This thread kinda started in General, so I'm moving it over here for more talk about stuff thats technical. Took it to the track this weekend for its first little shake down and here is what I've found. I also have a few pics of the front suspension.
First things first, the car did drive pretty great!
Front end: There was some loose suspension parts somewhere in the car, most noticeable on left hand braking turns.... No smoking gun on this yet but I did find a loose tie rod end on the driver front. As you can see in the pics the passenger front has a bump steer correction kit installed... yet there is a stock tie rod end on the driver side that was loose due to a loose jam nut.... oh well. Otherwise the front end felt good, shocks are in good shape and although the steering rack seems to have a pile of gravel in it overall worked fine. I also was able to find that the knuckles I have are HT drop knuckles specifically designed with 88 brakes and 87 spindles.
Rear end: The Maxima koni shock conversion seems to be working just great. However I did have the camber adjustment in the knuckle slip and I lost all the negative camber I had back there... Easy fix and luckily it only caused me to slip off the track really pushing a slow right hand turn. I suspect the rod end 88 lat links are starting to wear out a bit but I havent looked that close at them, but they felt ok on the track so far. I plan to replace these soon.
Drivetrain: The LS1 throttle body and super cool headers are likely causing issues with the tune. The cooling system was GREAT i mean super great, but I had issues keeping the thermostat in it, it kept twisting and popping out of the stock fiero thermostat housing that was welded onto the 3.4 tdc stuff. That caused issues because the tune became much better the warmer it was. I looked at the chip in the ecu and it looks stock, but it could have been UV erased and reflashed (highly doubt it). Previous owner swore to me this was tuned well when he sold it to me. I ordered a chip kit and will do my own tune for this soon. The symptoms were a complete power cut if I gave it more than 15% throttle under 3500rpms, and a severe drop in power after 5000rpm.... Which was nice because the absolutely flawless Quaife LSD equipped W41 transmission let me keep it right in the sweet 4000-5000rpm spot all weekend without much effort. Trans also shifted better than my s2000 somehow even with crappy cables and stuff... I commented I couldnt mis-shift that car no matter how hard I tried to lol. Was pretty quick when it was running right!
Brakes:
My gosh the brakes sucked. EBC yellows on some old beat up rotors were a horrible choice but I was able to turn laps so I am not complaining too much here. I am in the search for a new brake system that is for sure. I have a unique situation with the drop knuckles and an absolute hatred for the 88 calipers... I refuse to use these as they are expensive, poorly designed, and there are absolutely no performance pad options for them... at least without really begging some of my friends at PFC. I would love to have a conversation here with anyone that would like to suggest a good combo, but after a few hours of research I've settled on the standard corvette rotor upgrade commonly used with stock calipers, but putting on the $110 each brembo CTSV calipers with an adapter plate... both front and rear and I'll balance braking bias with a prop valve and pad compound.
Weight:
I put the car on scales and was happy to find a neat weight balance. I didnt write the numbers down but it was basically perfect left to right and had about 1425lbs on the rear and 1225 on the front, making for something like a 56/44 weight balance. Combined with little brake dive and front lift on accel it was a really balanced car to drive on track.
Aero:
The front end has some serious downforce that ramps up over 50mph. I was able to take high speed corners with zero understeer even with the LSD doing its thing but at low speeds it would understeer pretty bad sometimes (I have a few fixes for this in shock adjustment and some alignment/tire issues I had, so mostly ignoring this for now). The rear felt planted and consistent which is nice but I would like to add a big wing soon so I can really balance it out at speeds over 70mph.
So you've switched from drag racing to road racing? Pretty cool. I've always thought the Fiero was more suited to road racing, anyway.
The front suspension looks to be the Held / Arraut coilover setup for the '88 Fiero. Just FYI, those steering knuckles are known to fail at the welds. I'm not trying to scare you, but maybe have the welds inspected for stress cracks.
Also, I would strongly suggest some ducting to cool the front brakes. It'll have a big impact on pad / rotor life, and will reduce brake fade. Those CTS-V calipers are a popular upgrade on heavier cars (like Camaros, for example). So they should do fine on your Fiero.
Edit to add: Looks like the CTS-V calipers require an 18" wheel.
[This message has been edited by Blacktree (edited 06-09-2020).]
A) Do you have original 88 Spindles or the Held spindles?
