Well I had the car dynoed today and I'm very disappointed in the results. Last year I dynoed at 199HP with stock fuel pressure, stock plenum, and everything else pretty much as is. Today with the ported plenum, fuel pressure set at 48PSI, new MSD coil and wires I dynoed at 197HP. The torque stayed the same at 292.

There is quite a number of factors...One, the fuel pressure might be too high. I've got another dyno session booked in a couple weeks, so I can play with the pressure then. I think optimal for my car might be in the range of 45PSI perhaps. And the weather was extremely damp today compared to the last time I dynoed. But still, I can help but think that I wasted all that time and money over the winter only to see no gains. I would have been happy with even minimal gains, but a lose?!?

Anyway, I'm just ranting right now, perhaps I need to relax and have a beer....cause I'm actually considering giving up, throwing in the towel and buying a fourth gen instead. I'm very discouraged to say the least as I don't get why my car isn't responding to any of the mods.

 

Hang in there guy. From what I've been finding out, you're probably right, the fuel pressure should be 45 - 46 psi.
They're running 48 - 50 psi. in 11 & 12 sec. cars with nos.
Think you'll find an improvment.
Good luck.

 

Thanks for the encouragement...I really hope that's right.

 

I would be interested in the dyno numbers under the curve, at say 2500-3850 rpm, this year over last year. The reason I inquire is the mods you mention would effect hp and torque at mid-rpms rather than peak-rpms. It sounds like you are focusing on peak ?

For instance if I installed a new AFPR I would hope to see my torque improve beginning somewhere around 2200rpms and expecting the gains to flatten out by about 4250pms. (By-the-way 292lbs torque equates to 350.4 lbs torque using the standard 1.2 driveline ratio -- that is ALOT of torque). I have a question -- does the AFPR have to be used with a custom chip that understands what to do with the increased fuel pressure ?

I have to say I wouldn't expect any meaningful gains from an MSD upgrade. Sorry for the bad news. I know, I've done the MSD thing before and quite frankly was underwhelmed by what I received for my $$$ spent. I am not a believer when it comes to MSD, Accel or Crane ignition systems -- seen too many people buy them and get marginal increases in performance as a result.

IMHO, if you want real performance increases from an ignition system upgrade then I suggest you look to Jacobs Electronics. I just recently purchased a Jacobs Ultra Team for my Formula. I expect about 10-12hp gain and about 22-25lbs torque gain from this package. I've installed this package previously on a 3rd gen and didn't waste anytime buying one for my current 3rd gen. Oh yeah, they guarantee the increase in hp and torque or your money back (won't get that from MSD, Crane or Accel). I am still waiting for it to arrive in the mail but expect to have it installed before the GB weekend so I can show it to you then if you are interested.

thx,
RP.

 

Palric: I agree with basically everything you said. I do concentrate on the peaks, yes, but I know that the rest of the curve is equally important too. I have to dig up my last dyno sheet and do a direct comparison, but from my memory the one from today is very similiar.

The torque, although I would like to see it break the 300 mark, I am very happy with. What I don't like is the very unequal balance of the HP. I would really like to know why it's so low in comparison to the TQ values.

From my understanding with the AFPR, and any other mods, a MAF car is supposed to be fairly good at understanding and relearning compared to a speed density car. I could be wrong here that's just what I've gathered from my reading. I was beginning to wonder myself if I need a custom chip at this point as my car is not responding very well to change (obviously). I do have a ADS Superchip sitting here (got it off eBay for only $30), but I want to dyno again and try to optimize the fuel pres first before installing a chip.

As far as the MSD stuff goes, I really wasn't expecting any gain out of those anyway...especially just wires and a coil. I would expect a very small gain with the 6A installed, but it's still sitting on my table. I would be very interested in hearing your results from the Jacobs Ultra Team (I'm sure you would post them up here anyways). Do you plan on dynoing your car first before the install? Before and after numbers would be very useful. If you did post gains of 10-12HP, than I would gladly switch over to Jacobs as well.

 

"cause I'm actually considering giving up, throwing in the towel and buying a fourth gen instead. I'm very discouraged to say the least as I don't get why my car isn't responding to any of the mods."

Hey IROCKER you don't want to do that, Any Moron can buy a fast car,it takes skill,work and elbow grease to build one. It seem's to me you are on your way to an awesome car and when you get done(like were ever done)It will be "your" car built "your" way. And no matter how much money someone is willing to spend there won't be another one like it. You can't buy that feeling. SR

 

P.S I love those flames..........SR

 

Thanks snowracer for the encouragement and the compliment on the flames...It's real frustrating though when I watch my friends with the 4th gens pulling 270-325HP (LT1/LS1) with similiar mods to me. *sigh* I would love nothing more than to stroke my L98 to a 383 but I won't have that kinda coin for a while.

 

Are you discoureged because you see the numbers as low or is it because you expected more power from the mods you did?

