory numbers.

If memory serves me well you are from EU ? not from USA. Most european if not all dyno's do read Crank HP aka (BHP). Never been fan of this way nor I will because the power losses has been calculated in odd way. A friend from Germany who tuned his stock E39M5, after the tune it came up to 390rwhp...which is absolute impossible from stock engine, just tune !!!!

After knowing your curve and real HP gain from stock you can have better approach to your final desired target.

You mentioned 245hp I assume it's crank ?

Regards,
Anri

[lucam3evo2]

thank you all.

@Anri
yes I am European (Italy)
the hp are at crank (253)
any comments are appreciated

[Anri]

Hi Luca,

Thanks for posting the dynochart. I knew it was going to be in the BHP or crank HP. I am a bit confused with the reading, not sure if I can see torque curve ?

The main issue is that we dont know what a stock 2.3 makes on the same dyno. In your case is difficult to determine the gains from stock. Some dynos calculate 18-25% drive train losses which brings the BHP very hi...Hub Dyno's are extreme sensitive on gearing and differential changes....on the S52 we have tuned on DynaMite there is 18rwhp difference between 4th and 5th gear... Dyno-Jet does not care if its on 4th or 5th gear...

In your case the dyno you are using is nothing more than a tool to improve the power by adding performance parts and tune them, before and after.

More often than ever hi performance S14 engines start with mild build requests by the owner and then shortly after the engine is ran owner is ready to up the power.

Abstracting the number, looking at the HP curve it would be nice if the pick power comes slightly earlier so that you don't have to chase the revs every gear near the rev limit.

Regards,
Anri

[lucam3evo2]

Anti,
I hope to find the dyno chart of the first test. It made 200 hp but unfortunately the engine was out of phase. In fact the valves touched the pistons and that's why I rebuilt the whole thing.
After running in it made 247 hp and then 253 ..
The only small doubt is the net drop after 7000 (I have the rev limiter at 8000). It is true that the cams timing is set more for mid-rpm torque but in other dyno charts I also read max power at 7200-7400.
I forgot: I have differential of the 320is 3.46 instead of the 3.15.
Your advice is welcome

[stevesingo]

Hi Luca,

Thanks for posting the dynochart. I knew it was going to be in the BHP or crank HP. I am a bit confused with the reading, not sure if I can see torque curve ?

The main issue is that we dont know what a stock 2.3 makes on the same dyno. In your case is difficult to determine the gains from stock. Some dynos calculate 18-25% drive train losses which brings the BHP very hi...Hub Dyno's are extreme sensitive on gearing and differential changes....on the S52 we have tuned on DynaMite there is 18rwhp difference between 4th and 5th gear... Dyno-Jet does not care if its on 4th or 5th gear...

In your case the dyno you are using is nothing more than a tool to improve the power by adding performance parts and tune them, before and after.

More often than ever hi performance S14 engines start with mild build requests by the owner and then shortly after the engine is ran owner is ready to up the power.

Abstracting the number, looking at the HP curve it would be nice if the pick power comes slightly earlier so that you don't have to chase the revs every gear near the rev limit.

Regards,
Anri

Ref the bolded. Yes it does. Tyre losses (the greatest losses from flywheel to road) are directly proportional to road speed. Choose a higher gear on a Dynojet and the measured WHP will be lower. Want the biggest numbers out of a Dynojet, choose the lowest gear without wheel spin. By the by...

The dyno posted above has conducted a coast down measurement of tyre losses. Which is at least an attempt to quantify the losses, it is not totally accurate as there is no load on the tyres, so the losses measured are only speed related. The measured loss of approx 45hp at 120ish mph is a little high compared with with other similar types of dyno, but this is hugely influenced by the way the car is strapped down, rear toe and the tyre pressure, and if it is a single roller or twin roller dyno.

All tuning shop type dynos are flawed to different degrees. The key thing is to think of it as a tuning tool.

