Steve91T

That's really interesting. I had no idea about the physics involved.

Ok, I'll use a stock cam and LT's.

Would you guys recommend LS6 springs because of the rpm I want to spin to?

DavidBoren

You are going to want some good springs, Brian Tooley Racing Platinum dual springs being the most preferred, but PAC 1218 or even Comp 918 springs are better than the LS6 springs.

Steve91T

Great thank you.

93Polo

iTrader: (5)

Following this as I've been intrigued by the class and it is an interesting topic.

My '00 C5 did 340 rwhp upper 330s rwtq (wish I could find the graph) on a LS6 intake, blackwing air filter, stock airbridge, ported stock TB, TPIS LTs with stock cats, stock mufflers. A late C5 LS1 or '04 GTO would likely get you the preferred LS6 block/intake getting you in the ballpark. If needed you could restrict the motor with a LS1 intake. I agree with getting the 1.75" primary LTs as it would increase torque across the band.

dailydriver

Which valvetrain was installed into the latter 243 heads on the '01 & '02 f body LS1s??

Was it the basic, standard, same as the earlier 241 casting; valves/springs, etc., or did they get the FULL LS6 (lighter/sodium filled) valve/spring treatment??

dailydriver

In your opinion, does the LS6 cam, when used with either LS6, or other mild springs (Comp 918s/PAC 1218, etc.), and a 241 head, come under the above rule?

Which cam would you run with the stock, un-ported 241s, if you HAD TO run a stock iron manifold, or tubular shortie header, and did NOT want to give up that lower to middle torque band??

Steve91T

I thought people would be jumping all over this question. I'm interested as well.

Darth_V8r

iTrader: (4)

243 never went into a factory F body.

big hammer

241's were the later ls1 casting. 243's were ls6.

The ls6 springs we're made to control lighter valves at high rpm than what the ls1 has. I would go with a better beehive spring.

The ls6 cam also accepts 1.8 rockers really nicely too.

dailydriver

Somehow I always thought that the latter '01-'02 f bodies got the 243 heads from the Z06 along with the LS6 intake?

Did they get the LS6 block, along with it's intake, but NOT the LS6 heads???

93Polo

iTrader: (5)

Some f-bodies had LS6 blocks as did some nonZ06 C5s made in 01-02. I know all 01+ C5s had LS6 intakes, not sure about the f-bodies but I believe it was the same. LS1s never received 243s. Only Z06s received the LS6(engine) from the factory, all other C5s were LS1s (engine).

https://ls1tech.com/forums/generatio...ck-f-body.html
https://ls1tech.com/forums/new-ls1-o...ls6-block.html

JRP (wrote many of the FAQs used for years here) posts that all 01-02 F-bodies had the LS6 intake:
https://ls1tech.com/forums/generatio...our-fbody.html

dailydriver

^^^THANKS for that info.

I knew about the C5s and what they got, but was not sure about the latter f bodies.

Martin Smallwood

iTrader: (2)

LS6 cam would work because it has very little seat to seat overlap and it has large amounts of negative overlap @.050. I would use a PAC 1218 drop in spring to give you a little bit more seated and open spring pressure so you can rev the engine past 6500rpm if you needed while racing.

How do they measure your power output?

Steve91T

Mr Smallwood. I'm honestly still torn, and here's why. If I run the stock ls1 cam, I'm going to need to buy LT's, a catted Y pipe, have a custom exhaust welded up and install aftermarket springs. If I use an ls6 cam with ls6 springs, I can run stock manifolds and a stock y pipe.

How much of a difference between the two options? Because to me, the 2nd option is a lot cheaper. Is the difference in mid range torque worth the difference in price?

dailydriver

Thanks!

I believe that NASA uses a portable/mobile Dynojet, and they do 'correct' for the test conditions. (But maybe Steve can confirm or refute this?)

Steve91T

Yeah all I know is if you run up front, I can expect to get dyno'd. So in other words, I'll probably never be dyno'd

The rules for TT3 use an average rwhp calculation. Here's what it says in the rule book.


The following ten (10) data points will be obtained from the Dyno’s 50 RPM data export numeric RPM/HP table printout:

Horsepower at: 500 rpm, 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm greater than Max HP rpm Horsepower at: 500 rpm, 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm less than Max HP rpm
(If any of the above data points at higher RPM than Max HP RPM do not exist due to redline, then those potential data points will not be used in the calculation of Avg HP.)
The three (3) highest data points of the above ten (10) will be used in the calculation below:
Avg HP = Max HP +(sum of the three highest data points) 4
note: (It is anticipated that in ’17, this formula will be adopted for all TT/PT/ST classes)

DavidBoren

Honestly, to do this right, you have to buy the components for the exhaust. That is the correct thing to do. If you do not want to, or just flat out refuse to, then just throw the LS6 cam and LS6 springs in there with the stock manifolds and see what that gets you.

OR...

Use the LS6 cam, the PAC1218 springs, and a real exhaust.

I'm never the guy to tell people not to ask for help, but if you are going to ask for help, it may behoove you to heed the advice given in response to your inquiries. Otherwise, it seems your mind is already made, and all these questions are just bullshit posturing.

Inflame

iTrader: (2)

Hey,

Yes I do - https://www.youtube.com/channel/UC9Y...XA3HpCjv3B_PmQ

I don't update it as much as I'd like. The most recent progress is the car is 99% done, needs corner balance, alignment and a tune.


Here is my project log on bimmerforums

http://www.bimmerforums.com/forum/sh...Car-S50-to-LS1

Steve91T

There's a ton of great information in this thread and it will all help me make my decision. I was pretty much set on LT's and an ls1 cam when daily driver asked Mr Smallwood if he had to use stock mani's, what cam would he use. He said LS6 cam with Pac 1218 springs. To me, it sounds like that might be a great combination and would be easiest on the wallet.

My understanding is the ls1 cam with LT's will be about the same power as the ls6 cam and stock mani's. The difference being in low and midrange torque. I just wanted to know how much of a difference.

Martin Smallwood

iTrader: (2)

The LS1 cam and LT's with a good full exhaust will make more power IMO than a LS6 cam and stock manifolds.