 

If it makes you feel better i will dyno my car and we can compare give me a call sunday and if you sell that iroc i will come round and kick your ***. like you told me "you will regret selling it"

 

Hey IROCKER... sorry to hear about the results at the dyno... but like you said, you have to find optimal fule pressure and ignition timing. You have a lot more room for timing adjustment.. cause you can richen the fuel mixture to compensate for detonation.

I was talking to my buddy Bill, and he brings up a good point about the MSD 6A box... this box improves spark energy and precision at high rpm's, but our engine doesn't see high rpm's.... so this mod may also be a waste of time, but I could be wrong.

The MSD coil and stuff isn't a waste in my view... My car ran much better with it, nothing like a hotter spark than factory.

The chip may also be your downfall, like mentioned in the other replies... By the "seat of the pants" dyno, my car seems like it got gobs more torque, maybe a bit of horsepower. I wish I could have went to the dyno day to see what I am getting for power... oh well, another time. Maybe we can compare settings, and see what works best.

 

hay palric the o2 will compinsate some what for the AFPR. if its running rich it will just reduce the duty cycle on the injectors.


Irocker you realy dont want to sell do you? i think every thing palric said is right on. but you may want to check out the price of the jacobs sys first. from what i hear its pricey. there are other things to make your car faster for less

 

I think you could unlock alot of HP and thereby balance the engine by installing a set of headers. Speaking of my last f-body, of all the mods that I did installing headers had the most noticeable effect in power and daily driving characteristics. (keep in mind I had a very well tuned exhaust system attached to the headers). Also, every mod that I did after the headers was magnified in effect because of the headers.

I still have more questions than answers about the AFPR. What does it do to increase torque and hp ? I read a page under tech-notes that talked about huge hp and torque increases using an AFPR and it all sounded right off the wall to me. I have to do more reading on this because I don't see how you can add more fuel (more power) and keep the O2 sensor fooled ??? Wouldn't the ECM then try to negatively compensate for the extra fuel under the curve ? This stuff baffles me.

If you have a 6a lying around I think you should try installing it. These pieces are designed to work as an integrated system and even though I have minimal respect for MSD I would still recommend installing it -- chances are you will see a tenth off the 1/4 ?

Assuming my Jacobs arrives before the GB weekend (it is coming by ground mail 6-8 weeks -- I thought I would beat the border brokers that way) I will be glad to show it to you. Testing it is easy -- if you leave the factory coil in place you can simply install the Jacobs package then disconnect it for baseline times, then re-connect it to see the improvements in either the 1/4 or the dyno. I think I would prefer to test the dyno because 1/4 times are too variable -- given my driving.

BTW: you will probably find it very hard to sell your IROC. Not for shortage of buyers, but because you wouldn't be able to let go of it.

thx,
RP.

 

Hang in there.Thats the fun of it doing little tweeks and twisting of wrenches.Don't get discouraged,have another beer.

 

Hi again.
Not sure if this would be helpfull or if you're read it, but there is an article at.....
http://www.thirdgen.org/newdesign/te...ning.shtml....
It sounds like it would be interesting to try at a dyno session.

 

my computer skills are lacking...loll.
http: doesn't come up. Need to type it in.

 

Irocker, all I have gotta say is what every you do, DO NOT, sell that ride! Dont worry about your initial numbers, sound like you just might have something which is a little off (fuel pressure, etc), its just the begining of the summer and there is lots of time to work on things, so dont sweat it!

Like someone else said it takes a lot of time, cash and elbow grease to build a fast ride, hey it could be worse and you could be driving a crappy 305, L03 like me!!! Ha ha, actually its not that bad, it still runs strong for what it is!

 

Hey Nathan, after reading my comments I realize I was unfairly critical about MSD and indirectly those who use their products. I apologize for this, I probably insulted a few people (re: for using MSD, Accel, etc) and did not mean to.

My history is... I've had some very negative experiences with MSD and Accel, spent alot of $$$ and time with things that either did not work or worked marginally. That is not the fault of MSD or Accel, rather I just had not found the package that worked best for me until I tried Jacobs. FYI: the solution did not come cheap -- it is over $800 CDN for the Ultra Team (so it better work eh ?).

thx,
RP.

 

There was no offense taken here

And thats quite pricey for an ignition system, I'd sure hope it works too.. LOL.

I think with MSD, it will probably help you when you need a hotter spark, which we really don't need right now, cause we have stock internals in our engine. Thats my theory... All I know, is that it doesn't miss or anything witht he MSD system.. And, for the money I had to spend, I like the look of MSD better

 

I wanna start off by saying thank you very much from everyone for the kind and positive words. I could not ask for better support from a better group of people.

Acceld: I'm not discouraged so much by the low numbers (let's say compared to an LS1...as it really is an unfair comparison) I guess I'm disappointed by the lack of response from my car to the mods that I did compared to last years numbers. I didn't expect huge gains, as I know better than that, but to lose HP?!? That's where my disappointment came in.

