I know this as been talk about but can't seem to find it.
what is the max HP or rwhp on lt4 without a cam swap on fuel without ethanol?
I know this as been talk about but can't seem to find it.
what is the max HP or rwhp on lt4 without a cam swap on fuel without ethanol?
stock blower or any blower? you can make whatever you want at the end of the day......
Higgs thanks for the reply. any blower. wondering what is the stock LT4 fuel system able to support without a cam swap or fuel mods on pump fuel without ethanol.
I only have experience with a 32% cam lobe, have a buddy who's looking to max his stock setup with a whipple without a cam change
They make more then 500rwhp stock
the stock fuel system is good to about 700-725rwhp on E10 fuel.Originally Posted by obd2
I haven't really seen any shortblock issues with the LT4.
the LT1 fuel system is good to about 625rwhp on E10.
the stock LT1 pistons are breaking around 600 though.
what injector DC do you log on a 56lb/hr injector at 700rwhp
hmm thanks for sharing. I am finding it hard the believe whipple's claim with 14800 rpm (with 8" stock lower and 3.5 upper) 13.5 boost. Their baseline (LT4) was 540 rwhp to 640 rwhp. This was done on a completely stock ctsv without any other modifications. My past experience their tunes suck, so this claim seems far stretch let alone with 13.5 boost. Has anyone care to share their experience, or am I just too sceptical/Leary. We are preceding with install in a few weeks holding off on header install to verify rwhp. however I do believe they have the best gen5 blower
Last edited by obd2; 03-15-2018 at 04:49 PM.
these are DI system I think you are referring to port I. ;o)
600hp ?pistons breaking? sad to hear. are the ring lands close to the top like LS7? was planning on adding a lt4 blower to an lt1 cammed Camaro. what your telling me is scary. is it possible tuning was the issue?
quite a few threads like this one on CF:
https://www.corvetteforum.com/forums...n-failure.html
direct injection cars go by pulse width
we're a bit behind the times here in Aus. Looks like I've got some serious reading to do
Thanks.looking at those pic does not seem to be tune or knock related. From what I gather the Lt1 ring lands are just to weak for the extra heat/pressure. I expected them to break at the upper crown like boosted ls7 and not the lower half. cheers
I've seen the guy from Procharger post that he's seen top ring gaps as tight as .009" on a stock LT1. That is probably a big contributor to the breakages that are happening.
Depends on how safe you want the A/F ratio but 12.8 @625rwhp on race fuel will start taxing the HPFP.
I have the most success with .84/.85
are these numbers on a stock soi table or are guys taking the time to readjust the soi to get the most from it? Not sure how many have seen the new tuning school di book but gives all the math and info on it. They claim they made 1000 hp or 850whp or so by doing this with lt4 fuel systems in this book. I know there is a lot on soi and other adjustments out there but not sure how much of it to believe. Seeing vengeance racing posing on camaro6 about picking up near 100whp by adding port injection to the Whipple setup over di and meth alone with no change in afr. What that tells me is the fuel timing isnt right on the di side of it so not using all the fuel it is getting. I know some are now using other machines on di to make sure that the fuel is spraying at the right time some how reading in the cylinder I believe rather then just taking what the wideband is reporting. Makes sense since if it isnt spraying when it can be used for power and burnt the wideband isnt going to see raw fuel leaving the port. If its over spraying for instance or at the wrong time and just blowing the extra fuel out and you think the systems just maxed out. I know with turbos they are also saying 100 more whp can be made due to the blower eating up so much power. I know on my old ats 2.0t some had claimed that 400 whp was it and by playing with my soi I was able to 50 whp out of it no problem at all and I was doing trial and error no math to it at all like the new tuning school books now have in them.
First 9 second 6th gen lt4 zl1 stock blower SHC SBE boost only.
2013 cadillac ats 2.0t Big turbo-gone
2007 tahoe 5.3 lsa blower on 14 lbs boost 6l80e swap 2009 os
2017 zl1 a10 big gulp/2 inch headers/ 9.55 lower/ e85/bigger hx /103mm tb / Synergy trunk tank and underhood kit/methanol injection with torqbyte controller and prometh pump / Jokerz performance R&D ported stock blower/ lme cnc heads /GP tuning custom cam. So far 9.30@150
LT1350 thanks for the reply. I never experienced the issues you listed after porting your TB as you indicated in a other thread, the problem of intermediate throttle lag I had was related to a bad katech TB. I replaced it with a new one and seems to cure my problem. I replace my gen4 e67 car to this new platform mostly to learn the new e92. I am not a shop just a car enthusiast and enjoy learning new stuff. I believe you are in the same boat as I with the same interests. I too bought the tuning school book and got really disappointed and return it the same week. it had no real explanation and only pointed you to add % to tables like a monkey on a keyboard witch would not work in my application. What save me is this forum and having a gen5 to play with. I do have a private garage of about 2000 sqft better equipped than some dealers, that helps. Guys like Higg/Ben/others/and yourself are the people who provided value by trial and error to get us all to the next level. As for SOI I am using the stock values with a small tweak of lowering some at the upper end. I found it cleaned up the black smoke an lowered my knock. Car is running 134 mph with good driveability/no knock stock blower 4200lbs car. This might not be the best approach but it work for me. to my knowledge there might be some benefits to massaging the soi to help fuel somewhat but there is no keyboard workaround of max out your fuel system. Cheers
Last edited by obd2; 03-17-2018 at 08:25 AM.
The new book update actully has some good stuff in it but the first version was stuff that was readily available on the forum. Im gonna sack them with tuning questions here soon and open a bunch of cases on e85 tuning my car and cam timing to get my moneys worth out of it..
Seems like the soi on many of these is over shooting the kr and black smoke so on. I found a lot of my random mid thorttle kr was cleaned up on my ats 2.0t by adjusting the soi and eoi. What car are you working with? I have been doing a lot of this on my zl1 trying to get as much with the stock tune and it just closes the throttle the more I try to get. I blocked the by pass abuse side of the diaphragm off and now on stock pulleys seeing 10-14 lbs of boost which is nuts but logging 170-195 kpa on the car now. It is shutting the throttle to compensate for the boost or until I finish my tune and get it in the car. But if I can make even 12 lbs with no pulleys thats saving me 800 bucks in a lower pulley by just setting my bypass screw up like the lsa as stock mine has tons of preload on it and blocking the abuse side of my bypass off.
First 9 second 6th gen lt4 zl1 stock blower SHC SBE boost only.
2013 cadillac ats 2.0t Big turbo-gone
2007 tahoe 5.3 lsa blower on 14 lbs boost 6l80e swap 2009 os
2017 zl1 a10 big gulp/2 inch headers/ 9.55 lower/ e85/bigger hx /103mm tb / Synergy trunk tank and underhood kit/methanol injection with torqbyte controller and prometh pump / Jokerz performance R&D ported stock blower/ lme cnc heads /GP tuning custom cam. So far 9.30@150
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