Stock motor vs iat vs #boost
#16
I will give you one part. Make SURE you adjust the Minimum advance tables. You can fill the other tables with what ever you want if the Min table is not adjusted you will get what ever is in them. Cost me a head gasket to find those tables.
#17
I would say that most people who have tried to boost a stock engine have failed, including myself. I ran the d1sc with twin highflows at 8 psi, ran for a few months real hard, then the rings got tired and lost compression in a coupple of cylinders. My advise is do it right and buid the damn motor...because you will be doing it soon if you arent carefull.
#19
cause4panic:
My boost is quite mild. I'm planning to limit my advance at high rpm & map to the mid or low 20s. I think people are reluctant to give specific answers because the serious players have lots of dyno time and money invested in getting it right. ISTR reading some suggestions of pulling at least 2 degrees of advance for every pound of boost above an NA motor at the upper end.
My boost is quite mild. I'm planning to limit my advance at high rpm & map to the mid or low 20s. I think people are reluctant to give specific answers because the serious players have lots of dyno time and money invested in getting it right. ISTR reading some suggestions of pulling at least 2 degrees of advance for every pound of boost above an NA motor at the upper end.
Unless you have lots of experience with tuning FI LT1's, I would strongly reccomend leaving the tuning to the experts like Bryan Herter at PCM's for less. Then you can leave all the timing and fine adjustments you'll need to make up to the pro, and you'll know its a good tune.
#20
Really good replies guys, much appreciated. one flyn z thanks for the advice on the min tables. call 911 thanks for the advice aswell.
so im gonna try to get my a/f r's in the low 11's and retard the timing to all hell. Im just worried that pulling the timing down to 16 deg or so will raise my egts up very high.
How can i tell what the engine "wants" besides experimenting? or looking at other peoples tunes.
So i believe end of this week (pay week) i will be ordering the mpt70 and that big ace intercooler. Sill need to get a new spring for the wastegate since its a 9 lb spring currently. Can anyone reccomend a good meth/h20 kit? Im gonna need to drench the pistons in water/meth to keep these things alive.
BTW i dont know how you guys drive your cars but i can tell you that i drive like a fricking grandmother unless the pedel is to the floor(maybe a handfull of times a weekend). There are weeks were i dont even floor the car!!!! Being in queens with anything that makes noise or even looks like it goes fast gets WAAAAYY to much attention from the cops.
again guys thanks for the help. Once i start getting parts in i will be doing a build up thread.
so im gonna try to get my a/f r's in the low 11's and retard the timing to all hell. Im just worried that pulling the timing down to 16 deg or so will raise my egts up very high.
How can i tell what the engine "wants" besides experimenting? or looking at other peoples tunes.
So i believe end of this week (pay week) i will be ordering the mpt70 and that big ace intercooler. Sill need to get a new spring for the wastegate since its a 9 lb spring currently. Can anyone reccomend a good meth/h20 kit? Im gonna need to drench the pistons in water/meth to keep these things alive.
BTW i dont know how you guys drive your cars but i can tell you that i drive like a fricking grandmother unless the pedel is to the floor(maybe a handfull of times a weekend). There are weeks were i dont even floor the car!!!! Being in queens with anything that makes noise or even looks like it goes fast gets WAAAAYY to much attention from the cops.
again guys thanks for the help. Once i start getting parts in i will be doing a build up thread.
#21
Like I said before, unless you have lots of experience tuning FI LT1's, I would leave the tuning up to someone who knows what they are doing there, as it is fairly difficult to get a sound tune on a FI LT1, given the fact the MAF usually maxes out after a while, and we only have 1 bar MAP sensors.
If you get a FAST XFI setup with maybe a wideband 02 sensor, and have lots of good experience using it, a good tune can be performed yourself, but I can't stress enough that you should spend the $ and get a good tuner to tune the car.
BTW, I am running a Snow Performance meth injection kit with great success. Most people go with either Alky Control's kit or Snow Performance (both are great). There are other kits available like Devils own, and AIS.
If you get a FAST XFI setup with maybe a wideband 02 sensor, and have lots of good experience using it, a good tune can be performed yourself, but I can't stress enough that you should spend the $ and get a good tuner to tune the car.
BTW, I am running a Snow Performance meth injection kit with great success. Most people go with either Alky Control's kit or Snow Performance (both are great). There are other kits available like Devils own, and AIS.
#22
Thanks for the suggestion on the meth/h20 thing. That’s another question in my mind. Do I want to run straight meth or a 50/50 water meth mix? I’m pretty sure straight meth would make more power, but in my mind a 50/50 mix would produce more of a cooling effect (save the pistons) by introducing an inert fluid like water. Slowing the flame propagation also effectively reduces the overall timing.
I have a wideband and tuner cat, I don’t want to sound or act stubborn but the thing I enjoy most about modifying anything is the satisfaction of doing it yourself. Likewise i am fairly familiar with the software and capable of logging the wideband via a/c input and plotting a/f vs rpm in excel etc etc.... If I was doing this for the final outcome I would just buy a vette and call it a day although I do appreciate you warning me about the importance of a good tune. The car will be tuned in speed density with a two bar map sensor and all changes will be done in very small increments. We all have to get our start somewhere and if this costs me a stock motor thats gonna get rebuilt anyway so be it.
