I agree. Somethings not quite right. Although pretty, I think the intake manifold and possibly the injector placement is killing power output. Going back to the traditional IDA style intake would most likely net a better result. For example, a 13b pp made 300rwhp at 10500rpm. Torque was 150ft/lb @ 10500rpm, and peaked at 187ft/lb @ 8000rpm. Timing was about 26deg. In my experience timing is dictated more by the compression ratio/combustion chamber depth, than anything else, although VE definitely has a bearing.

I'd be surprised if upgrading the ignition makes much more power. If at all possible do a back to back test on the dyno. Let us know how you get on.

 

Well, I think I might have found part of the problem. Friday night I noticed that two of the nuts on the lower part of the manifold were never tightened. I was in a hurry getting everthing together. The rest of the bolts were tight, but I have to believe it wasn't good to have those other two nuts just hand tightened.

Everything is tight now, and we're working on the ignition. Hopefully it helps.

 

any updates?

 

Just got back from Cal speedway, we had problems though. We had put some coils on that were built for drag racing, power was good for a lap or two, then would start falling off and wouldn't want to rev. We're pretty sure that was the problem, still need to go to the dyno. I have a feeling that the intake might be a little to crazy for my porting.

 

Another thing I was thinking, I have a feeling that my dry sump combined with 10.5" wide slicks are probably robbing at least 10hp at the wheels. what do you guys think? The dry sump pressure is set at just over 100psi and holds a total of 12qts between the tank/and 2 fat oil coolers. redline 20-50w oil. I'm pretty sure I would pick up horse if I had a normal wet sump and 205 wide street tires. This obviously is not would I would run for road racing though. Just food for thought.

 

IMO you should go back to the intake you had before. seems that it would work better that you new one. but is just my opinion. you ever try to swich intakes on practice runs to see any difference?

eddie

 

What are the ID's and lengths of you intake? It looks like you may have low velocity in the intake that is killing your torque. That power curve still climbing shows you have plenty on the top.

If they are limiting your rwhp in the class, bring the power lower and make a fast tractor out of it with more torque.

And yes, the slicks will suck power on the rollers compared to street tires. I don't think the dry sump is hurting power any more than a stock pump at the same pressure. It may be better if the pump is a better design.

 

It takes to long to swap intakes at the track. Different TPS', and fuel injectors, throttle linkages, etc. We could do it, but I'd rather not do it at the track. I will be able to tell which setup is faster, I just need a weekend without problems.

 

I run at Buttonwillow next month, I ran a 1:54.7 last year with the old intake, we'll see what I run this time. I still need to change the ignition coils to non-drag race coils.

 

you could do lighter oil and drop the PSI a little, but why? if you're not going to run it at the track like that, it doesn't matter...

our (piston) engine guy is a drag racer and they run like 0 wt oil at stock pressure. um... they get away with it, but you know their whole season is shorter than one session road racing, AND they expect to rebuild the thing at least once....

 

We still have Pennzoil 70-weight in stock!

Back inna old days, you opened the clearances up a lot so the whippy cast crank in the floppy slightly-lighter-than-it-really-should-be cheese iron block wouldn't hit the bearings too much. Then you ran high oil pressure to try to stabilize things, and super thick oil so it didn't just fall right out of the first bearing journal it came across.

0w oils are permissible because of strong cranks and stronger blocks that allow sub-.001" bearing clearances.

 

you're basically right, but its still not a good idea to go roadracing like that. our honda engines basically don't last the whole 25 hour race as is, and that's with thicker oil, oil cooler, and an accusump.

we actually calculated this out, the entire battle of the imports (or whatever) drag racing season is under 15 minutes of run time, our road race season is like 20something hours. its a huge difference

 

That's why I don't really want to try lighter oils. Right now I'm trying to concentrate on getting the oil temp down anyway. I have a bitchin' oil system with two oil coolers, but I have bad duct work leading to them. I saw almost 240* temps at the end of a 30min race, meanwhile my water temp was only 160*. Not good!

 

so how is the racecar running latelly?

 

also interested in the new result with the ignition and maybe intake mod?

As for torque you should be netting some more, I get 132 ft-lb with 12A SP that's been run for 2 years now, running stock seals, nothing balanced or lightened on the inside.

 

The ignition didn't have much effect. It seems like the stock second gen coils with one MSD digital 6 box was enough. It turns out that I had a fuel pump going out causing the motor to run lean and lose HP. We have that fixed now.

We just put the old intake back on with one exception, we had a machine shop cut almost 2" from the top of the lower intake manifold, and welded it back up. We had to do some grinding on the inside of the ports afterwords to smooth it out slightly. Hopefully we'll get it back on the dyno soon. We use to make around 232whp @ 8000rpm and 165ft/lbs, that is SAE corrected dynojet results. With the short intake we made 240whp @ 9500rpm and 140-142ft/lbs.

I'm hoping to make 235whp @ 8500rpm and 160-165ft/lbs of torque with the old intake shortened. I should have dyno results next week.

In the meantime we've been working on suspension and trying to get the car lower. We clearanced the inside fender wells, and cut 3/4" from the bump stops. I also am modifying the bump steer adjustment kit that Mazdatrix sells for the FC and adapting it to my car. I put another inch of turn in spacers below the struts and purchased the ackerman arms that sevensonly sells. I'm hoping to optimize my suspension geometry in the front soon. We are also relocating the 3rd link (trilink) from underneath the car to inside the car.

Getting prepared for nationals in September!

 

its hard to get a lot of torque out of something that has a 1.1" stroke (if talking piston banter)

 

wrong.

Torque is function of BMEP and displacement. Nothing more, nothing less.

 

My torque was great before, I was planning on losing some torque with the modified intake, but not that much. I also expected to gain more than 8hp. My porting is to small for the intake. When we tear this motor apart in the future we will turn it into a J or D Bridge, then we'll try the intake again.

My porting is small, even for a non J bridge. My intermediate housing port still has the peanut shaped port, it's got the bridge, but much smaller than the ports on the end housings.

 

actually were both right