GoRacer

iTrader: (2)

I went to a new local Japaese shop to get my oil leak fixed and they offered a tune. Not knowing if I could do the Steve Kan group tune and afraid of XS-Engineering's prices I said yes. I didn't get a chance to clean my plugs, so they changed my HKS race plugs which looked bad for some OEM 9P's. They also threw in Mobil-1 15-50. Well it took a while to resolve my boost control problem but they found the correct wastegate plug. I had the do a base run for comparison and to see how much power I lost with my Moroso Spiralflow in the mid pipe and it was 255whp on a Mustang. I was told it reads 50hp low but it would make more sense if it was a percentage. Also, since it's a loaded dyno then shouldn't it be the correct number and dynojet numbers be lowered? Anyhow, he did a compression check and got (forgot paper) approximately 7's on both rotors but one face was 6.7k. Rebuilt 5000 miles ago my engine was approximately all 8's. He did several runs before the boost control and wastegate issue was resolved. Then he turned up to .9bar and I got 259whp. So if +50 is correct then 309whp. Which means I lost 12hp from my Moroso Spiralflow since my previous tune was 321whp. Ok, that's fine but I only gained ...well actually I don't think I gained anything adding 3lbs of boost. Wait I gained like 4whp or something like that with +3lbs. This really doesn't make any sense to me. I was expecting 400whp @ 15lbs. He said he was afraid to go to 1bar becuase of my compression. I go back tomorrow for him to smooth out my map. Lower compression should handle more boost so i'm confused. I was going to ask him to finish the tune at 1.02bar.

If this is in the wrong section, sorry.

Sr20fd3st

what do you mean low compression? if your motor has low compression..well you're gonna lose power obviously...but if your talking about rotors with a lower compression then yes the motor would technically handle more boost..but i didnt know you could get different compression rotors...

compression ratio and compression in psi arent the same thing man...if you got low psi numbers you need a new motor..if it's low enough that is

rynberg

^^^ what he said

That aside, how much experience does this new shop have tuning single turbo FDs? (or rotaries at all for that matter)

And I wouldn't just add 50 rwhp to your numbers. I made 23X at 10 psi on a Mustang Dyno with just a few bolt-ons and the stock ecu. IIRC, guys running 13-14 psi on Pettit/M2 ecus and with all bolt-ons on stock twins were hitting around 270.

GoRacer

iTrader: (2)

Sorry I keep thinking they are. My engine was rebuilt 5k miles ago and tuned by Steve Kan after break in. It was only tuned for 10lbs. I tried to retune for 15lbs at Neptunespeed in Huntington Beach. Apparently the shop has done well with 2nd gen's. I am one of the first with a 3rd gen there. I am now really nervous to let them try again.

Those are the compression numbers he showed me on a Mazda compression tester. One of the three numbers on the front rotor was 0.67k. I can only assume that converts to 6.7 for one of the faces. All the rest of the numbers were around 0.70 and 0.71k. I was told the 6.7 was a bad side seal most likely installed wrong.

The engine was compression tested at the shop when installed and it avg'd 8.0. I know good compression is 9.0 and that's why I mix up 9:1. I have premixed with every tank and broke the engine in before tuning. I don't understand how I could possibly get those numbers. Should he have tested with the engine cold?

How do you convert Mustang Dyno numbers?

Sr20fd3st

No, test for compression with motor warmed up. you want a good oil seal and you want the metals to expand so the clearances are as tight as possible to give you accurate numbers.

If your getting lower compression than you should and you broke it in like you should i would go to the shop that built it. who rebuilt your motor? u get a warranty with it? if they did install a side sea wrong and they tear it apart and find that out, and its under warranty, they ought to rebuild it again for you for free... loss in compression is gonna rob you of power, expecially when boost kicks in.

maybe the guy tuning it now is afriad that with the less compression your having that more boost is just gotta be wasted.

And I'm sure a Steven Kan tune at 10psi would produce more power than some random shops tune at 15 psi lol

I guess let the dude do the best he can

Mr rx-7 tt

iTrader: (5)

Make sure when they did compression test that the butterflies were open all the way (Throttle opened all the way, foot on the floor) and the engine was warm and the battery had a full charge. Try that and see if the numbers come up. Where are you at in California? Near LA? If so call Rotary Power and talk to Jeff MCaul.

http://www.rotarypowerusa.com/contact.htm

As far as the side seal improperly installed, I doubt it. It sounds like it may be sticking or cut wrong. If the car isn't a daily driver pour some ATF into the engine and let it sit for a couple days. It may clear up your problem.

pluto

If he was using a Mazda compression tester, what RPM was this test at? If it was anything less than 225rpm, your compression is fine. however, that one low number does concern me a little. This could be a couple of things. Either you have a dent on the face of the rotor (due to detonation) or your side seal is too sloppy (leaky compressioin). Do you get alot of oil blow-by on your engine? Both of which is not that big of a deal but it will not get any better. Also, get rid of the Mobil 15W-50 oil and put some 20W-50 in it. I personally would not use Mobil-1 on any of my vehicles.

as for the % for a mustang dyno vs. dynojet. I have heard anywhere from 20-25% difference. Ask Lupe and see if he remembered on the % since we used the mustang dyno on the first tuning session in St. Louis.

