The fastest confirmed 1/4 mile times for a naturally aspirated Northstar V8 swap into a Fiero that I could find were 12.86sec @ 106mph. But that was using a manual trans if I'm not mistaken. Don't remember if the engine was stock.

I did a 260hp iron-head LT1 swap into a Fiero using a 4T60-E auto trans some time ago and that car ran a 13.2et @ 100mph. That engine was bone stock except for good exhaust, induction, and tuning.

Concerning weight, both of the above swaps are going to be the same or heavier than this swap. Assuming the same or more HP/TQ than the Northstar, this LS4/4T65-E combo should be good to a mid-12 sec et or faster, depending on traction. It's difficult for me to tell at this point how good this car is going to hook up because the outside temps haven't gone above 40 deg F here lately and we all know how cold rubber grips to cold asphalt. This LS4 makes more than enough low end power to boil the rear tires if you try to launch it hard.

 

The guy did a widebody kit also to add wider tires. Was a mean lookin' Fiero. Wish I could find pics for you from my old mags.

 

It's been awhile, but we have an update! Had the Fiero on a Dynojet and below are the results. I was hoping for a bit more at the wheels, but I'm pleased...very pleased.

As reported by Sinister Performance:







We executed 3 pulls:



As you can see from the results above, all three pulls were pretty consistant. I had them remove two of the pulls from the graph and just print out the best (HP) one:



Max WHP: 271.20
Max WTQ: 277.07

You can see on the dyno charts that the weather conditions were better than SAE ideal, thus the correction factor was less than 100% (meaning the engine was actually putting down more power to the dyno than these SAE corrected graphs show). Also you can see the AFR's didn't look bad at all (dashed line on the AFR graph represents 13.0:1). The beginning of the dyno pull did start out a little lean because they were easing into the throttle; but by about 4500rpm, the AFR's were near-perfect for what I wanted to see.

TiredGXP mentioned that people taking their stock LS4-powered Grand Prix GXP's to the dyno were getting anywhere from 230whp (a 24% loss thru the drivetrain) to 252whp (a 17% loss thru the drivetrain). If you apply the same loss % factor to the dyno runs I did today, then we can figure blkcofy's engine is producing:

317.3 ~ 336.3 @crank hp
324.2 ~ 343.6 @crank tq

Assuming a 24% drivetrain loss, that means the mods done to this engine have gained about 33hp and 20tq at the crank. Of course there's no way to measure the actual loss thru blkcofy's drivetrain unless we pull the engine and put it on a dyno by itself. Also we have to assume the dyno numbers I got today aren't going to exactly match the dyno numbers other people are getting.

 

Ryan, awesome work you did on that Fiero. Too bad you could make up a set of headers for our cars.

 

Great project. I love Pontiacs, have 4 of them now and cant get enough.

When the Fiero was spied in an issue of Popular Mechanics (83?) I told my GF and she bought one of the first ones off the floor, granted it was a 4cy/4sp but it was RED and sexy. Spending time in my dad's Delorean and also driving my sons 91 MR2 reminds me how much a kick in the a$$ 2 seat mid-engines are, even in stock form.

My brother built up a twin turbo 65 fastback so I can appreciate the work you guys do!

 

Nice. Now get it to the track! I'd love to see what it will run.

 

FINAL CHAPTER

OKAY, Okay, okay....I've had my car back for a little over 2 weeks now! I've gotten over the sheer thrill of having it back and can now provide an appropriately balanced report on the performance of one of the first stock LS4 swaps into a Fiero (affectionately known as a 87'/05' Pontiac Fiero GXP!).

Ryan is the man! This swap looks like it rolled off the assembly line!


Once I finally decide on what paint scheme I'm going with this fall, I will color match the engine cover to the paint job. But hell, one might argue to leave the engine cover off all together as tight and neat as it looks!


But there's something to be said, when people open up the rear deck lid and see the 5.3L V8 glaring at them and the "Ohhhh Sh*%!!" comments it creates. So the cover will probably stay!