B)Rather than go to Gigantic brakes, make sure the originals are working properly with good pads, and definitely duct some cooling air to them.
I have an 85 SE V6 w/ 3.4 F-body- 5 spd-88 rear + brakes all around (Fronts are 12' discs on original 85 suspension)
I corner carve on back roads all the time; Usually going up-hill to not abuse the brakes, but since the conversion to 88 brakes I have been running it hard down hill- No fade of any sort....(I admit this treatment is not as harsh as track racing, but I do believe that some of the gigantic brakes on modern cars is overkill- and they require giant wheels which weigh more, killing performance of Brakes/engine/suspension....try to stay light but well-prepared!
I don't know about the CTS-V calipers but for the F-body metric caliper there's a plethora of pads compounds. I run Hawk DTC-30 front pads and you can literally run with the brake pedal depressed and it will not fade.
I don't know about the CTS-V calipers but for the F-body metric caliper there's a plethora of pads compounds. I run Hawk DTC-30 front pads and you can literally run with the brake pedal depressed and it will not fade.
Camaro calipers are what I want to run, but so far I haven't found an easy way to use them as the rotors will allegedly hit my knuckles and the calipers are not easy to adapt. I run DCT 30 60 and 70 in some combination on my S2000 and CRX, AND the price of the pads in the camaro caliper are almost half of the honda pad prices.... I'm going to keep looking at the camaro stuff and see if I can figure it out.
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A) Do you have original 88 Spindles or the Held spindles?
Held knuckles built with 88 brakes and 87 spindles. To the comment on their failure being common, all the research I have done says that the older knuckles were the ones that started having these issues and not so much for my early ones. I have looked around at these and while they were bent up a little bit I never found any cracks that worry me.
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B)Rather than go to Gigantic brakes, make sure the originals are working properly with good pads, and definitely duct some cooling air to them.
I'm the first to say this to everyone, but the reality is the 88 caliper has zero performance options out there for pads... and the rotors are not the right size for what I'm trying to do either. My s2000 is roughly the same weight as this fiero and the brakes on it are undersized, and the fiero makes more horsepower. the s2000 brakes are about 11inch rotors with a big caliper using the most extreme brake pad compounds available, so the overkill I'm planning isnt that wild to me.
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Edit to add: Looks like the CTS-V calipers require an 18" wheel.
I really hope that isnt the case, the goal is to run a 12inch rotor and use a ctsv caliper, but I am really planning on staying 17in wheel ready. the WCF kit claims that they are 16in wheel compatible. I may need to use a caliper that is like an acura TL brembo and not a CTSV if there is an issue with a 12in rotor. https://westcoastfiero.com/...kes-1984-1988-brembo
Yes this is Gingerman in South Haven Michigan. I will be heading to Autobahn raceway in Joliet at the end of the month, and would like to have the new brakes on by then.
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So you've switched from drag racing to road racing? Pretty cool. I've always thought the Fiero was more suited to road racing, anyway.
I've been on road racing for about 5 years now with my hondas, just now messing with the idea of a Fiero race car though. Drag racing on a budget was much easier on 20 year old me's wallet, now that I'm into my 30s with a mortgage free house and a nice garage I can spend the $3500+ a year in track fees along with expensive "must have" road racing parts like brakes, safety, and reliability mods. My s2000 doesnt have a full cage in it, so I've been working on retiring it from track duty using this fiero as the replacement for my "slow" driver training beater car to turn laps in. I will say even running bad this car loved to get out there and run a hard 20 minute session which is more than my hondas have done.
[This message has been edited by darkhorizon (edited 06-10-2020).]
I should have fully read your post at the beginning........
I have the 88 calipers up front with 12" C4 Vette rotors- they work very well and clear my 16" wheels (Would not clear 15")
Also, I have a 3.4 F-body long block under the stock L44 induction/controls-So 160 HP but 200 Lb/Ft)......2 years ago I was taking a shortcut on a Sunday and came upon some guys doing a clandestine Gymkhana in an industrial parking lot....Just cones. I watched for a bit and the head guy was driving an S2000- We talked and I stated I'd always wanted to try a cone course. He rode with me at first (Hard to know which side of which cone...) and then after a couple of laps he got out and I went at it for 3 laps....after the third lap he came up and told me I had beat his time......(He was an ex-Miata racer and was stepping up to the S2000...On a longer couse his S2000 would have been able to make use of it's superior HP)
I have done some odd things with the way my Stabilizer bars are mounted- improve both turn-in and cut back on DTO...and with 200 lb/ft of Torque, it is a monster from 0-30(Like in a cone course)(General G-max All-season tires...Don't know what tire the S2000 was running)
I'm interested to see why this car behaves so differently at high and low speeds. I have a small feeling its not an autocross setup as it is now, but I also need to grease the swaybars (forgot to do that, whoops).
