Hi guys! Still thinking there is more to squeeze out of the car to put me up there with the stock C6s. It is not a daily driver, but I do not want to lose drivability either.
Current mods:
LT headers
Hot cam
Tune
Electricwater pump
High flow cats
Corsa exhaust
Heads and intake have not been touched other than valve guides installed and new springs.
I do NOT want to add nitrous or change the rear rear from the stock 3.45
Current HP is 341 rear wheel horsepower or just over 400 the GM way using 15% loss.
1996 Red/black/black LT4 convertible with a couple of mods
1991 White on Red ZR-1 #1746
1996 Yellow/black/black LT4 convertible (1 of 11)
1996 Grand Sport Conv't #750, F45, black interior, every option Sold, but looking for a replacement
lets assume, as has been said forever, that an engine is basically a glorified air pump.
look at your airflow in reverse.
low restriction exhaust: done
high flow cats: done
headers: done
larger intake/exhaust valves/ported heads: not done
cam: done
intake manifold: not done
throttle body: not done
mass air flow sensor: not done
mass air flow housing: not done
air filter and air filter housing: not done
The components making up the exhaust side of your engine have been maximized.
Most would argue that aftermarket heads ported with bigger valves would be the biggest single improvement; and few would deny also the most expensive.
For further improvement, that leaves the intake side.
On the intake side, when tested on a stock LT1, a Mid America Motorworks Mass Air Flow Housing (PN 616-002) , VETTE MAGAZINE had this to say:
"We were stunned when the Dynojet registered improvements of 9 rwhp and 7 rwtq precisely what Mid America claims for the unit in its catalogue....Even at its regular price of $99.95, this ones a steal"
I would postulate that on a mildly modified engine such as yours, you would see even more of an improvement.
Good luck, let us know what you decide and how it works out for you.
(as recommended) Your current set-up would really love some nice (High-End) Cylinder-Head port Work......IMO, (& experience) you really couldn't go wrong with having either www.advancedInduction.com , or Lloyd Elliott @ www.elliottsportworks.com , bring your factory LT-4 castings out nicely.....And (as recommended), a custom grind cam can also help to maximize the combo.... But in all honesty, "If" your really happy with the Hot-Cam (IE: the way it drives /and the decent mileage it still yields), I wouldn't worry about it one bit, I would leave it in...The Hot-Cam will still actually be VERY close (at the track) to what any of the "still streetable" / "similar spec'd", custom grinds will be......this will be especially the case, since you mentioned that you Do Not want to go ANY deeper with your gearing (which of course limits how much more cam timing you can get in there, before you quickly start trading off low-end torque, for upper RPM power)........Having the LT1/LT4 intake manifold ported at these power levels commonly yields a 1-2 MPH trap speed gain without any real torque loss(so it is beneficial to some).....You could then go for a 58mm throttle body at the same time, so that you'd pick up some more substantial power with the two changes at once.....Also, there is honest power to be gained with a well functioning CAI or Ram-Air set-up.....After trying just about every CAI & Ram-Air set-up possible, I stayed with the one from Breathless Performance...it was the only unit that yielded consistent 2-3 MPH differences in my trap speed.......Anyway, this is the route I would go(and have gone in the past)....With everything mentioned (basically FULL bolt-ons) you should be VERY close to the 375-390 RWHP mark even with the HotCam left in place...and trap speeds could easily fall between 118-121 depending on your locals tracks air....see-ya later C6, LOL..........PS: Also, at all costs...stay away from any products that physically change the MAF housing size.....while some (Bone Stock, factory tuned) cars can pick up a VERY small amount of power, because it's lessening an "overly rich" factory condition during power Enrichment / full throttle.....On the other hand, MANY MANY people with non-stock cars have power losses , and peculiar tuning difficulties......Any of the good tuners (even the good mail order guys are SUPER familiar with this) and recommend going back to the factory MAF housing if it was changed...............
Last edited by 95NOSvette; 11-10-2009 at 12:24 PM.
With the exact same mods that you have (except I have a Magnaflow exhaust instead of Corsa) mine made 354rwhp and 348rwtq with a spot on tune. Different dynos will produce different results, but there may be a little bit more left in really dialing in your tune.
__________________ '96 CE - LT4 Hotcam, 4.10 gears, exhaust, and a little nitrous...498rwhp/547rwtq
On the intake side, when tested on a stock LT1, a Mid America Motorworks Mass Air Flow Housing (PN 616-002) , VETTE MAGAZINE had this to say:
"We were stunned when the Dynojet registered improvements of 9 rwhp and 7 rwtq precisely what Mid America claims for the unit in its catalogue....Even at its regular price of $99.95, this ones a steal"
I would postulate that on a mildly modified engine such as yours, you would see even more of an improvement.
Good luck, let us know what you decide and how it works out for you.
I've ordered this part...it's on sale for less than $60 shipped, so we'll see.
Sounds like you haven't heard the saying 'all the power is in the cylinder heads'. Get them ported and you will see the biggest gains vs any mod you currently have.
Cylinder heads cylinder heads cylinder heads!!!! These guys are right. Efficiency is all in the heads, TQ HP and MPG comes from good heads. Its the low lift flow that really gives you the kick in the butt and makes for less needed duration in the cam to make it rev due to efficiency increase which equals more HP on top of the benefit of the new airflow. But keep in mind your whole induction and exhaust system will affect the actual flow. If possible flow the intake throttle body etc. on the heads before you assemble so you know whats actually going in the engine, then you will see what you need to improve next. Can't say enough good things about AFR Comp eliminators, go with something excellent out of the box and never look back. Then it all becomes unbolt then bolt on affair. Instant gratification, no waiting for the head porter replacing guides, milling the deck, new locks retainers, new springs, etc. Thats why new you can hardly complain about the price difference because there isn't much of one if you are going to do it properly. I am also a head porter so I have practical experience and knowledge. Like other said its the biggest gain for the money and if you want to make power its the most effective way to go. Also another fact the combustion chambers and port shapes are also constantly being revised and improved which will make noticeable improvements in efficiency and power. Good luck with whatever you do.
Corvette Store
More power out of the LT4?
)....With everything mentioned (basically FULL bolt-ons) you should be VERY close to the 375-390 RWHP mark even with the HotCam left in place...and trap speeds could easily fall between 118-121 depending on your locals tracks air....see-ya later C6, LOL..........PS: Also, at all costs...stay away from any products that physically change the MAF housing size.....while some (Bone Stock, factory tuned) cars can pick up a VERY small amount of power, because it's lessening an "overly rich" factory condition during power Enrichment / full throttle.....On the other hand, MANY MANY people with non-stock cars have power losses , and peculiar tuning difficulties......Any of the good tuners (even the good mail order guys are SUPER familiar with this) and recommend going back to the factory MAF housing if it was changed...............
A little bit of tweaking from AI will put you in a whole new neighborhood power wise.