There is a wheel HP measurement of 215hp, which seems pretty strong to me, add to that a slightly higher than typical losses, it begins to look a little high.

Volumetric Efficiency (VE) is directly related to torque/litre - better cylinder filling = more torque. If we take it that a good NA 4valve/cyl engine will make about 80lbft/lt (VE of 105%), an exceptional engine 85lbft/lt (VE 112%) . A good 2.3 should have about 184lbft, exceptionally 196lbft. On the graph at 5750rpm we have 220hp. 220/5750*5252=201lbft. 201/2.3=87lbft/lt. To me that seems too high given the compression of 11.5:1 and pump fuel.

That is is not saying Luca did a bad job. The difference between a good engine and an exceptional engine would be a OEM backed engine development program matching head flow to cam timing to compression to intake length and header length. What we are all doing is piecing together off the shelf parts to get the best we can within our modest budgets.

Back to the original OP question. By changing to more cam duration, we may get a small increase in torque/lt. The larger effect is being able to fill the cylinders at higher rpm. Torque stays basically the same, power increases as we make the torque at higher rpm.

Prof Blair and Associates is a good read: http://www.profblairandassociates.co..._to_basics.pdf

[stevesingo]

I took the liberty to plot the power in to excel to make a torque curve.

All within the margin of error of my eye sight.

[lucam3evo2]

Hi
Not being a fan of the quest for absolute hp, I also love to use it to perfect the engine and delivery.
I am reminded that my tires are no longer too soft and tended to skid during testing. (maybe with Steve we have already learned about it) however in a few months I will test with new tires.
just to try to have a better grip and refine the performance in safety since I will also have to configure the phormula ks4 (anti-knock sensor)

[Anri]

Ref the bolded. Yes it does. Tyre losses (the greatest losses from flywheel to road) are directly proportional to road speed. Choose a higher gear on a Dynojet and the measured WHP will be lower. Want the biggest numbers out of a Dynojet, choose the lowest gear without wheel spin. By the by...

The dyno posted above has conducted a coast down measurement of tyre losses. Which is at least an attempt to quantify the losses, it is not totally accurate as there is no load on the tyres, so the losses measured are only speed related. The measured loss of approx 45hp at 120ish mph is a little high compared with with other similar types of dyno, but this is hugely influenced by the way the car is strapped down, rear toe and the tyre pressure, and if it is a single roller or twin roller dyno.

All tuning shop type dynos are flawed to different degrees. The key thing is to think of it as a tuning tool.

There is a wheel HP measurement of 215hp, which seems pretty strong to me, add to that a slightly higher than typical losses, it begins to look a little high.

Volumetric Efficiency (VE) is directly related to torque/litre - better cylinder filling = more torque. If we take it that a good NA 4valve/cyl engine will make about 80lbft/lt (VE of 105%), an exceptional engine 85lbft/lt (VE 112%) . A good 2.3 should have about 184lbft, exceptionally 196lbft. On the graph at 5750rpm we have 220hp. 220/5750*5252=201lbft. 201/2.3=87lbft/lt. To me that seems too high given the compression of 11.5:1 and pump fuel.

That is is not saying Luca did a bad job. The difference between a good engine and an exceptional engine would be a OEM backed engine development program matching head flow to cam timing to compression to intake length and header length. What we are all doing is piecing together off the shelf parts to get the best we can within our modest budgets.

Back to the original OP question. By changing to more cam duration, we may get a small increase in torque/lt. The larger effect is being able to fill the cylinders at higher rpm. Torque stays basically the same, power increases as we make the torque at higher rpm.

Prof Blair and Associates is a good read: http://www.profblairandassociates.co..._to_basics.pdf

Hi Steve,

Thanks for you reply.

Ref the bolded. Yes it does. Tyre losses (the greatest losses from flywheel to road) are directly proportional to road speed. Choose a higher gear on a Dynojet and the measured WHP will be lower. Want the biggest numbers out of a Dynojet, choose the lowest gear without wheel spin. By the by...

