Corvette Z06 Forum banner

some thoughts and questions about the LS1/6 engine

1K views 12 replies 7 participants last post by  niphilli 
#1 ·
I have looking at the fourms of Ls1/6 cars, and noticed that the vast majority of tuners and racers emphasize in modding the fuel burning process and exhuast process... Especially after the Ls6 intake manifolds not many have thought about increasing the intake side effeciency... i know that the intake side of the engine is much more advanced as opposed to the exhuast side.. in other words the exhuast side is more restrective than the intake system and thus people upgrade catbacks before intakes, headers before intake manifold.. the MAF is good enough stock... i hope i am making my point?

i know that part of this is resulted in that technology has not given us promising intake mods.. hell if you look at all the 427 engines out there.. they are barely pushing anything above some radical H/C packages.. why? its becuase the intake side is not up to the job correct?

now, has anyone thought/explored the idea of increasing the effeciency in intake side? here are the goals for a setup that would benefit from this:

1- increase all over the rpm range
2- stealthy and i mean stock stealthy(anything worse than a Z06 is not acceptable)
3- would be easy to to drive around in stock tires
4- the car must have a sweet sound to it
5- a strong performer

this would make the best sleeper package.. people were talking about a stealthy head and cam packages.. and everyone thought it was not possible.. look at the Z its a perfect example.. now to achieve this goal how about this setup

1- FAST intake and bigger ported throttle body
2- corsa touring exhuast and Xpipe with high flow cats
3- a Better MAF
4- using a ram air intake
5- a comp cam that has high lift numbers and emphasizes the intake duration and maintain the same LSA as the 02 and up Z's
6- ported LS6 heads or getter a better flowing head
8- tubbing and 345's in the back


i dont expect this car to have more than 420 RWHP but i think if we emphasize the intake side of the car you will be building back pressure and increasing torque .. and the car will have nearly 400 RWTQ(which isnt low at all) this will make it a solid performer... it will defintley be streetable with 345's(it will sping but it will still go) the car would sound more aggresive but not obnoxious.. performance should be amazing.. the car would still pull harder from 2000 RPMS .. it will feel like the car didnot get an exponential power increase through the RPM range .. but rather a linear nice curve ... on the track.. this car should run anywhere from 11.6 to 12.2 and 120-124 depending on the driver... with stickier tires it could probably see some low 11 time slips... the car would still be able to benefit from a nitrous addition(especially from a dry setup)... road racing? the car should be very strong no matter what you gear your in...

does this seem like a feasible idea? i know most manufacturers turned toward forced induction to eliminate the need for improved intake systems.. but wouldnt it to get the same jump from a C5 to a Z06 on a Z06? can we say 485 flywheel horsepower in a TRUE driveable condition..

i am not expert i am just trying to point out somethign i noticed. and thought maybe you guys can help with... i am very interested to see what your thougths are on this.. hope someone can provide links to research in this direction

hassan
 
See less See more
#4 ·
Or conversely, if no one is doing it, could it be because it's not such a workable idea?

I personally don't know, but good ideas have a way of getting discovered. It's not like you'd be the first owner to look for more power.

jim
 
#5 ·
Hassan;
I took my car in last night for a new intake & 90mm TB.
I think GNX Guy just had a similar job done on his.
So there are a few of us that are addressing this issue.
You're right when you say that many of the 427's aren't putting out huge hp numbers and that they tend to become breathing impaired but, at least in my case, we specifically designed the engine package well below its maximum potential because, as a daily driver, reliability is much more important (to me) than wringing out the most hp from the engine. As for the need to sound stock - that's an eye of the beholder sort of thing, isn't it?. I'm not a stealthy kind of guy. :lol: I like the rear view mirror to vibrate at idle - in the car sitting next to me at a light. :D
 
#6 ·
2002Z06Yellow said:
1- increase all over the rpm range
2- stealthy and i mean stock stealthy(anything worse than a Z06 is not acceptable)
3- would be easy to to drive around in stock tires
4- the car must have a sweet sound to it
5- a strong performer

this would make the best sleeper package.. people were talking about a stealthy head and cam packages.. and everyone thought it was not possible.. look at the Z its a perfect example.. now to achieve this goal how about this setup

1- FAST intake and bigger ported throttle body
2- corsa touring exhuast and Xpipe with high flow cats
3- a Better MAF
4- using a ram air intake
5- a comp cam that has high lift numbers and emphasizes the intake duration and maintain the same LSA as the 02 and up Z's
6- ported LS6 heads or getter a better flowing head
8- tubbing and 345's in the back

hassan
Hey Hassan,
It looks like you have put alot of good thought into this. Here are a few points that I have learned over the years.

1. Intake manifold design is extremely difficult. It is easy to design a better manifold than the LS6 for Peak numbers, but for the most part an intake that makes great peak numbers KILLS midrange torque. The LS6 intake manifold actually does a pretty damn good job until you get above the 500 RWHP mark and start spinning the motor past 6500 RPM. I do think the LSx intake manifold is a better intake than the LS6, but only marginally (10RWHP). The good thing about the LSx is that it does not sacrifice any midrange torque.

