Lower Compression Rotors for the REnesis
12-20-2010, 11:21 AM
#26
If you are able to use W/M without it causing a net loss of power, you have already overstepped the limits of the available materials by either over-timing or under-fueling the calibration or by operating the power-adder well beyond its efficiency boundaries.
OD you are going for reliable 300 whp using 93 octane. 93 octane will easily support that goal especially with your spray as a hedge.
12-20-2010, 08:20 PM
#30
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yes but he doesnt want "more powar!" he wants a safety margin. the 93 octane plus the water injection will give him that feeling of security on the street. for the track he can switch to 100 octane so he doesnt have to worry about running out of water.
now someone want to tell OD what the downside is to switching to the lower compression rotors?
now someone want to tell OD what the downside is to switching to the lower compression rotors?
12-20-2010, 08:52 PM
#31
thats what i thought also Zoom, i had my temps well under control, water meth 50/50 (no i dont loose power per dyno up to about total of 175 cc of spray ), good ignition , lower redline, pettits conservative tune, injectors cleaned and balanced 1 yr ago and a 09 fuel pump that never has shown any starvation issues-- all on a 10K mile engine with great compression.
It blew on the way home while not under any boost. Meaning I think that the damage had been done beforehand and it just choose that moment to let go. No det was heard --nothing--just started a dead skip.
I was at MAX of 10lbs boost ever on this engine. About 600-750 of track miles. Redline at 7.5K Never over temps of 215F
So, I thought I was covered too---I wasnt. So looking for something else--hence exploring the low compression route?
OD
It blew on the way home while not under any boost. Meaning I think that the damage had been done beforehand and it just choose that moment to let go. No det was heard --nothing--just started a dead skip.
I was at MAX of 10lbs boost ever on this engine. About 600-750 of track miles. Redline at 7.5K Never over temps of 215F
So, I thought I was covered too---I wasnt. So looking for something else--hence exploring the low compression route?
OD
12-20-2010, 10:49 PM
#33
It will do a better job, it will give him a wider safety margin, it will cost less and it will remove several failure points from the system.
Talk about babying it!
I'm pretty sure your reliability issues are not going to be found by looking for a way to INCREASE the boost on lower static compression, especially if you are planning on doing it with that blower.
You'll just be putting more heat into a motor that is obviously not tuned correctly.
Last edited by MazdaManiac; 12-20-2010 at 11:37 PM.
12-20-2010, 11:00 PM
#35
We've been at the why now for a while, whatever compressor is more efficient (boost or engine), should do the majority of work. Period.
A Blower running at 60% eff, is NOT going to be more efficient at higher boost levels, than just leaving the engine alone. Never mind, the numerous drive-ability issues.
A Blower running at 60% eff, is NOT going to be more efficient at higher boost levels, than just leaving the engine alone. Never mind, the numerous drive-ability issues.
12-20-2010, 11:52 PM
#37
That said, the carbon is only an issue if you baby the motor and even then, it only affects the seal grooves - something that happens NA with the OE calibration.
There are plenty of countermeasures for that, but introducing a noninflammable material into the combustion process when there are ways to add fuel value just so you can scrub carbon is ridiculous.
12-21-2010, 12:35 AM
#38
There is a pretty good chance at this point that I have tuned and torn-down more Renesis FI applications than you have even actually seen, so it is safe to say that I am well aware of what unburned fuel does.
That said, the carbon is only an issue if you baby the motor and even then, it only affects the seal grooves - something that happens NA with the OE calibration.
There are plenty of countermeasures for that, but introducing a noninflammable material into the combustion process when there are ways to add fuel value just so you can scrub carbon is ridiculous.
That said, the carbon is only an issue if you baby the motor and even then, it only affects the seal grooves - something that happens NA with the OE calibration.
There are plenty of countermeasures for that, but introducing a noninflammable material into the combustion process when there are ways to add fuel value just so you can scrub carbon is ridiculous.
Inspired ... don't be foolish enough to let that get to you, there are other people who are listening to you but just don't have the guts to post
12-21-2010, 12:44 AM
#39
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The ego's around here are soo big its sad so I could care less to post anything around here anymore. You guys are repeating history. Keep up the good work.for all we know you could be Amemiya-san. But we dont know, and you have little credibility here compared to those you discredit the ideas and work of
most ppl here arent gonna come out and say you're wrong/right. they're gonna listen to the few that have earned credibility. you dont seem to get that principle
12-21-2010, 12:58 AM
#40
I've spent a considerable time demonstrating my work. I've published countless threads and articles elsewhere with results gleaned from actual tuning, experimentation and building. It is all out there.
Certainly, if you have any cognitive capacity at all, you must realize the irony in YOU stating that the egos around here are too big.
Actually, we are moving forward without being trapped in old ideas which is apparently your shortcoming in this discussion.
12-21-2010, 01:24 AM
#42
However, adding a gallon of xylene to 13 gallons of regular 91 RON/MON will raise the octane of the whole tank to 93.
Since the stuff is typically $14 USD per gallon, that probably isn't effective for "every tank".
12-21-2010, 04:17 AM
#43
rev it up
Ok, so if you go to the track where the car is performing at its maximum potential then this can be a deterrent?
