Northstar Engines and System Technical Discussion Discussion, Northstar owner loosing faith in Cadillac Engine Discussion; Ive been reading this site and Im interested in the potential of the N*. Im new so Ill intro-97 sts ...
Ive been reading this site and Im interested in the potential of the N*. Im new so Ill intro-97 sts 115,000 stock bottom end with timeserts, I have radiused throttle body, modded air box-worked better than 4in K&N, ported intake( 3 hours a port at the injector) The heads have been shaved...10.4 comp? maybe no porting, the down time would have been too much. 3in catback to a true 3in Y into Bassani mufflers. It has the 3.71 ratio. It went to the Dyno and put down 226hp...my suspensetion is screwed and Im limited to 90 mph, I had to Dyno in second. I want more power without a standalone, its about 10.8-7 A/F at WOT
I'm not abig fan of the wheels either, but they actually don't look overkill like on most cars, but only cause it is black and chrome only. That exhaust where I live would be beaten flat in no time, but I like the way you think and admire the work done. If you ever go back to stock exhaust, get the 94 pipes if you want just a touch more sound. Cadillac thought they went too wild on the 94 and toned them down after that year. If you want to start over, I have a complete drivetrain out of a 95 Eldorado that has 91k miles on it. I got it from the insurance co with no title and have sold some of the parts, but the engine runs great. I'm hoping the exhaust fits my Seville or I will have to make some pieces.
I have no desire to hop mine up, it has plenty of spunk for an old geezer. I did buy the 4" intake off of flea-bay and was impressed with a marked improvement, but that will be as far as it goes, unless I can plug in a chip. I have offered a PCM to be used for research, but no takers. Good luck and if you need any parts that will come off a 95 Eldo, let me know.
I have been including my phone number cause you have to have 20 posts to pm. I'm gettin there though.
its weird...the first run of 222hp was with a ported intake but it still had the ski jump at the injector, the 3.5 pipe and filter-thats in the trunk. I had the pipe from the cat to the original Y 3in. I ran the original 2in mufflers and pipe, It ran almost a perfect A/F. I had the throttlebody radiused yet again-broke through the casting and epoxied, crushed my EGR tube and placed it back, spent more than 20+ hrs on the new intake from E-bay so it would be perfect. I had the mufflers put on before dyno day...(F body day) I had high hopes with all that it would yeild satifactory numbers...240-5 I was thinking of custom shortys and 2.5 pipe to the cat in my head, It was funny nobody had ever seen a N* on the dyno they said..."it has a 300hp motor, so it should put around 260-5 maybe 70" when it only put mid 20s they thought it was a piece of **it... after all that it didnt gain anything, and the comp went fat, WTF...
Our trannies use up about 23% of the power the motor is putting out.
Your engine is putting out 288hp. Something's wrong. Borrow some stock wheels and see what you pick up. Do the run in 2nd or 3rd gear.
Radiusing the throttle body isn't going to gain anything. Same with the intake mods shown. No air flows into the injector "pockets" you sanded down. If you wanted to make a useful change, you could have taken a look at the plastic manifold gaskets. On mine, they were sticking into the air flow by about 1mm on all sides. Multiply that by 8 cylinders and that could be a lot of lost power. If eliminating the "mouse holes" gained 5hp, this might gain 16hp.
Eldo, I have read your info on another thread about your intake , you have much respect on here and will give you the same. I wanted everybody to know I have genuine interests in this motor...I placed the new gaskets I ordered from GM up to the head to see if there was a difference, I dont remember a protrusion, I might have to pull it off and check again. As I look at... it the air travels down from the highest point to the injector and makes an immediate bend at the head, in my head, grinding out that ski jump and recontouring what I did helped the transition somewhat. but the real hinderence, is the way the runners are shaped...it goes from a huge box, travels up and around where at the top is shaped into a flat D shape, then opens back to match to the head. the D is the problem, I have bought a 2000 intake which bolts to the N* and the runners are huge, I would say 10-5% bigger, and would give more available air throughout. The problem is when I placed it next to my gaskets to make sure it bolted down right, it was way off...To make this work I would, drill and tap new holes, I would have to open the head to the gasket to match, then somehow attach the spacer and throttle, not to mention the rail and injectors, and make all sensors and vacume fittings work. a good Idea-but all that? would bigger runners hurt low end? would I see a gain from 4700 to 6500? not usable. As for the throttlebody, if you put a velocity stack on a carb you gain CFM, I opened it up because I felt I would see more CFM...you crack it 5% you get X amount of CFM I radiused it 360 degrees as much as I could breaking through, now I crack 5% I get the same amount of CFM plus the radiused portion which could be another 10 CFM. the best way would be for it to twist through the throttlebody, but with the blade and shaft it cant. I have experianced this on my mustang, LS1s do this, it worked for me...I feel 75mm is plenty...378hp on the 331ci at the ground at 7000 rpm, it should feed a 270 ci
I would piggyback with a Megasquirt, let the MSII run the engine ans let the regular ECU run everything else just tie the 2 harnesses together.
If your computer is going super rich at WOT then add some NOS (JK) that will give you a kick in the pants.
Actuall AF ratio to make good power and even leave it rich would be in the 12 to 12.5 range and thats what I run on NOS engines at WOT.
As long as the wheels nad tires arent over 5% larger than stock they shouldnt affect hp, just acceleration as they might be heavier than stock.