I drove it from Indiana back to Cincinnati with a smile on my face from ear to ear. My wife was following me and my 6 year old daughter was riding with me, so I didn't really open it up. With no exhaust, it's a bit loud but not ignorant loud. The only time its an issue is when I hear it clearly shift from 4 cylinders to 8 cylinders via the DoD setup and whenever I go from a point of acceleration to a coast...you clearly hear the gurgle-gurgle from the exhaust. If you've ever gone boating, and witness some fancy cat put in his Twin V8 Cigarette Race Boat in the water...that's what it sounds like. One last Ohio e-check, at it's off w/ the cats and on with performance mufflers!! I can't be a "sleeper" car with the thunder of Thor crashing under the hood!!

Automatic shifts are deliberate and crisp. Using the paddles is actually kind of fun, but it kills my gas mileage as I tend to let the rpms run up to 3500-4000 before I shift versus it never goes above 2500 in auto unless I'm gunning it on the freeway.

The only changes that need to be fine tuned is to have the DoD shift much later in the power band, as I think it shifts a bit too soon. The other improvement is that while Ryan was able to turn off all the computer signals like ABS brakes, traction control, etc. the engine code has a default setting that whenever the tires have excessive spin, it throws the car in neutral, until you get back into it. So I've learned (learning) to ease into the launches with a slight tire chirp instead of stomping on it. Ryan is working with HP Tuners to fix both issues.

So, you know I just had to get this car to a 1/4 mile drag strip to really gauge the performance! This past Friday, I took my Fiero GXP to Edge Water Sports Park just outside of Cincinnati for it's Test and Tune Night. http://www.edgewaterrace.com

While I've been on closed tracks with my daily driver at least 7 times in the last 2 years, I have NEVER been to a drag strip. I'm nervous as hell, but excited. I try to lower my expectations, as I don't want to set my expectations up too high as I knew I would have to deal with my street tires, not being able to hard launch the car, and trying to figure out how to respond to a light tree for the first time. I've watched PINKS on TV and blew a few brain cells on video games, but that's about it! I wasn't sure what to expect. I convince myself that if I an post low 13's I'd be content, and with practice and luck, maybe I could break into the 12's one day. I was probably more nervous about crashing the drag racing community, more than anything else! I won't go into the details here, but the community is awesome! Interesting....but awesome!! All walks of life, all ages, all levels of education, income, and levels of soberness...but all in love with cars. It was great!!

So....how did we do?

I was able to get three runs in. The first run matched me up against a 2006 Mercedes Benz CL500 Coupe. I was freaking out, until I saw that it wasn't an AMG car so I figured I had a decent chance of keeping up with him. His confidence level and that of his friends when they saw he was matched up with my white wolf in sheep's clothing was at an all time high! It took me a while to figure out how to stage the car so that the two white lights engaged on the tree (this only gave the Benz that much more reason to stick his chest out) but I finally figured it out, and settled into the start. Results? Kicked his ***!!!!

R/T: .539 (he had a .442 R/T as a comparison)
60' : n/a my side wasn't working, but he had a 2.432
330: 5.510
1/8: 8.470 @ 83.76 mph
1000: 10.980
1/4: 13.128 @ 104.90 (the CL500 posted a 14.907 @ 96.88)

Recall, because of the code thing, I had to feather the start to avoid the shut down. But once it hooked, this car practically lept down the track! I'd do anything to run a 1/2 mile run, cause the car had plenty left and kept pulling the whole way. The sweet roar of the engine was only out gunned by the pounding of my heart against my chest! As I pulled back into line, my former nervousness quickly transformed into one cocky S.O.B.! As people walked by, I fielded all kind of questions regarding what the heck I had in this 21 year old "sheep"!

Race Two pitted me up against a 2005 BMW M3!! I won't lie, I was feeling a bit cocky still but the M3 driver and his crew actually had nerve to try to hide their giggling!! Oh, hell no! He gave his many friends high fives, and we pulled up into the start. Since I now knew I had a 13 second car, I had to wear my helmet. This actually gave the M3 a moment of pause! Of course, after the first run I immediately called Ryan to seek some coaching and driving tips, and report my results. He was very pleased, and was actually suprised I did so well for my first time at drag racing. We agreed to try to get aggressive with the next start to see if the track would hold my spin to a minimum and allow me to have a better launch. The M3 driver was smoking his tires like crazy. He was clearly no amateur, or so it appeared! I stomped...tires spun...car shut down! DAMMIT! I quickly got back into it, and to my disbelief...I was starting to quickly gain on the M3! Results? Caught his *** and beat him by .0618 seconds!!

