Sorry to bother you again but i am kinda fascinated with your car. i know you said you would really like to see that magical 400rwhp mark with ur car and i htink you can do it. To be quite honest that is exactly what i want but i am kind of waiting to see what it takes you to get there!

My questions are...last time you dynoed you got the impressive 380rwhp but this was also in late May correct? the heat could not have helped your dyno very much

You also mentioned something in that post about not installing your new injectors yet cause you wanted to dyno it one step at a time or something similar.

Have you done any tuning since your last dyno?
What size injectors are you running now? and how big are the new ones you were contemplating putting in?

I am wondering that if between putting in your new injectors, tuning it accordingly and perhaps dynoing again on a colder day more into fall with maybe some ice on the intake if you couldnt hit the 400 mark. you are so close.

Also... if you dont mind, would you tell me what you ever found out about those "variable" rockers? are those worth anything? your 1.7 RRs seem to prove their worth with a 14rwhp gain but im just curious what made you choose them over the variable ones.
Thanks a lot in advance Nathan! I appreciate it.

 

 

I am only speaking from my stand point. This is not a flame against Nathan, but more of a reality check for you. I looked hard at the Hot Cam for some time and it is a very potent little cam. However, Nathan is the only one that I have ever heard of putting down those numbers. I also believe that Nathan has "access" to a dyno. Then there is the issue of true dyno numbers. There are helpful ways to get bigger numbers on a dyno and then the dyno itself. All I am saying is that there are variances and Nathan has obviously put in the wrench time. I wouldn't expect the same performance just because you have similar parts. I do believe in following suit and using a proven combo though. Good luck!


[Modified by ANTI VENOM, 9:02 AM 7/7/2004]

 

ANTI VENOM, i see what you are saying and understand completely. However, i am just looking for different people that have made 400rwhp with LTX motors with little or no head work. I want to do a setup with 400rwhp here in the near future and i am looking for different people that have already acheived this and how they did it. No offence meant. Not trying to flame anyone just trying to make myself understood

 

I am not sure what you consider "little" head work, but Nathan has it. I believe that he has CNC heads from Total Engine Airflow. They may not have special welding or major mods, but they are worked over. I hope that you are not expecting 400rwhp without head work. It could probably be done, but the cam would be unrealistic on the street. Starting with LT4 heads would surely help. Good luck!

 

1996man,

I've run various different injectors in the past but I've eventually just given up to the fact that Ski is right, 24's are more than enough for what I need and the driveability is much better with those than with larger injectors.

As for rockers I've had 3 different types now:

Crane Cams Gold rockers which are basically the same thing that came in the hot-cam kit.

Scorpion 1.7 rockers - aluminum rocker, 1.7 ratio, 7/16th stud. I ran these for over a year, I just swapped them last weekend.

Comp Cams Hi Tech 1.8 Rockers - a steel roller rocker, 1.8 ratio, 7/16th stud. I just put these on this weekend, haven't dyno'd it yet.

I'm not sure what you mean by "variable" rockers. I honestly don't remember every posting anything about such a thing. There is a such a thing as a variable lifter, but I don't think they exist in the hydraulic roller variety.

As for using the dyno and/or cheating it. Well frankly, that's cheating. Although weather will have an impact on dyno numbers, that's why you have the SAE correction factor. If I was to turn off the correction scheme my car would make over 400 hp, but since everybody looks at SAE numbers, that's what I use. Ice on the intake? Completely pointless on an LT1, I know because I tried, made the same horsepower as it did without.

As you all know, I dyno a lot, and it is at TEA. I know the guys who work there. I do whatever I can to help them out, and I try to send them as many customers as I can. Thus a few hours of dyno time, after hours, isn't usually a big deal. For example, if these 1.8 rockers give the gain I expect, there may well be some people who want to buy some. Since TEA can sell them cheaper than Summit and still make a profit, it somewhat makes sense to see what kind of gain they give me. If I send them one or two customers who want these rockers, the dyno time is paid for. So that's the story on that. I get to dyno a lot, and because of it, I get it honest. I don't want to get a fake 400 hp, I want it to be 400 hp at any given day, which means any nasty hot weather we may have.

As for my cylinder heads, ANIT-VENOM is absolutely right. My heads are still my original LT1 castings, but they are very far from stock. They have been fully CNC machined with a finishing hand polish. The valves are Ferrea, undercut stem, swirl polished stainless steel, 2.00" intake / 1.56" exhaust. The valve springs are Performance Engine Products double springs, very large, capable of high lifts and high pressures. Titanium retainers, 10 degree locks, etc, etc.

Everything from the final hand polishing to the back-cut on the valves was discussed at length in order to give me exactly the cylinder head that I wanted. As you can see, the results are fantastic.

Also realize that in combination with the heads is the entire system. The cam, heads, headers, timing set, water pump, lifters, etc all work together to make horsepower. Change just one component and you may well mess up the entire combo.

 

WOW! thanks a lot for the info
ANTIVENOM: I DO have hte LT4 heads to start with and i just mean that i dont want to spend the 1400 bucks CNC in south fl wants for a stage III P&P job. there is a local speed shop here in town that has experience in lightly porting heads and i may have them do some slight work on my LT4 heads but thats it.
Nathan: i know you started out with an LT1 but what compression are you running at now? i am very curious to see what your new rockers do for you. are you ever planning on putting anyhting hotter than the hotcam in? or are you just wanting to see how much power you can make with that? just curious. Thanks for all the info so far!

 

ttt

 

My compression ratio is probably a little higher than stock.

The CNC work on my heads does some bowl work which makes it a slighly bigger chamber. To compensate for this, and to give a very clean mating surface we milled the heads a little bit, which will effectively decrease the chamber size somewhat. My valves are larger than stock and have a flat bottom as well, instead of a dished bottom like the stockers, this will make the chamber smaller still.

The stock head gasket for the LT1 is .049, I installed the fel-pro .039 gaskets, which will further raise my compression ratio.

Unforutnately I didn't think to CC the combustion chamber, so I have no way of calculating my actual compression ratio. Stock would have been 10.5:1, I feel like it is above that, but still well under 11:1.

As for a different cam, I have no plans on swapping the cam any time soon. This car is my daily driver so I have to maintain good street manners. I could easily get a cam that would make more top end power, but the loss in low end torque would not be acceptable to me. I want to get 400 horsepower out of a Hot Cam just because everybody says it can't be done.

 

I feel exactly the same way! Thanks again for the info. I eagerly look forward to your results