As I said from the begining Dyno is a ill subject...If see a Dyno operator or a Tuner who does tune or doing a test per your example I will politely ask for the car to be off the dyno and look for some one else. On a Dyno-Jet I work with the car sits every time on the same tire pressure, same strap tension, G265 4th 1:1 5th 0.83. The example and model you build is to "cheat" and manipulate the system. I hate cheating on the dyno and appling tricks. I never described this way of making a pass on 1st or 2nd gear were the pass is very short or spinning tires and this is good way to fool any dyno.

After have done over 100+ dyno passes on the Dyno-Jet my experience is that on 4th 1:1 and 0.83 5th the diffenrce is 1-2hp and that is hard to find is it either because the engine gets more heat soaked or the gear ratio change...Next week I have S54 dyno and i will pesonllay try to see on the same dyno-jet I use if I do pass on say 2nd 2.53ratio or 3rd gear 1.66ratio, I have never done a test with such a short run. I personally do Tune on a Hub Dyno because a load can be applied for tuning purposes and then I verify my numbers to same Dyno-Jet I use. But on Hub dyno there is significant variation in power if passes are down on 3th vs 4th vs 5th.

Volumetric Efficiency (VE) is directly related to torque/litre - better cylinder filling = more torque. If we take it that a good NA 4valve/cyl engine will make about 80lbft/lt (VE of 105%), an exceptional engine 85lbft/lt (VE 112%) . A good 2.3 should have about 184lbft, exceptionally 196lbft. On the graph at 5750rpm we have 220hp. 220/5750*5252=201lbft. 201/2.3=87lbft/lt. To me that seems too high given the compression of 11.5:1 and pump fuel.

This is complete separate subject that we should not go there because we will need the info you are seeking. I was/am reserved to ask more personal question about head CFM flow, what headers etc as you and I can see the head has been done by the owner of the forum you are moderator of. In Luca's build I would have done different approach such as valves cams etc..but this engine started life as what we see on the build sheet.

My single point to help Luca's further up the power is to ensure how far is he from OEM bone stock (DiN) EU E30M3 on the same dyno same conditions tire pressure strap tension etc..and then look for chokes, or parts which are restricting further up the performance.


A small example to share if you don't mind which proves we are on the same page. I am all about efficiency. Last month I had a customer with S38 3900cc Dinan 92mm stroke crank. Engine has fresh rebuild 280 Schrick intake cam, 264 Exhuast cam, custom 10.5CR, de-cated exhaust system, its has been tuned via Emulator to use the OEM Motronic 1.3 system. My customer wanted more power and I said lets put it on the dyno and see what it makes and will start from there. The engine produced 292rwhp https://www.youtube.com/watch?v=NAFYo0YzkCo This is the the 3rd 3.9 car which makes in the range of 290rwhp I have tested on the same dyno.

This is the efficiency I am speaking of. Here is my S38 on the same dyno with M62 cats, even the ambient temp was very similar (On my car I have 315/35/17 rear tires so more drag vs 235 45 17) bone stock 3535cc https://www.youtube.com/watch?v=e7nLYTqrtg8 with a custom profile cams and everything else is stock, head, valves 7mm, intake, system, stacks, 10CR, etc.

Eifficenty is the key: Knowing the head flow whit factory 7mm valves, ITB flow on the stock S38. I build a custom profile intake and exhaust cam, I have done a test in my exhaust system to ensure there is not excessive back pressure which will limit my power gains. My last adjustment on the cam timing and my 3D velocity stacks I gained few more HP and little flatter torque curve towards my new rev limiter of 7750rpm. https://www.youtube.com/watch?v=y5S6tIOoNGU Also revving characteristics has been improved as well.

If we know the parts flow, making sure the exhaust system (headers) there is no excessive back pressure, knowing the camshaft profile (meaning not the advertised duration) knowing how much CR is the engine turning we can calculate approx. BMEP and get pretty close http://www.epi-eng.com/piston_engine..._yardstick.htm Blair is a great source of information I have seen long ago.