2. Do not change the MAF. Our MAF is plenty big enough to support tons of power, changing the MAF usually creates a big tuning headache.

3. Dont waste your money on an xpipe and catback, the stock Z catback is fine and completely stealthy and LT header combos usuallly come with their own X pipe.

I like your ideas though. If I had the money and I were building a stealthy setup I would probably go with LG pro LTs, stock Z06 catback, FAST intake with bigger ported and polished TB, Halltech TRAP, Stock MAF, MTI "Stealth cam" or Thunder Racing "old man cam", along with a good set of ported LS6 heads. I think you could realistically make 430 RWHP with this package and be completely streetable, and probably emissions legal through cats :)
 
#7 ·
Hassan, I think the reason you don't see much in the way intake improvements is because the intake and TB are optimal for the LS6 and not much can be done in the way of increasing power without sacrificing power in one part of the power band. For folks with modded engines there are the FAST intake and ported throttle bodies that will show a significant increase in power.

GM spent a lot of dinero optimizing the intake system for the LS6 and that's one reason it will put out 405 HP. No small feat in itself. In other words, the stock components are pretty darn good. Just my 2 cents.
 
#8 ·
Z62: acually GNX was the guy that started me thinking about this... his setup is very VERY nice NA combo.. but cost would get in the way as a 427 is not ur usual mod..

niphilli: I see where your coming from.. LG's in place of a catback and an x pipe would also still maintain the stealthy side of it..as far as MAF.. i know its good.. but do you think that in the near future intake manifolds would flow better than the MAF would allow and thus have MAF that is somewhat restricted? i know the MAF is good but i just dont know how good... by this i mean .. could GNX setup be MAF limited? can he see a few extra horses and better breathing through a better(if such a thing exists) MAF? just a few things to think about

jub jub: exactly... i like the way GM has dealt with increasin power in its corvette engines... ive looked at the cam upgrades that they did to the C5 in the last seven years and found that their approach is MUCH more different than all tuners approaches... that is mainly due to the fact that they have to satisfy emmissions and pass driveability tests ... can we walk the path GM is walking?!

all in all ..i am happy with the kind of responses i am getting.. at least i am not way off and some thoughts are getting to you guys... hope more guys can chime in.. i am just trying to find a way to build a low horsepower monster(one like the Z06 350RWHP and can at least close in performacne to a viper(440RWHP) )
 
#9 ·
You'll need to be seeking BIG power before you'll notice an appreciable power increase over the stock LS6 intake. We made almost 450rwhp with GM 88958622 CNC heads/cam/Lingenfelter long tubes/3" Random Tech cats and exhaust with X-pipe on an '01 346 LS6 (stock shortblock, stock TB). Also, ATI's u/d pulley (excellent engineered piece). This in road-course tune, not drag, and VERY streetable.
The exhaust mod is with future displacement increase and/or poweradder intensions, while replacing the '01's "restrictive" cat situation. Added a little weight, but the future is brighter...
Your plan otherwise looks very promising...keep us posted of results.
As to tubbing, consider ACP's widebody rear quarters/facia...no floor surgery. Accomadates Pirelli's new 355/25/19's-14" tread, on 13" CCW wheels! Talk about bite...
 
#10 ·
ylostrk said:
Or conversely, if no one is doing it, could it be because it's not such a workable idea?

I personally don't know, but good ideas have a way of getting discovered. It's not like you'd be the first owner to look for more power.

jim
or maybe becuase it is the cheaper way? its easy to build a mover and shaker that performs well.. but from what i understand its VERY hard to bulid a true sleeper that performs just as well..
 
#11 · (Edited)
2002Z06Yellow said:
niphilli: I see where your coming from.. LG's in place of a catback and an x pipe would also still maintain the stealthy side of it..as far as MAF.. i know its good.. but do you think that in the near future intake manifolds would flow better than the MAF would allow and thus have MAF that is somewhat restricted? i know the MAF is good but i just dont know how good... by this i mean .. could GNX setup be MAF limited? can he see a few extra horses and better breathing through a better(if such a thing exists) MAF? just a few things to think about
I cant remember the exact numbers but I think the descreened 85MM maf that the Z uses flows well over 1000cfm...Plenty for N/A applications. I definately cant comment on GNX's setup because I dont know much about FI LSx applications, but I do think that Lingenfelters TT kits use the stock units and can easily make in the neighborhood of 700 RWHP with a boost controller.This is all great information though. The main restriction on our intake track is the inlet diameter of the manifold and TB diameter. IF you do some digging you will see that GM went with a bigger TB and revised intake manifold for the LS2 in the C6...Both of these modifications could have a good impact on our cars, and I think it will be a cheaper alternative to the LSx intake manifold and TB :z:
 
#13 ·
2002Z06Yellow said:
what about porting the stock LS6 manifold? do the LS2 TB and manifold flow better than a LS6's? or just better than an LS1?
Some tuners do mild port jobs with the stock LS6 manifold, but there is only so much you can do with plastic. The LS2 manifold and TB will definately flow better than the LS6, they are replacement parts for the old LS6 components as far as I know. I think the new TB is 85 MM and the the intake has an 85MM opening to match (speculation on the intake inlet).
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top