[NYblack1le]

Originally Posted by BlackbeastSS2

I am at 526 NA on pump 93, yet to do my E50 - E85 dyno run yet.

You can read my mods on signature. I went with the TSP EL 7 cam. It’s a very heavy sounding cam. My heads are shaved.

Cam Specs: 23x/24x, .645"/.635", 113 LSA

To make the power you want you need to change bore and stroke dimensions. EI: make the piston travel shorter. It’s not cheap to do this.

Katech does a nice job at converting a 6.2 to a 427 with 701 HP.

https://www.motortrend.com/how-to/16...ed-lt1-engine/

Keep in mind every dyno reads different and the proof in the pudding is a time slip. The dyno number is only a tuning device but an excellent gauge at power levels.

You don’t need to touch the bottom end. Compression is king. You can run the biggest cam there is but without correct compression you’re pissing in the wind.

[LT1ornothing]

Both ways can get you there: high compression stock cubes or stock compression with more displacement.
The OP was looking for an NA SBE LT1 600rwhp build on an automatic. It can be done, but that recipe requires some ingredients that the OP does not want to use. I also get a sense of some denial and false hope that an LT2 intake and LT5 throttle body could ever flow what is required for the OP's goal. Sometimes you just have to see it for yourself I guess.

[sr71bb]

Originally Posted by 1LEornothing

Both ways can get you there: high compression stock cubes or stock compression with more displacement.
The OP was looking for an NA SBE LT1 600rwhp build on an automatic. It can be done, but that recipe requires some ingredients that the OP does not want to use. I also get a sense of some denial and false hope that an LT2 intake and LT5 throttle body could ever flow what is required for the OP's goal. Sometimes you just have to see it for yourself I guess.

Well it is not so much as false hope as if I cant get to the 600RWHP goal then 550-575 would be fine. Thats plenty for road racing purposes.

I appreciate the input from all of you guys. I KNOW a whole lot more about a boosted application than I do about NA so this is helpful.

[BlackbeastSS2]

Originally Posted by NYblack1le

You don’t need to touch the bottom end. Compression is king. You can run the biggest cam there is but without correct compression you’re pissing in the wind.

Everyone builds differently and your right compression will get you there. But, my build Nitrous is my Ace in the hole.

[ULTRAZLS1]

On an aggressive heads cam setup the lt2 will be more than 10-15 hp behind a ported msd. Probably around 30

The 95 tb will be fine IMO. Not leaving much on the table with that in the 6-700 hp range

[sr71bb]

Originally Posted by 1LEornothing

Both ways can get you there: high compression stock cubes or stock compression with more displacement.
The OP was looking for an NA SBE LT1 600rwhp build on an automatic. It can be done, but that recipe requires some ingredients that the OP does not want to use. I also get a sense of some denial and false hope that an LT2 intake and LT5 throttle body could ever flow what is required for the OP's goal. Sometimes you just have to see it for yourself I guess.

Well my understanding is with every FULL point bump in compression you can pick up about 3% in power. So a 13.5 to 1 LT1 should be good for a 25-30HP improvement assuming you started around 475HP (11.5 to 1 stock compression).

Running E85 should provide enough octane to support that compression level in my case. No doubt you would probably have to run 100 octane if E85 was NOT available.

[thegoat]

Originally Posted by ULTRAZLS1

On an aggressive heads cam setup the lt2 will be more than 10-15 hp behind a ported msd. Probably around 30

The 95 tb will be fine IMO. Not leaving much on the table with that in the 6-700 hp range

This is correct

[17camaroSS]

You’re going to be in the 540-550 area with that setup. Also the higher you go with compression the less gain you’ll start to see. You can run 14:1 on pump E with no issues.

[KingLT1]

580-600whp has been achieved several times with a ported MSD on E85. RPM has at least 3 cars now, Pray Performance has done several...GPI has some too.

Ported MSD
Ported 95
Good Heads(FED/Pray/CID)
Compression bump (12.5 )
Stage 3 cam (230's on the intake)
E85
Proper tuning

You need more compression with larger cams to gain back some low end efficiency since you lose a lot of dynamic compression. This is what effects tip-in throttle and driveability. It also nets more power...with E85 compression can be raised quite a bit, but you have to be careful how high you go if you ever want to run pump gas.

[JSH]

Hennessey, Lingenfelter, KaTech and others have answered such questions long ago. No need to reinvent the wheel, just hire the expertise.

Originally Posted by sr71bb

Guys I am curious as to what cam was used in the highest HP stock block that you have personally seen??? What basically I am looking for is a naturally aspirated LT1 that makes between 580 and 600 RWHP.

I did a search but came up with nothing that really helps. I had a custom ground cam done that in THEORY should do that but what I am looking for is what someone has actually had personal experience in seeing that number in the REAL world LOL

I know LME and others had made as much as 800HP on a motor dyno with LT stroker motors but I an looking to do this 580-600 RWHP with a stock block. i already acquired some very good heads and am currently, running LT2 manifold, LT5 Throttle body, E85 and 2 inch KOOKS headers. Current power level is 475/480 HP/TQ with stock heads and cam.

THANKS

[s346k]

Originally Posted by sr71bb

Yeah my LT2 manifold and LT5 throttle body are BOTH ported so I am not too concerned about 10-15 HP loss vs MSD although no doubt there would be SOME gain with the MSD.

do you have any 1/4 mile passes with that setup?

one thing to heavily consider is that peak dyno numbers don't tell the entire story on performance.

i don't think a ported stock cast cyl head and LT2 manifold is going to get you anywhere near 600 on a legitimate dyno.

how much are those heads milled? what gasket are you planning on using? stock valve? quench?

edit: do you care to share the cam specs?

[thegoat]

Originally Posted by JSH

Hennessey, Lingenfelter, KaTech and others have answered such questions long ago. No need to reinvent the wheel, just hire the expertise.

Where?

[sr71bb]

Originally Posted by JSH

Hennessey, Lingenfelter, KaTech and others have answered such questions long ago. No need to reinvent the wheel, just hire the expertise.

Well the problem is 99% of the people you mentioned DONT do road racing applications. Thats an entirely different ball game.

For instance it is NOT a good idea to use a higher stall speed convertor generally in road racing applications because you dont want to affect the shifting characteristics. The A10 does a wonderful job in TRACK MODE in making sure the car is in the RPM power band. RARELY even on slower parts of a road course is the engine rpm EVER below around 4000 RPM.

Higher stall speed convertors inherently have more slippage built into them which is great for drag racing to help get the car off the line faster but it is not something that is desirable in my application. The slippage results in higher tranny temps as well.

I am rethinking the CAM selection but I will post it up here along with the DYNO when it is installed.

[JSH]

Don't know where you got that. They all build primarily street cars for all types of track applications. Look at https://www.lingenfelter.com/events.html for example.

Originally Posted by sr71bb

Well the problem is 99% of the people you mentioned DONT do road racing applications. Thats an entirely different ball game.

For instance it is NOT a good idea to use a higher stall speed convertor generally in road racing applications because you dont want to affect the shifting characteristics. The A10 does a wonderful job in TRACK MODE in making sure the car is in the RPM power band. RARELY even on slower parts of a road course is the engine rpm EVER below around 4000 RPM.

Higher stall speed convertors inherently have more slippage built into them which is great for drag racing to help get the car off the line faster but it is not something that is desirable in my application. The slippage results in higher tranny temps as well.

I am rethinking the CAM selection but I will post it up here along with the DYNO when it is installed.