What speed range are you talking about? I had a 73 mach 1 that rammed every bit of air below the hood into the engine compartment, where it had nowhere to go (Hood area is 3000 sq in so 1/10th PSI += 300 lbs of lift) So I made a custom airdam and then BLOCKED off the whole grill- the only air allowed in the engine compartment was Below the bumper- the width of the radiator. The car (Before) would float above 65 mph, but after I had it up to 95 mph and it was rock solid.
My 87-88 base car nose rams too much air in- I had my Fiero up to 90 and the headlight doors popped up....SO some venting plus blocking off a bit of intake would show improvements.....You want no lift, just enough air to cool the radiator/engine (Plus brakes)
The GT nose is better aerodynamically but not perfect....Possible use some lexan to cover the outer edges of your opening and then run it to see aero behavior (And watch for overheating)......(More and more air into closed space equals hotter...Better to get air OUT more than comes in so low pressure which equals colder air)
Goal is to run a 12:1 power to weight wheel to wheel class. From there maybe I'll start to do some unlimited horsepower stuff and chase lap times? Yet to be seen there.
The big car (Camaro/CTSV) Brembos will require 1.25" thick rotors, and are really designed for diameters in the 13"-14" range. Due to this the mounting ears are longer, and it may be tough to package them with a 12" rotor. The '88 Fiero and C4 Vette 12" rotors are 0.88" thick, so they will definitely not work. 4th gen F-body rotors are 12" and 1.25" thick.
For '88 Fiero calipers, the pads for Wilwood Dynalite calipers are really close. With a little grinding on the backing plate and drilling out the retention pin holes, they will fit the Fiero calipers. There are a lot of pad options for the Wilwoods
The P.O. of my '88 race car swore by them (and was running stock sized rotors). I intend to use them as well, especially since we are going "light" with Ecotec power, stripped chassis and staying with a 15" wheel (again, weight savings). Yes, good ducting to the brakes (and hubs) will increase life expectancy dramatically.
I love the Carbotech idea, but man for over $550 a set I'm a little hesitant although with a rotor upgrade these would work great. The dynalite option below is under $150 for pads, and any brembo I buy would be under $250 with effectively 3x more life expectancy of either the dynalite and carbotech options.... Its easy to spend money on them but I wouldnt be that happy about it.
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For '88 Fiero calipers, the pads for Wilwood Dynalite calipers are really close. With a little grinding on the backing plate and drilling out the retention pin holes, they will fit the Fiero calipers. There are a lot of pad options for the Wilwoods
This is very attractive if I can get the corvette 12 or Guru 13in rotors up front easily. The sad part is I will still want to buy a few calipers to have some spares and whatnot.... I just really hate the design of the 88 caliper and their availability.
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The big car (Camaro/CTSV) Brembos will require 1.25" thick rotors, and are really designed for diameters in the 13"-14" range. Due to this the mounting ears are longer, and it may be tough to package them with a 12" rotor. The '88 Fiero and C4 Vette 12" rotors are 0.88" thick, so they will definitely not work. 4th gen F-body rotors are 12" and 1.25" thick.
I'm not set on any specific set of calipers, I am sure I can find a set of reasonably price brembos that will fit, likely off the hondas as they use a 12in rotor on them with a 1in thickness. The C4 is probably about a 0.88 thickness which shouldnt be too hard to deal with..... $460 for the calipers here, and probably $150 for rotors and centric rings?
For a race car that can get by without a parking brake, you can use fronts on the rear.
Thanks, that is a slightly better price than I am seeing. I have had an 88 fiero with these 88 calipers for most of my life, and I cant remember a time all 8 of the slider pins worked correctly on any one of them.