If so do you have to alter the tune each time you go to the track to compensate or will a safe tune be able to cope for all occasions.
skc
If so do you have to alter the tune each time you go to the track to compensate or will a safe tune be able to cope for all occasions.
skc
12-21-2010, 04:26 AM
#44
If you are using this for power, you alter the tune, if you are using it for insurance, you leave the tune alone.
Higher octane will not affect the power output of the engine. More timing, and less fuel WILL, but at the cost of safety.
12-21-2010, 07:12 AM
#46
You americans don't even know what Pizza tastes like so...
Anyway bringing this IT, i think that lowering the compression ratio is useless for most and marginally appreciable for some.
Static compression is just part of the puzzle and should depend on several factors like turbo choice (hence expected flow) etc.
In Denny's case i think that the supercharger is already at its efficiency limit so that doesn't look like a great solution.
Getting the tune right in the first place (no pettit standard tune bs) and addressing the weakpoints may be the best route to follow. Limiting the redline to 7500rpms is pointless, 8300 i would understand but 7500...
Anyway bringing this IT, i think that lowering the compression ratio is useless for most and marginally appreciable for some.
Static compression is just part of the puzzle and should depend on several factors like turbo choice (hence expected flow) etc.
In Denny's case i think that the supercharger is already at its efficiency limit so that doesn't look like a great solution.
Getting the tune right in the first place (no pettit standard tune bs) and addressing the weakpoints may be the best route to follow. Limiting the redline to 7500rpms is pointless, 8300 i would understand but 7500...
12-21-2010, 10:11 AM
#48
Ray---thanks for a good read. Some really good info there. Especialy addressing temps and the ignition system. Others should read that.
My tune was not a standard Pettit flash. Actually there is no standard Pettit flash, only the base flash that is modified to the indv car.
Mine was street tuned at Pettit. As little as i know about how to use the tuning equipment---i do know that I dont have drips in the a/f's when the intake valves open, my a/f's are on target with just about everyone else's I have seen, my timing is right were others seems to have. Tune seems ok to me.
My intake temps, measured at the junction of the lim and uim NEVER got over 140F--even on track. I repeat I DO NOT loose power with my w/m spray.
But, still, Steve Kan comes to Atlanta from time to time and I am on the list for him to look at it all--since I now have a Cobb unit. It will be a little while before he gets in town.
My engine weakness may have been my ignition system. Although I never had any misfires that I am aware off, my plugs always looked really good etc etc. Since I now have the Cobb my Ls2 coils will be reinstalled with the proper dwell.
You know---I would not be surprised if I find out that I blew a corner seal instead of an apex? IDK but the engine just cranks to easy and has too much power and airflow in comparison to my other blown engines.
I do know I am dropping to a 7 psi boost pulley size for now.
And MM I think you may have a point. I may be hanging around the TQ peak range too much.
OFF TOPIC question---how are others using the TB coolant line? Capping it or just bypassing the TB?
My tune was not a standard Pettit flash. Actually there is no standard Pettit flash, only the base flash that is modified to the indv car.
Mine was street tuned at Pettit. As little as i know about how to use the tuning equipment---i do know that I dont have drips in the a/f's when the intake valves open, my a/f's are on target with just about everyone else's I have seen, my timing is right were others seems to have. Tune seems ok to me.
My intake temps, measured at the junction of the lim and uim NEVER got over 140F--even on track. I repeat I DO NOT loose power with my w/m spray.
But, still, Steve Kan comes to Atlanta from time to time and I am on the list for him to look at it all--since I now have a Cobb unit. It will be a little while before he gets in town.
My engine weakness may have been my ignition system. Although I never had any misfires that I am aware off, my plugs always looked really good etc etc. Since I now have the Cobb my Ls2 coils will be reinstalled with the proper dwell.
You know---I would not be surprised if I find out that I blew a corner seal instead of an apex? IDK but the engine just cranks to easy and has too much power and airflow in comparison to my other blown engines.
I do know I am dropping to a 7 psi boost pulley size for now.
And MM I think you may have a point. I may be hanging around the TQ peak range too much.
OFF TOPIC question---how are others using the TB coolant line? Capping it or just bypassing the TB?
Last edited by olddragger; 12-21-2010 at 11:04 AM.
12-21-2010, 06:24 PM
#49
So far the only thing we have seen that are thought to have caused cracked irons, to my knowledge anyway, are poor castings from the factory.
Julio Don advised me that AITs become a concern above 150F.
99% of "blown" Renesis engines, boosted or not, break the apex seal in the fashion you have described.
We are now starting to see corner seals split in half, as well, and they have arisen in nitroused and N/A cars. Maybe some boosted apps, too, but I am not sure........
Julio Don advised me that AITs become a concern above 150F.
99% of "blown" Renesis engines, boosted or not, break the apex seal in the fashion you have described.
We are now starting to see corner seals split in half, as well, and they have arisen in nitroused and N/A cars. Maybe some boosted apps, too, but I am not sure........
12-21-2010, 06:33 PM
#50
This is a good read OD. It does discuss piston engines. But it is loaded with good info.
compression_ratio_tech
compression_ratio_tech
Hi. My name is Ray now.