Regards,
Anri

[Anri]

Steve,


I was able to find a dyno which I have done a test on 4th and 5th gear on Dyno-Jet. The car is stock E39M5 after major service to ensure we have proper and healthy engine I have done a dynotest

US E39M5 is ratate by BMW AG crank 394hp (SAE). G420 gear box has 4th gear ratio of 1.23 and 5th is 1:1 final drive is 3.15. Rear tires are 275 35 18 at 25.6' diameter.

In the chart 5th gear run is in Green. As we can see there is no difference in HP between 4th and 5th. The 5th gear "Test" was done on the second pass so it was not the last where the engine gets heat soaked. S62 is very sensitive to heat and timing retard.

394 crank hp (SAE) with 14-14.7% drive train losses on Dyno-Jet it comes to exact ~335rwhp+/- few hp.

The Actual run test on 5th gear from the beginning to the end it took 16.84seconds. https://www.youtube.com/watch?v=7z1hdTtCLl4


Here is Luca's M3 dyno pass https://www.youtube.com/watch?v=bsfR...&t=35s. Clearly it has been done using the "Model" which you have described as hi gear and short run. The entire pass is 9 seconds. (using 2nd gear I as far as I can hear)


Hub-Dyno: Recently we tuned an S52 with cams etc on hub-dyno, it has 3.91 final drive. It showed 292rwhp and was tuned on 4th gear 1.23. After the tune was done I asked the tuner to do a run on 5th 1:1 gear. Power dropped to 275rwhp on 5th.......That is what I call a massive difference of 17rwhp just in a gear change 4th to 5th using hub Dyno. This is not possible with Dyno-Jet.

The 2nd additional chart I am attaching is from E30M3 S54 swap, 3.46 rear diff, passes are done on 4th gear 1.23, 24.7" tire diameter same tire pressure etc.. Note the pass in Green chraph is done on 5th 1:1 the rest are done on 4th 1.23. https://www.youtube.com/watch?v=aED0OnOjBMY The neglected difference between gears 4th and 5th in green is only happening with Vanos engines, on engines like ours without vanos system the graph is identical on 4th and 5th. HP stays same.



Regards,
Anri

[lucam3evo2]

Anri
I was in 4th gear
Maybe it looks like lower gear from the sound

[Anri]

I hope to find the dyno chart of the first test. It made 200 hp. After running in it made 247 hp and then 253 ..

Hi Luca,

Were you able to find the dyno from when the enigne was stock ?

If the std engine made 200hp and after all of the work you have done you made 253hp then you have gain of 53hp.

If the numbers are correct you are puling somewhere around 108-110hp per liter depending on your bore? (std. is 93.4mm so how far did you go with your new pistons). Not a bad at all, but why not more ? My personal opinion is that you are not taking full advantages from your performance package/work done.

Consult back with John who I assume helped you to build the engine and supplied the parts, head work etc. See what he says and try it.

Regards,
Anri

[lucam3evo2]

Hi Luca,

Were you able to find the dyno from when the enigne was stock ?

If the std engine made 200hp and after all of the work you have done you made 253hp then you have gain of 53hp.

If the numbers are correct you are puling somewhere around 108-110hp per liter depending on your bore? (std. is 93.4mm so how far did you go with your new pistons). Not a bad at all, but why not more ? My personal opinion is that you are not taking full advantages from your performance package/work done.

Consult back with John who I assume helped you to build the engine and supplied the parts, head work etc. See what he says and try it.

Regards,
Anri

Hi Anri,
Yes . that's what I think too. not so much for numbers (hp) at all.
and thank you because you are helping me to understand.
i wrote to John for some time but i think he is busy

when I did 200 hp we realized that the engine was out of phase. that's where I bent the valves and rebuilt the engine.
I hope to find the graph from the tuner
Luca