R/T: 1.037
60: still racing on the side that's not working (he posted a 2.207)
330: 6.080
1/8: 9.037 @ 84.04 mph
1000: 11.537
1/4: 13.676 @ 105.33 (the M3 posted a 13.806 @ 102.59)

So, while I almost ran off the track cause I'm laughing so damn hard that despite a jacked up start, I still caught the M3 and beat him! But now I'm starting to get a little annoyed that I can't launch the car without fear of it shutting down on me. But before I could even get into feeling bad, as I get back in line for my final run, I'm met by crowds of people now even more curious than ever of what the hell I have as a power plant! They tell me the engine sounded awesome, and how the race announcer made a special point to call attention to the "little white Fiero with an attitude!". I spend the next 40 minutes answering questions and was even propositioned to sell my car twice. Of course there is NO AMOUNT of money that could get this car from me...at least not that night!! I thought to myself..I could get use to this!

My third and final run pitted me up against a late model Ford Thunderbird. It was an older guy, with race slicks in the rear and clearly something monsterous under the hood. At this point, I was happy to get away with two wins, so I was more focused on trying to launch without having the car shut down on me versus thinking I had a chance winning this one. The crowd was pretty thick at this point in the night, and I could easily see all the fingers pointing at my car as we pulled up. I think I was starting to get a bit of a fan club. This could really get addictive!! As I pulled up, I drove around the water to keep my tires dry, to see if that would do anything. Of course, the Thunderbird was laying all kinds of smoke and rubber. I tried not to focus on that, as I knew my goose was cooked on this race. Results? The Fiero GXP leaves it's first drag race UNDEFEATED!! About a 1/3 of the way down the track, he disappeared. I'd guess engine trouble or something. He finished, but well after the GXP!

R/T: .539 (the Thunderbird had a .233 R/T)
60: 1.895 ( I finally got on the side where the 60 ft worked!)
330: 5.442
1/8: 8.336 @ 84.80 mph
1000: 10.829
1/4: 12.961 @ 105.53 mph

So based on the 1/4 times, the calculators I've plugged the data into put the car at 272 HP at the wheels, and about 354 HP at the flywheel. This is consistent with the last Dyno reading Ryan made on the car. With a bit more experience, and fixing the wheel spin issue, there's no reason I shouldn't be able to get into the mid 12's on this car. I am one happy customer. It's not the fastest Fiero on the road...but it's a daily driver 1987 Fiero GT with one of the very first stock LS4s and it's all mine!!! [Ah-ha-ha-ha-ha-ha-haaaaa!]

Blkcofy

 

That is one awsome well done ride! I've always liked anything swaped into Fiero's... even stock they were pretty fun little cars.

 

Awesome times dood. Any plans for doing body work? You could put one of those lambo kits on your ride. It would make a great pair with the ls4 swap.

 

nice ! what kind of MPG's are you getting?

 

I think I need a Fiero with an LS4 if I didn't already have a project that needs finishing. I would be all over it.

 

i have always wanted to do a northstar swap... if i could only find a good deal on an 88 fiero gt

 

still think somone should throw one in a delorian that would be a time machine for sure

 

this is badass!

 

cool set up. I've always liked the Fiero.

 

isnt that preety much the same performance as a n* would give you.....
and did you fo the wiring?

 

Amazing fiero!!!! but the dyno torque numbers look really low. When i got dynoed i was at 266 hp and 325 torque. Maybe you are losing all the torque in the way the tranny is set up?

 

The problem at that time was that the differential score protection was kicking in. Had something to do with no ABS sensors being installed, so the BCM was telling the ECM to shut the throttle. May also have screwed around with torque management. I believe that Ryan, the tuner, sorted these things out shortly after BLKCOFY made his last post in this thread.

I can't believe some noob revived this thread about a completed swap to say a N* would give the same power.

 

Maybe if you did an AWD Fiero.

 

does anybody know where i can find some info on aftermarket performance for a northstar 4.6 engine?