Sadly I think with all this great info I am going to be bolting up stock calipers to 13 inch rotors come next week. Its a very simple, quick, and inexpensive solution to my brake problems, and I cant say its impossible to upgrade to better calipers when the time comes to replace pads.
Porterfield makes R4 and R4S pads for the '88 Fiero caliper.
This has been talked about alot, but I'm not willing to test/learn/experiment with these pads in a track situation. I really need to have alot of trust in my brakes and I put alot of value in being able to change the compounds front and rear more so than tuning the brake pressure bias. The hawk/carbotech/PFC pads are things running on 99.9% of the cars that I run with.
Looks the same to me, but they just cut away all the old spring stuff to save some weight. I confirmed today that the front bearings appear to be OEM 88 bearings.
All the Ryane/Held/Arraut drop spindles and spindles from their complete front end kit used 88 rear wheel bearings. Cutting away the upper spring perch and putting the upper spring mount where it is allows the use of a wider variety of shocks. The stock shock that came with their kits only give 4" of shock travel so unless you do a mod like that you will break shocks when they bottom out. Even the sport front end kit for the 84-87's has that problem.
------------------ 86 GT built 2.2 ecotec turbo rear SLA suspension QA1 coilovers on tube arms
There is a thread by DonP about their 88 Chump/Lemons car and they ran stock brakes and had no complaints about them. Endurance racers are admittedly not as hard on the brakes though.
------------------ 86 GT built 2.2 ecotec turbo rear SLA suspension QA1 coilovers on tube arms
Random update: Spent many hours today trying to figure out my hesitation/misfire. Its a really goofy issue that Ive had since I started it up on this new motor. It runs fine parked, its really jumpy driving it around, like when I touch the throttle sometimes it runs normal sometimes it stalls for a few seconds then lurches off. Then once it lurches it runs fine but severely lacks power until exactly 4000rpms, then it gains 150+hp for a second then quickly starts losing it... By about 5500rpms its not making enough power to accelerate anymore if its in 3rd gear. I raced all weekend with this problem so its not "super bad" because of how it works perfectly fine at 4000 rpm and tolerable up to 5000... but its really dumb having this powerband. I would say the beginning of the day the first day it ran fine but down on power from 2500-4000rpms, until eventually now its so bad it wont run there.
To fix it ive tried changing the tune wildly, 20% more fuel everywhere, 20% less fuel everywhere, basically wildly varied it rich and lean while still being able to drive, no change, although i think leaner is slightly better than richer.
I noticed the knock sensor is reading alot of activity at most any non idle event. I easily disabled it in the tune so its not changing timing, but it still runs the same.
For what its worth, this is a 94 motor with a cam sensor and a crank pulley sensor (which i removed). I am still using the 91-93 ECU in its stock form. I had to move the knock sensor from the old motor to this motor, and I really think I did an ok job of torquing it down to spec, but i understand this can be a bit tricky.
Also, the fuel system sat for awhile, like 8 years or something, without any significant care, which is the direction i'm heading tomorrow with a fuel pressure test. I had it in my head that it wasnt a fuel pressure issue before I went out to the shop today.
Is there any way for you to record and see live data?
Yes, I was logging all of these. I was able to observe the knock data and validate all of my pertinent sensors (TPS, MAP, RPM, VSS) this way. I was ready to put my wideband in as well but the wild extremes of AFR were clear on the oem narrowband. I am not tot he point of running well enough to need this.
Originally posted by darkhorizon: ...For what its worth, this is a 94 motor with a cam sensor and a crank pulley sensor (which i removed). I am still using the 91-93 ECU in its stock form. I had to move the knock sensor from the old motor to this motor, and I really think I did an ok job of torquing it down to spec, but i understand this can be a bit tricky...
I'm assuming you removed the crank pulley sensor because it is not required for the ECM you are using. I recall vaguely that some of these motors incorporated sequential fuel injection, which switched to batch fire after a certain rpm, although I never dealt directly with any code masks where that was in use. The consistant 4000 rpm change suggests to me that this is a switching point for something in the ECU. The closest thing I can relate to it involves a modern swap where a motor was cutting out at 4000 rpm. It turned out to be a rev limiter kicking in because during the swap, an associated sense wire was left disconnected causing the PCM to believe the motor was being revved in neutral.