Nathan: Email me about the dyno stuff if you want to do yours...as I will be running it again and already have a date reserved.

trigger: If you have ideas for mods that don't cost an arm and a leg than feel free to suggest. I'm always open to suggestions.

palric: I 100% agree with the headers idea. Unfortunately it's not in the budget for this year as I need all my money to buy a house this summer. Plus, I want the SLP's...I think it's worth holding off and saving some extra coin for those. And as far as the MSD 6A is concerned...it probably won't happen till late in the summer or next year. I really want to try it out now, but I just installed Rapidfire plugs last year and from what MSDtech told me that don't recommend those plugs with the 6A box. He said to switch back to regular AC Delco's before installing the 6A...We all know how fun plug changes are on the TPIs so I think I'll hold off a bit.

skidoo: Amen to that!

16th: I read the article but I'm not 100% sure I understand how to adjust the voltage...I'm not very electrically inclined. I have Craig Moates scanning software so I guess I really should hook that up and do some logging over the next week.

 

Well, at least one good thing came out of Saturday's meet...a good third gen showing! Check it out...

 

aww man!...I did not know that you guys were getting together this weekend? Is this a common thing? Where do you guys meet?
Chris, I am the guy who e-mailed you before about the OCC and your views about it...white 89 IROC...5.7L stock...
Is that Karsten's car on the far right?? I see that he has it back out on the road today...

 

Hey man...I hope my opinion on the OCC was helpful.

No, the pic isn't a regular meeting. I was at a TFbM meet at Agostino Racing on Saturday and a bunch of 3rd Gen owners showed up. I was pleasantly surprised! The owner on the end wasn't Karten, unfortunately I can't remember his name, but he's a new member.

 

Hey IROCKER.... Do you know what your car made at the wheels stock? Isn't the estimated powertrain loss 30%, or is it less?

 

Man I always loved those yellow IROCs. First IROC I ever saw was in an incredible bright yellow. It was on Georgia Street in downtown Vancouver back in '85. That was along time ago. Great to see one again.

What is the story on this car ? 5-speed ? 350 ? Will it be at the GB weekend ?

RP.

 

Nathan: At the flywheel it's rated at 230HP (according to the GM vintage services package I got) and normally you minus around 20% drivetrain loss. 30% is a little high.

Palric: That car belongs to an older gentleman by the name of John (probably in his 50's) and he's from the Woodstock area I think. It's a 305 LG4 with an HO cam and HO intake, and 5 speed tranny. It's also been lower and has the black honeycomb GTA rims. It dynoed at 194HP I believe on Saturday and I think his best time at the track is a high 14. Pretty impressive for an LG4 if you ask me!

 

ahhh.... so you have around 236 at the flywheel then... which is not far from factory specs... and you've done the AFPR, plenum porting, injector cleaning and flowmatch, MSD coil, wires.... anything else performance wise? Exhaust?

 

Have you got your chip in? If so did you see a diff
I just picked one up for $40 to day

 

No, haven't put in the chip yet. I'm waiting till I figure out this FP thing. What chip did you get?

 

i got the ads chip. i am going to try it (i dont expect much). if it sucks then i think it will be time for a custom burned chip.

right now i am still messing with the AFPG also. how are you setting it.
when the pump runs to prime the sys.?
at idle?
or under load

i set mine at 45psi at idle and it seems to be running VERY rich. i have a raw gas smell.( i thought that i had a fuel leak)

 

lol.. mine still may be running rich.. my buddy said my car stinks when I floor it.. but the car is running sooooo good... well, minus a miss at part throttle hopefully it'll go away while i drive it a bit more

 

i was just going back and reading old post about AFPR i did not set it right for sure . i did not know i had to remove the vacume line first i am WAY to rich.

 

hehehe

 

I've got the ADS chip as well. If you try it before me then definately post the results, whether good or bad. I'm not expecting much either but I figure it's worth a try. And if it doesn't work, then I'll be seeking a custom PROM as well.

 

I hope to meet up with him at GB weekend. I was looking for a yellow '85 IROC hardtop 5-speed when I found my '91 Formula and got side-tracked....

RP.

 

For some reason I don't see him being at GB, but you never know.

 

I was trying to find out if he has plans on selling his IROC anytime soon ?

RP.

 

Ahhh...Not that I know of. I think he's pretty happy with it...I would be with the numbers he's pulling off.

 

Well- now that I can get on the f'n board here:


Your 197hp may not be as bad as you are thinking if you had 199hp previously- Saturday at Agostino was extremely humid (it rained almost the whole time)- which I think would tend to cut down the on the fuel density getting to the engine. That being said, you may actually be higher than 197hp- if you could compare your car back-back before and after mods you'd get a much better picture on improvements in future.

Unfortunately, this still doesn't change the fact that quite a number of 4th Gens were running 290-310hp under the same conditions.

Next time there's a club 'dyno day' maybe I'll bring along the bigblock and dump out more than all the 4th Gens. just to be funny...

 

Thanks Eric. I agree that it was quite humid/damp and I'm hoping that was one of my factors. Different cars respond to different situations and I guess the L98 didn't like the moisture...possibly the LS1's did. It seemed that some of the LT1's were down in power too. My next dyno session will tell I guess.

And yes, the big block should have some impressive torque numbers!