But i REALLY REALLY appreciate all the help, if anyone has any suggestions i am all ears.
I have a wideband and tuner cat, I don’t want to sound or act stubborn but the thing I enjoy most about modifying anything is the satisfaction of doing it yourself. Likewise i am fairly familiar with the software and capable of logging the wideband via a/c input and plotting a/f vs rpm in excel etc etc.... If I was doing this for the final outcome I would just buy a vette and call it a day although I do appreciate you warning me about the importance of a good tune. The car will be tuned in speed density with a two bar map sensor and all changes will be done in very small increments. We all have to get our start somewhere and if this costs me a stock motor thats gonna get rebuilt anyway so be it.
But i REALLY REALLY appreciate all the help, if anyone has any suggestions i am all ears.
#23
Thanks for the suggestion on the meth/h20 thing. That’s another question in my mind. Do I want to run straight meth or a 50/50 water meth mix? I’m pretty sure straight meth would make more power, but in my mind a 50/50 mix would produce more of a cooling effect (save the pistons) by introducing an inert fluid like water. Slowing the flame propagation also effectively reduces the overall timing.
I have a wideband and tuner cat, I don’t want to sound or act stubborn but the thing I enjoy most about modifying anything is the satisfaction of doing it yourself. Likewise i am fairly familiar with the software and capable of logging the wideband via a/c input and plotting a/f vs rpm in excel etc etc.... If I was doing this for the final outcome I would just buy a vette and call it a day although I do appreciate you warning me about the importance of a good tune. The car will be tuned in speed density with a two bar map sensor and all changes will be done in very small increments. We all have to get our start somewhere and if this costs me a stock motor thats gonna get rebuilt anyway so be it.
But i REALLY REALLY appreciate all the help, if anyone has any suggestions i am all ears.
I have a wideband and tuner cat, I don’t want to sound or act stubborn but the thing I enjoy most about modifying anything is the satisfaction of doing it yourself. Likewise i am fairly familiar with the software and capable of logging the wideband via a/c input and plotting a/f vs rpm in excel etc etc.... If I was doing this for the final outcome I would just buy a vette and call it a day although I do appreciate you warning me about the importance of a good tune. The car will be tuned in speed density with a two bar map sensor and all changes will be done in very small increments. We all have to get our start somewhere and if this costs me a stock motor thats gonna get rebuilt anyway so be it.
But i REALLY REALLY appreciate all the help, if anyone has any suggestions i am all ears.
Water/methanol mix vs straight methanol is really up to you. People will argue which is better mix wise, but both have been used successfully, and honestly niether will yeild you more noticable power over the other. I am running a 50/50 water meth mix, but know several others running straight meth with good results as well. The deciding factor for me was that having a water/meth mix was cheeper than running all meth, and running 100% methanol is much harder on your system and will corrode more (and possibly take out the pump earlier).
As for the tuning, at least you understand what the risks are. You can have a fully bullet proof built motor setup to withstand tons of boost and power, but if the tune is not done properly, it can go "BOOM" just as soon as a stock motor with mild boost with a bad tune. Tuning is everything. Hopefully you get to learn a bit before you be in need of a new engine.
Last edited by CALL911; 04-09-2008 at 02:38 PM.
#24
Ok so just as a recap to this point
autolite 103's gapped at 0.035"
keep the boost low
2 bar sd tune
50/50 meth/h20
big intercooler
low 11:1 a/f ratio
But im still unsure on the precautions on timing. Should the engine never see more then 16deg advance? Should the timing peak at peak tq then start retarding towards redline?
please enligten me guys or send me a tune to look at
cause4panic@gmail.com
thank you all
autolite 103's gapped at 0.035"
keep the boost low
2 bar sd tune
50/50 meth/h20
big intercooler
low 11:1 a/f ratio
But im still unsure on the precautions on timing. Should the engine never see more then 16deg advance? Should the timing peak at peak tq then start retarding towards redline?
please enligten me guys or send me a tune to look at
cause4panic@gmail.com
thank you all
#25
Ok so just as a recap to this point
autolite 103's gapped at 0.035"
keep the boost low
2 bar sd tune
50/50 meth/h20
big intercooler
low 11:1 a/f ratio
But im still unsure on the precautions on timing. Should the engine never see more then 16deg advance? Should the timing peak at peak tq then start retarding towards redline?
please enligten me guys or send me a tune to look at
cause4panic@gmail.com
thank you all
autolite 103's gapped at 0.035"
keep the boost low
2 bar sd tune
50/50 meth/h20
big intercooler
low 11:1 a/f ratio
But im still unsure on the precautions on timing. Should the engine never see more then 16deg advance? Should the timing peak at peak tq then start retarding towards redline?
please enligten me guys or send me a tune to look at
cause4panic@gmail.com
thank you all
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