I'm assuming you removed the crank pulley sensor because it is not required for the ECM you are using. I recall vaguely that some of these motors incorporated sequential fuel injection, which switched to batch fire after a certain rpm, although I never dealt directly with any code masks where that was in use. The consistant 4000 rpm change suggests to me that this is a switching point for something in the ECU. The closest thing I can relate to it involves a modern swap where a motor was cutting out at 4000 rpm. It turned out to be a rev limiter kicking in because during the swap, an associated sense wire was left disconnected causing the PCM to believe the motor was being revved in neutral.
This is using the old 1991 style ecu, which is just a single crank sensor. I am finding the opposite issue and that it has a rev limiter at 3000rpms, and runs fine once it gets to 4000, lol.
Have you checked cam timing? The PO may have done the 6* or even 13* cam advance mod for more top in. Driven one like this before and they're quite testy till 4k and above...
Have you checked cam timing? The PO may have done the 6* or even 13* cam advance mod for more top in. Driven one like this before and they're quite testy till 4k and above...
no, but it idles pretty good. I would also expect that it makes more power as the RPM go up as well, which it clearly doesnt. Its making less than 50hp by the time it makes it to 6000rpm.
Random update: Spent many hours today trying to figure out my hesitation/misfire. Its a really goofy issue that Ive had since I started it up on this new motor. It runs fine parked, its really jumpy driving it around, like when I touch the throttle sometimes it runs normal sometimes it stalls for a few seconds then lurches off. Then once it lurches it runs fine but severely lacks power until exactly 4000rpms, then it gains 150+hp for a second then quickly starts losing it... By about 5500rpms its not making enough power to accelerate anymore if its in 3rd gear. I raced all weekend with this problem so its not "super bad" because of how it works perfectly fine at 4000 rpm and tolerable up to 5000... but its really dumb having this powerband. I would say the beginning of the day the first day it ran fine but down on power from 2500-4000rpms, until eventually now its so bad it wont run there.
To fix it ive tried changing the tune wildly, 20% more fuel everywhere, 20% less fuel everywhere, basically wildly varied it rich and lean while still being able to drive, no change, although i think leaner is slightly better than richer.
I noticed the knock sensor is reading alot of activity at most any non idle event. I easily disabled it in the tune so its not changing timing, but it still runs the same.
For what its worth, this is a 94 motor with a cam sensor and a crank pulley sensor (which i removed). I am still using the 91-93 ECU in its stock form. I had to move the knock sensor from the old motor to this motor, and I really think I did an ok job of torquing it down to spec, but i understand this can be a bit tricky.
Also, the fuel system sat for awhile, like 8 years or something, without any significant care, which is the direction i'm heading tomorrow with a fuel pressure test. I had it in my head that it wasnt a fuel pressure issue before I went out to the shop today.
Do you have a big (~10ga) ground wire to the coil pack baseplate installed?
A Northstar missing that wire will *NEVER* run right... I @$$ume other GM DIS systems need to be similarly grounded. The Northstar needs the big wire because the coil pack mounts to the valve cover, which is rubber mounted--and thus electrically isolated--for noise reduction.
How well grounded is your coil pack? Do you have a phenolic intake spacer?
[This message has been edited by Will (edited 06-15-2020).]
Do you have a big (~10ga) ground wire to the coil pack baseplate installed?
A Northstar missing that wire will *NEVER* run right... I @$$ume other GM DIS systems need to be similarly grounded. The Northstar needs the big wire because the coil pack mounts to the valve cover, which is rubber mounted--and thus electrically isolated--for noise reduction.
How well grounded is your coil pack? Do you have a phenolic intake spacer?
I dont think there is much grounding the base of the coil pack, its basically ziptied randomly to some hunk of scrap aluminum. I'll ground it better asap.
Will, I made a much better bracket and tested that with some slightly better results of spark, it feels like it ran much better on a quick test drive. I also grabbed a spare set of coils and IGN module.
Fuel problem was found last night, likely the source of all my engine related problems... I cleaned the aftermarket fuel filter out and found a ton of junk which prompted the fuel tank drop. I knew I should have done this from the start but I tend to be overly lazy until stuff starts to really line up as the problem. 100% of the 3800 stuff I've done with fieros would shown absolutely no chance of even running at all if I found this in the tank. Pretty amazed to be honest.
"fuel pump jacket" melted onto the fuel sock, which also turned to goo.
