Originally Posted by La400

You are right, I spend over $15K in parts and work along with 4 years on the complete design of engine, transmission, rear end, handling, etc. It is all about balance of a set up, balance is the key to any winning car and the physics behind it. First you need to understand exactly what a engine is and how it functions, why it functions the way it does, combined with transmissions and rear axles. My business career has been in product development for many major corporations such as Boeing, 3M, US Military, etc. I have been building and racing cars since the early 70s. For a number of years held a E-Stock record in the mid 70s with a 73 Trans Am. Many a AMG, Hemi, TA and the such thought that a old Lexus sedan could not stay with them, but it did and beat them. Until you know exactly what you are doing, never say it can not be done. The first product I licensed to 3M, they ask me, why do you think you can do better than our 8000 engineers, 30 years later they still sell the product I developed. By saying it can not be done you have now limited your abilities and yourself from accomplishing it. Dare to dream of what is possible and you may just accomplish it. Say it can not be done and you for certain will not accomplish it. There is no magic here, just people that applied themselves at the race tracks, some winners, some losers, this is why you have such fine performance cars now days, because the old guys had a passion for what they were doing.

Originally Posted by La400

1. I do not always get what you are posting or since I have a business to run, may not have the time to answer your questions.
2. The factory put hundreds of millions in design and testing, do not ignore this. Work with it and not against it. Headers are not needed, factory turned exhaust manifolds work just fine for the street. That is traditional thinking, there is more advanced science on this.
3. Think along the lines of reducing HP robbing friction and internal HP robbing heat. The engine, transmission and rear end.
The 98 GS dyno at 235 RWHP, it only take 110 - 120 more HP for it to break in the 12s.
Unless you are willing to pay the price, then there is only so much you can do.

Originally Posted by JBrady

Guys, sorry to revive such and OLD thread but La400 is making claims that just do not add up. Yes, properly porting the heads along with the other stock components will make more power BUT how much? La400 claims 12.14 ET @ 129+mph in the quarter that is HUGE and flat out seems impossible. Stock the engine is rated 300hp/310tq with a vehicle weight of 3800lbs. Lets see what a drag calculator says for stock, remember this is with OPTIMIZED traction/drag tires and suspension: 13.58ET @ 99.53mph. Watch that MPH because that is the best indication of HP. Now, lets add 100hp our new numbers are 12.34 @ 109.55mph, again ignore ET unless you have optimized drag suspension and drag tires. So 109mph is a LONG way from 129mph. Now let’s drop to 3300lbs: we are now at 114mph. Now lets drop to 2800lbs: we are now at 121mph. Now let’s drop to 2300lbs: we are now at 129mph. So IF… and that is a HUGE IF… La400 added 100hp (equivalent to turbo/supercharge at 5psi) he would have to drop 1500 pounds off the car to run that mph. Does not add up.

Originally Posted by La400

Yes,
It is a gamble. The whole concept in this was to be able to take your heads, clean them up, put on and see results, target is 40 - 50 HP. I could lose power or I can gain. This was just a slight clean up to enhance what factory was not able to do in mass production. Always been effective in the past, maybe it will work on these engines. Continue to research, any advice is most appriciated.
Don't want affected:
Idle
Emissions
MPGs
- BUT-
In due consideration, applied since the introduction of the VVT systems in 1991, wild cams or even changing cams seem to be no longer needed to get 75-100kW per litre. The 98 GS400 is a hair over 75kW per litre.
Based upon the cams specs of the 1UZ-FE engines, combined with VVT of the GS400 program and its ability to alter cam timing as much as 60 degrees, heads were slightly street ported to enhance the current operating system of the GS400. Intake and exhaust cams can be retarded by 8 degrees for an improvement, the best improvement seems to be in keeping the stock intake cam and putting in a revised opeing of 18 degrees BBDC and closing of 18 degrees, ATDC exhaust cam, no where to be found by the way. There is additional gains by fitting in new cams all around, kills bottom end up to 4,500 rpms, but sure opens up top.
Factory cams from what I have read, have not taken cams and had checked yet, but will be done.
Intake opens BTDC 6 degrees
Intake closes ABDC 46 degrees
Exhaust opens BBDC 46 degrees
Exhaust closes BTDC 3 degrees
Overlap 9
Intake duration 232
Exhaust duration 229
Centerline 110 @ ATDC
Exhaust centerline 111.50 @ BTDC

In review of the improved flow properties of the ported heads. Very little improved over factory flow up to 250 lift, whereas large improvements in the 300-350 range. Combined this information with cam info. Looks to be a good match based upon power bands of current configurations of stock. I am hoping that the computer will learn to work with the new flow over time. So much is in the programing now days, if need be I may need computer upgrade.

Old saying, It is not how much you got, but how you use what you have.

Have a short block to work with on the side, any suggestions, they a excellent as they are, hard to find any improvements.

Hope this info is helpful to others,
Best for the new year.