LS1 280Z
1) Rev limiter is currently at 6,000. Is 6,500 feasible/practical/dangerous?
2) Intake is 7" conical K&M to MAF, right angle bend to TB.
K&N is right behind radiator. Is 7" K&N too small? Anything to be gained by pulling air from in front of radiator? ~how much?
3) Exhaust is shorty headers with 1.5" primaries to 2.5" collectors. @.5" pipes run to a collector 'Y' just aft of transmission to single 2.5" pipe last 5' into 2.5" 'turbo' muffler. Is 2.5" single pipe hurting? Should I go to 3" or 3.5" single pipe & muffler?
Dyno run was 311 RWHP with 326 lb-ft of torque. Torque drops like a rock after about 5,200 rpm.
Thanks!
If you have the stock valve springs and pushrods, then I wouldn't bump the rev limiter. My limiter is currently at 6700 RPM, but I have Comp 918 springs, hardened pushrods, and a low-lift cam (.510). Before installing the cam, springs and pushrods, I bent pushrods twice even with the stock limiter by banging the limiter once too many times on the first occasion, and a mechanical overrev from a 3-2 shift the second. Stock valvetrains on the LS1's suck, IMO.
Based on those numbers, I'm guessing you have a 2001 or newer LS1 motor with the LS6 intake.
Here is another dyno chart for comparison so you can get an idea where the torque drops off. Dropping at 5200 RPM sounds about right:
I'll leave the rev limiter alone.
Any opinions on the intake or exhaust?
You didn't mention..but do you have an U/D pulley? That will certainly help you as well.
Forget the longtubes. This is a Datsun and it's about a foot narrower than the F bodies. No place to run longtubes. Even the shorties are totally custom to fit the space available. Steering arm to rack runs through the driver side motor mount. Very tight fit side-to-side but lots of room front and rear and the important stuff is much more accessable than on a typical F body. Have to see to appreciate.
That intake setup should be sufficient but if you have the option to suck in air from under the car away from the radiator, that would be best. LS1s are very heavy breathers, and any restriction on the intake or exhaust can really limit performance.
As Ebbsnflows said, LTs are the way to go, however, I understand in a custom setup like you have, that might not be an option. I don't know how good you are with exhausts, but if you can get someone to fabricate for you a 1.75" header that is equal length, you will see even better numbers than you do now. For the BEST possible setup, you would want a LT header that is stepped 2-2-1, instead of the standard 4-1 single collector.
311HP/326TQ is right where a stock 01-02 F-body would be running. So it sounds to me like your engine is running as good as it could with no serious restrictions. As I'm sure you're learning the LS1 responds VERY well to mods, so the sky is really the limit. You can very easily reach 350-360RWHP with all boltons, you can easily reach 400RWHP with just a cam and boltons with stock heads, and with some stage 2 heads, cam, and all boltons, 450-475RWHP is possible.
So far, only one person has come close to 500 RWHP stock displacement, naturally aspirated without nitrous, but I firmly believe with one or two more years of LS1 performance development, 500RWHP will be obtainable on a more regular basis!
Welcome to the board, and good luck with everything, and for the love of god....give us some pictures of that setup!
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Thanks for posting the pics for me. One obvious thing about the first photo is that there is a lot more room under the hood than most folks give the little Z cars credit for. The only real space problems occur down at the frame rails on both sides, especially on hte driver's side where the steering gear arm goes down to the rack. In this installationit actually passes through the engine mount. Nice thing though is that all the spark plugs are easily accessible.
Routing the K&N in front of the rad is definitely a good idea. I would use the largest unit you can find. Also descreen your MAF if you haven't already and run do the throttle body coolant bypass.
Sounds like a neat project! Congrats!
ps- Just swap in a set of 2002 LS6 springs if you want to raise the limiter to 6600rpm. Those springs will easily handle the stock cam lift and duration at that rpm.
If you dont mind me asking,exactly how much do you think this whole project is going to cost you? Just wondering how much money Im going to spend on the perfect combo of car and engine. Thanks for posting that link, looks like Ill be spending most of my time on its forums. Cant wait to see some times.