Either way, 4rwhp gain with 3psi increase doesn't sound right to me. What was the load factor he was using?

Jason

iTrader: (5)

Mustang dyno is usually 8-10% lower than a dynojet. Just for reference.

Jason

GoRacer

iTrader: (2)

I'm not shure what RPM he was cranking the motor with the tester in one spark plug hole, so I have no idea what rpm it could have been. I didn't know to ask.

He told me I had a bad side seal to. But besides that, my numbers when the engine was dropped in were 7.9, 8's & 8.1. I'm assuming the 7.9 is the current 6.7.

I haven't noticed any oil in the pipes. I do however have an oil leak from when the engine was installed. I was told it was fixed but it wasn't. I can loose up 1/3 or maybe 1/2 quart of oil overnight. Neptunespeed says it's the oil pan.

I spoke with Kyle at Mazdatrix and he thinks I may have (a) warped apex seal(s). Possibly from the fuel pressure regulator lines being crossed when installed. He said they don't use a gasket on the pan, so the probaility of the leak being the pan is low.

I can't get an appointment with Mazdatrix, their booked up for weeks. I don't want Neptunespped to remount the oil pan because if that is the leak then it would be a warranty issue and I won't get reimbursed for it. If it's not the leak?

I went to XS Engineering but they are booked untill the middle of April. They have done alot of high powered single turbo FD's. So i'm pretty much stuck, scared to drive the car and down for the season with only one race.

I went back to Neptunespeed they said they would clean up the map but all he did was change boost to .9 and duty to 40 on one of two of the second boost settings. (power FC has 4 settings turbo 1 has 2 and turbo 2 has 2) He changed the very bottom/last one.

I will put castrol 20-50 in it. Thanks for the help Steve!

GregFD3S

6.7 on only 1 face? if you had "warped" or even if the apex seals were installed wrong, you would be showing low compression on 2 faces, not 1.

if it is showing lower compression on 1 face, then it was probably a side seal that was installed improperly.

GregFD3S

another thing... what were your break-in procedures?

RotaryEvolution

iTrader: (30)

sounds like a crap tune and an improper compression test to me.

yes, having fairly low compression will affect the overall output of the engine when the PSI is cranked up since a portion of that pressure is lost bypassing the seals but it peaking out that early doesn't make much sense unless the turbo is just crapping out at those boost levels.

Sr20fd3st

did it run fine on the previous steve kan tune?

GoRacer

iTrader: (2)

Front: Rear:
0.75k 0.75k
0.67k 0.73k
0.79k 0.71k

Break in was done with variable speeds and lengths. It was never held constant as well as exiting/entering every on/offramp. Stoppping and shutting engine off with a coold down periods in between long runs (gas, food, soda, auto store, etc) as well with the hood open. Water checked, oil checked and topped off with 10-30 dyno changed every week or appriximately every 500 then 1k miles. I beleive the first oil change was after 250miles. Castrol GTX, Purolator Pure1 and Red Line 2-stroke racing for premix.

GregFD3S

what about RPM range and boost during your break-in period?

Sr20fd3st

yea u gotta make sure to keep below like 4500 and no boost at all ever...

GoRacer

iTrader: (2)

No boost during break in. I might have hit 1 or 2 lbs by mistake but since my autometer reads 1.5-2lbs too high, it's safe to say no boost. RPM's were under what I was told. I know the first 500 miles were 3k and lower, then 500rpm increments every 500 miles.

RotaryEvolution

iTrader: (30)

doesn't sound like a faulty break in, sounds like a faulty rebuild with a worn side seal or sticking corner seal.

try running a carb treatment on the engine and see if it brings the numbers up. if the engine was running excessively rich for an extended break in then sticking seals shouldn't be ruled out and can possibly be resolved.

GoRacer

iTrader: (2)

Just noticed on invoice/receipt it states compression was done at 250rpm's. I can't remember how long the car had been cooling off before the test though.

pluto

Those numbers seemed low at the rpm but okay for 3mm seals. are you running 2mm or 3mm seals?

GoRacer

iTrader: (2)

Mazda 2-peice 2mm apex seals and springs. I had RA apex seals but they will only install Mazda OEM. OEM side seals with the rubber plugs. I wanted solid but was told it wasn't a good idea. I was afraid of something like this since I had three flattened ones on the front rotor with the last engine and I thought solid would prevent it.

pluto

those numbers are low for the given rpm and seal used....

GoRacer

iTrader: (2)

^ so does that mean I should not risk a retune?

Should I now be looking at a rebuild before the apex seals break?

I don't understand Neptunespeed then. They wouldn't finish the tune from 13 to 15lbs because of low compression, but he said it was ok to turn the boost up to 1bar with the 13lb tune.

Just out of curiosity, have you done and FD engine with RX8 rotors?

GoRacer

iTrader: (2)

What carb treatment stuff would that be ...Seam Foam?

rynberg

BS.....