Anyone been lifting heads?
On The Tree
Joined: Nov 2001
Posts: 1,100
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From: Charlestown, Indiana
In my opinion, 12.5:1 on the dyno is way lean. That would be about 13.5:1 or leaner on the street.
We tune for 11.0-11.5:1 on the dyno, with 11.8:1 being the leanest we would ever let leave the shop. And that would only be if the person planned on running race gas.
My guess would be that the 104 octane fuel you are running is the only thing saving you right now.
Just my opinion though.
We tune for 11.0-11.5:1 on the dyno, with 11.8:1 being the leanest we would ever let leave the shop. And that would only be if the person planned on running race gas.
My guess would be that the 104 octane fuel you are running is the only thing saving you right now.
Just my opinion though.
Originally Posted by Rob Raymer
In my opinion, 12.5:1 on the dyno is way lean. That would be about 13.5:1 or leaner on the street.
We tune for 11.0-11.5:1 on the dyno, with 11.8:1 being the leanest we would ever let leave the shop. And that would only be if the person planned on running race gas.
My guess would be that the 104 octane fuel you are running is the only thing saving you right now.
Just my opinion though.
We tune for 11.0-11.5:1 on the dyno, with 11.8:1 being the leanest we would ever let leave the shop. And that would only be if the person planned on running race gas.
My guess would be that the 104 octane fuel you are running is the only thing saving you right now.
Just my opinion though.
9 Second Club
Joined: Jul 2003
Posts: 1,195
Likes: 0
I agree with Rob. I do think you are on the far edge. If you do the o-ringing of the heads the best way is to have a receiver groove cut into the block. I don't think you could blow a gsk that way. It would be really hard IMO.
The replies are great and interesting. What I am seeing is not many have had head lifting issues, and when they did it was likely the tune as it pertains to the way it was...well...driven.
I'll add a follow up question...if thew heads are ringed, and the block isnt...is that really gaining much? This should be addressed and expl;ained. Brian? You out there? Rob, you have experience with O-ringed Judson TEAs if I remember right... chime in...
I'll add a follow up question...if thew heads are ringed, and the block isnt...is that really gaining much? This should be addressed and expl;ained. Brian? You out there? Rob, you have experience with O-ringed Judson TEAs if I remember right... chime in...
Originally Posted by JamMasterJ
The replies are great and interesting. What I am seeing is not many have had head lifting issues, and when they did it was likely the tune as it pertains to the way it was...well...driven.
I'll add a follow up question...if thew heads are ringed, and the block isnt...is that really gaining much? This should be addressed and expl;ained. Brian? You out there? Rob, you have experience with O-ringed Judson TEAs if I remember right... chime in...
I'll add a follow up question...if thew heads are ringed, and the block isnt...is that really gaining much? This should be addressed and expl;ained. Brian? You out there? Rob, you have experience with O-ringed Judson TEAs if I remember right... chime in...
Kyle
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Registered User
Joined: Jun 2002
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From: Forced Induction Heaven
Originally Posted by Rob Raymer
In my opinion, 12.5:1 on the dyno is way lean. That would be about 13.5:1 or leaner on the street.
We tune for 11.0-11.5:1 on the dyno, with 11.8:1 being the leanest we would ever let leave the shop. And that would only be if the person planned on running race gas.
My guess would be that the 104 octane fuel you are running is the only thing saving you right now.
Just my opinion though.
We tune for 11.0-11.5:1 on the dyno, with 11.8:1 being the leanest we would ever let leave the shop. And that would only be if the person planned on running race gas.
My guess would be that the 104 octane fuel you are running is the only thing saving you right now.
Just my opinion though.
Yes your opinion definetly counts.
What I was told and you guys correct me if its wrong...is that if the fuel tables are zero'd out..then there is not much of a difference at all on the dyno vs. the street. Rob or PSJ are you buying that????? When you guys tune are you getting your Fuel Trims zero'd out???
Thanks
All the folks I have talked to who run 700-1000 hp setups suggest the numbers that Rob posted. You will run a full point more lean on the street is what everybody said. I'm including tuners of low 9 second Supras and 8 and 9 second Mustangs.
Not when you use a real dyno 
12:1 on the dyno, and 12:1 on the street for me. Same WB in the car for street and dyno.
I've been using MLS gaskets and studs with great results. Not lifting, no cooling system pressure.
12:1 on the dyno, and 12:1 on the street for me. Same WB in the car for street and dyno.
I've been using MLS gaskets and studs with great results. Not lifting, no cooling system pressure.
Shinobi, it depends which dyno you used. The table being zero'd out doesn't change the fact that a DynoJet dyno does not load the engine like a wot street run. If you used a Mustang dyno you're ok but could use a little more fuel. If it was a Dynojet, then you're way too lean on the street.
