Stock Integra Rebuild (Dyno run before and after)-coming soon*

cpeehler7

Banned
Hey everyone, been a while since I've stopped by the forums here. Just wanted to let you guys know about a fun little project I've been working on lately. Most of you probably don't remember who I am, but I autocross my Integra in Street Touring class, so the motor is stock, aside from the exhaust. The issue is, that the motor was burning a whole lot of oil...ran great, but especially in Vtec it was guzzling oil haha. So I decided to do a total stock motor rebuild. The cool thing is, my co-driver has a dyno and wanted to see how much power was lost over the last 16 years and 163,000 miles. So we tossed it on the dyno before, and we'll toss it back on the dyno tonight after we drop the motor back into the car. The only difference is going to be the fact that we removed the A/C compressor, that is the only difference there will be to the car from the before and after.

I figured some of you guys here might be interested to see exactly how much or little power high mileage could be taking away from your cars. Usually when people rebuild they go nuts and build the motor, but that isn't allowed for my race class, so everything is stock replacement. Should be interesting to see, after we get the later dyno results, we're going to toss an air intake and a high flow cat on the car. Just didn't want to do those upgrades before we do the after pass on the dyno, that would really screw up the results haha.

Anyway, I should have pics up tomorrow, finishing the project tonight. Unfortunately I haven't gotten any new pictures of my integra this season of autocross since the motor was out last race. I did take my buddy's miata out for a spin, and had a blast. Probably going to buy it next year lol, and since a thread is useless without pictures I'll just toss one of those up for the hell of it. I'll get some of the integra soon, should have it out racing in a couple weeks. Also will get pics of the before and after dyno graphs, should be interesting to see

 
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cpeehler7

Banned
Alright everyone, so the results are in, a little later than expected due to being busy. The results are pretty interesting, and I'm definitely satisfied with the results. Unfortunately the humidity was not constant between the Pre-reuild and post rebuild runs. It was about 55F and 73% humidity for the pre-rebuild runs. And 65F and 78% humidity for the post rebuild runs.

Now to make this clear, the integra I was running is a Stock motor 1998 GSR with an OBX header going into a Yonaka Catback exhaust (stock cat is still in place). That stays the same for each run but the last one, which we added an old iceman cold air intake with a ragged looking filter on it.

I have 4 total passes:

1: Pre-rebuild w/ exhaust

2: Post-rebuild w/exhaust (no graph for this run was nearly the same as #3 minus 1whp 1wtq throughout)

3: Post-rebuild w/exhaust and timing adjustment

4: Post-rebuild w/exhaust timing adjustment, and cold air intake.

So I'll cut straight to it and start putting the graphs up, you'll have to do a little reading I have the printouts not the actual file, so I couldn't get the peak torque and peak HP to appear on the same printout. So I just picked the peak torque, and the peak HP is printed at the bottom right in dull teal print. Not the greatest, but that's what we have to work with...

#1 Pre-Rebuild:

The motor was blowing some serious oil, the intake manifold was real clogged up with oil even. The valves were pretty nasty, definitely not closing all the way.

#2 Post Rebuild:

So the peak HP went from 165.9 to 171.9 and peak torque went from roughly122 to 126.7. The motor was quite a bit more responsive and you could definitely feel a little extra power. Nothing crazy obviously, but the motor was clearly healthier and running stronger. Also not smelling burning oil when WOT is a huge bonus!

#3 Post Rebuild w/ Cold air intake

Now this is where you, if you're anything like me, will say what the hell? We genuinely expected like 3-5whp from the air intake... And were completely shocked when we netted about 11whp and 6-8wtq. Right around 3000rpm the motor was about the same as the post rebuild with the stock airbox (Fram filter). After that you could see significant gains surprisingly. About 11 peak whp and ~6wtq. There weren't really any serious dips in the graph with the cold air intake either. I sort of expected it to just shift the power toward to top end a little bit, but basically everything after 3000rpm was improved with the cold air intake.

Granted the cold air intake was in direct air from the fan, and the stock air filter was probably heat soaked in the box. But I don't think that makes up for over 10 wheel. Hopefully you guys enjoyed this, it was a great time learning how to rebuild the motor in my car. And even more fun seeing exactly how much power was lost over 163500 miles, and even more exciting to see power gains from an air intake that was just tossed in a box in the garage hahah. Hopefully you guys enjoy this thread, I'm getting pretty amped up to finish the suspension work for the rest of the autocross season. I think the car is going to be great this year, despite it being a non-competitive car. I think superior driving skills in a "lesser" car will bring good results!

Also, here's the picture of the car on the dyno (picture was taken while my co-driver was grabbing the intake. No we did no run the car with no intake.



**Also could someone change the title where it says ***Coming Soon*** Thank you! Enjoy.
 
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Aussie

Zoom-Zoom
hp = (tq x rpm) / 5252

Nice work with the rebuilt, good to see it's pulling higher numbers.
 


Samurai_Blue

Yolo Whippin'
hmm those are some healthy numbers. I make 177whp on the Raceline USA dyno which is used by some after market manufacturers and Super Street.
 

cpeehler7

Banned
Lol good to know, pardon my ignorance.

All I really have left to do is put a new header on (2.5") leading into a high flow cat. For the street touring autocross rules that is all I can do for power at this point. The only thing I was worried about with the motor was the fact that we couldn't put oversized pistons in per class rules (even though no one would see them or care). And my cylinders were pretty oval'd out. The piston to wall clearances were a couple thousandths too large on cyl 2-3. 1-4 were dead on. So far doesn't seem like any oil is slipping by, signs of burning like before :roll:

I'm looking forward to fixing the rear end now. Trailing arm bushings are shot, and something is a little messed up with my rear swaybar endlinks or bushings. Either the bushings went, or the endlinks were bent because it feels like I don't have any rear bar on my car. Even odd jabs at the brake mid turn doesn't kick the back end out. Before that would have spun it instantly. I just need to get the liftoff oversteer back and we'll be in business. That and I should order a set of the new bridgestone RE71Rs. Those things are doing quite a bit better than the ZIIs nationally, I guess that's this years winning rubber.
 
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