Registered User
Joined: Jun 2002
Posts: 453
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From: Forced Induction Heaven
Yes it was a dyno jet 248. We are going to run EFI Live or a Tech II and take the car out for a spin. We should be able to pick up any detonation. I was told that if the dyno was right and the tables were Zero'd out that it would not make a difference. Argumentively though I have seen dyno graphs of LPE cars that show them at 13.1 on a 248 Dynojet.
I run 91 octane and 11lbs of boost on the street. The AFR was supposed to be 10.5:1 but I think I hear detonation. I have been told that the internal wastegates are very loud and make a quick series of tapping sounds..I want to just verify that it is not detonation.
Thanks
I run 91 octane and 11lbs of boost on the street. The AFR was supposed to be 10.5:1 but I think I hear detonation. I have been told that the internal wastegates are very loud and make a quick series of tapping sounds..I want to just verify that it is not detonation.
Thanks
For the record if you have audible detonation in a FI car you are on the slippery slope.
Someone might pull their car on a Dynojet 248 at 12.5-13.1 PSI but the racers will back the tune off to make it safe.
I personally talked to like 10 different tuners on this issue and they were all the same, 11-1 to 11.5:1 on the dyno at WOT.
Someone might pull their car on a Dynojet 248 at 12.5-13.1 PSI but the racers will back the tune off to make it safe.
I personally talked to like 10 different tuners on this issue and they were all the same, 11-1 to 11.5:1 on the dyno at WOT.
Registered User
Joined: Jun 2002
Posts: 453
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From: Forced Induction Heaven
Originally Posted by Pro Stock John
For the record if you have audible detonation in a FI car you are on the slippery slope.
Someone might pull their car on a Dynojet 248 at 12.5-13.1 PSI but the racers will back the tune off to make it safe.
I personally talked to like 10 different tuners on this issue and they were all the same, 11-1 to 11.5:1 on the dyno at WOT.
Someone might pull their car on a Dynojet 248 at 12.5-13.1 PSI but the racers will back the tune off to make it safe.
I personally talked to like 10 different tuners on this issue and they were all the same, 11-1 to 11.5:1 on the dyno at WOT.
So whats a RACER????
Seriously I appreciate the information. This is why I will go out on the street and verify if I am getting detonation with a Tech II or EFIv6. If I am not I know everything is cool...if I am than I will find a way to fix it. I have to put in a new clutch anyway...my clutch won't even hold the peak power my setup made on the dyno let alone with a load on it....wished they would have had a loader on the Dynojet like they have with a Mustang Dyno.
I just double checked my Air/Fuel for both boost runs.
The AFR on the 11-12.5lbs of boost run, using 91 Octane was 11.2.
The AFR on the 14-16.5lbs of boost run (boost controller on), using Sunoco 104 Octane was 12.7.
Last edited by Shinobi'sZ; Jan 13, 2004 at 04:46 PM.
Looks like you're safe at 11psi....not safe at 14psi.
FWIW I've seen 2 LPE TT Dynojet dynographs....both where 11.4 to 11.6 AF.
Somethings wrong with the LPE 13:1 TT Dynojet.....could it have been NA?
FWIW I've seen 2 LPE TT Dynojet dynographs....both where 11.4 to 11.6 AF.
Somethings wrong with the LPE 13:1 TT Dynojet.....could it have been NA?
Not to start a fire, but I saw/have an A/F from one of the "Major" NJ Tuners that gets into the 13's at upper RPM/s at WOT. Same car saw 3k+miles and over 50 1320's this season with that tune. I would not do it myself, just stating one mans "situation".
If I remember right, Rob used stock GM gaskets (graphite?) on his "old, now sold" car.
Where is that car anyway....did a forum member buy it?
Y2K, you always give me hope...MLS..no orings...love it.
I guess I'll go that route and w/ some of those special $375 ARP head studs from Dave White.... at least thats todays vision...I dont see too clearly though....
If I remember right, Rob used stock GM gaskets (graphite?) on his "old, now sold" car.
Where is that car anyway....did a forum member buy it?
Y2K, you always give me hope...MLS..no orings...love it.
I guess I'll go that route and w/ some of those special $375 ARP head studs from Dave White.... at least thats todays vision...I dont see too clearly though....
TECH Senior Member
Joined: Nov 2001
Posts: 10,341
Likes: 1
Richen it up to 11-11.5:1 on a dynojet especially if you are turbo.
Blower cars are not load dependant so you can go a little leaner. I would still never go above 12.2:1 on a dynojet though with a supercharger.
You want a little cushion regardless.
Chris
Blower cars are not load dependant so you can go a little leaner. I would still never go above 12.2:1 on a dynojet though with a supercharger.
You want a little cushion regardless.
Chris
TECH Resident
Joined: Jan 2002
Posts: 956
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From: Phoenix, AZ
#'s in my sig were exactly what Chris and John say, 11-11.5:1 on dynojet. Seems to be giving me decent enuff power! And this Saturday 918's are replacing the weak stockers, look for that HP to jump up close to 630 
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