208fabrication

Thanks. I will look into that. I went on a killing spree the other weekend and broke 3 axles in one day, all in the area you talked about. I talked to a local company https://dutchmanaxles.com/ about making some axle center sections out of 300M material and having consistent diameter throughout. They should be done early next week and cost ~$650 for a pair.

Newaza

Dang dude!! 3 axles in a day? that's hardcore LOL... You must have been launching with all the beans! Pos cat for being a stone cold axle killer!! But being a stick shift is much harder on those parts than an auto.
Hope those axle centers work out. The only issue I would think would be the 26 spline outboard part that goes into the hub. Although I havent broken that part of the axle, I think Pat did before. That is an advantage of doing the rx7 or 929 axles since they are larger 28 spline. Problem is the extra cost of getting broached hubs or using rx7 hubs and turning down for miata spindles. Those 929 axles are gnarly, the problem with them is you have to getting custom adapters made.

Newaza

Also just to update.

I made it out to my test spot to measure 40-80 with the dragy and the exhintake cam and preturbo vanes.
Unfortunately it is a tad slower, Well its slower to spool that is. Once fully in boost it seems to be similar to before.

I'm not sure if it is the cam swap or vanes since I didn't test individually. Since the vanes are the easiest to remove I'll retest without and hopefully get response and transient acceleration back. When I do 40-80 testing with the dragy I dont use the spool shot system, I just let it build boost naturally.

If still more laggy without the vanes I'll try testing with cam both advanced and retarded a few degrees before I swap back to original cam.

Newaza

Welp fellers it wasnt the vanes... I just retested without the vanes. Gotta be the exhintake cam swap deal. Im going to make an offset bushing for the dowel to allow me to advance or retard the cam a few degrees.. I strongly think it will need to be advanced slightly.. If doing that helps to at least match stock cam acceleration (hope to better that though) I will retest with vanes.

Newaza

So I made an offset bushing out of a scrap piece of brass stock on the lathe. The bushing allowed me to move the cam dowel of the exhintake cam about .025 of an inch which correlates to roughly 5 degrees of cam rotation. I installed to advance the cam over the original position I had the exhintake cam dowel located. Doing this got the transition boost response to be a match for the stock cam, but lost power up top according to dragy data. the best location would likely be to advance a degree or two over the original position I had the exhintake cam located. However I dont think it will be as good for overall acceleration as the stock cam on my particular combination in any cam position and I didnt want to waste any more time making more offset bushings to try cam in different positions, so I put stock cam back in. Maybe on other combinations the exhintake swap deal will offer measureable acceleration gains, but for my particular combination that proved to not be the case.

I will be re-installing the preturbo vanes and testing this week to see if that will offer any measurable gains.

Newaza

Update!!

Well guys I did a thing LOL.... I cobbled a quick test to see results of shooting air into intake rather than exhaust manifold. The initial results are pretty interesting.

I have to give Pat credit for pushing me to test this. We have had various conversations about the spool shot system and he has been a big proponent of trying the intake side. To be honest I wasnt convinced it would work very well on the intake side but Pat is a really sharp dude and he felt strongly it would work. So being that I have everything already in place I figured what the heck. I just needed to put a fitting in a spare piece of intake pipe I had and route the air hose to it.

Below is what I quickly and crudely cobbled together just for a one time test.




I was initially very concerned with shooting high pressure air into the intake. My thoughts were that the manifold pressures may spike very high before the wastegate could balance pressures to what I would normally expect. There is an increase in intake pressure over what I had it set for, but nothing to the degree I was concerned about. really just 4 pounds or so. That was with ~110 psi starting tank pressures shooting into 1/4" npt nipple threaded into intake pipe and aimed at throttle.

When I took out for initial testing I pulled 6 degrees of timing at anything in boost and set boost cut at 356kpa, just in case!!!

The first test round looks promising. It does not work quite as well as shooting into exhaust manifold in so far as boost rise time. Also shooting into intake seems to require some degree of positive manifold pressure for it to work well, doesn't take a lot, maybe 6ish or so psi, but it does seem to want some positive pressure and air flow prior to firing solenoid. Whereas firing into exhaust you can do at 0 boost and still get good results, but even firing into exhaust works better with some level of boost and turbine speed prior to firing solenoid. The more initial turbine speed the better the results.

The best comparison of data I could quickly find of boost rise times exemplifying the difference of shooting into exhaust vs best result of shooting into intake from today's testing follows::

Best test today was firing solenoid into intake manifold at 4662 rpm and beginning boost of 6.4 psi it took 1.067 seconds to reach 30 psi.

In the last tack outing of which I captured the dragy video of car running a 6.52 on timeslip at track (dragy showed 6.54) I logged the following boost rise data.
Launching at 3643 rpm at 6.4 psi it took 1.001 seconds to reach 30.6 psi. If I left at 4660 rpm and 6.4 psi it would have been roughly 1 to 2 tenths quicker to reach 30.6 psi, So figure 8 to 9 tenths of a second firing into exhaust if comparing apples to apples with today's test. So initial testing indicates firing into exhaust does yield better results than firing into intake in so far as spool time goes.

But not so fast cowboy you say??? What happens if we fire both into the intake and exhaust at the same time?? Could that be super gnarly?? Well we are about to find out LOL.... Although I took off the contraption I cobbled together earlier and reconfigured car back to firing into exhaust as it was before, I went ahead and ordered another solenoid to redo the intake side in a better fashion to function independently and/or in conjunction with exhaust side, So I will be able to fire both at same time or either one independent of the other. My hope is to get full boost in say maybe 60 to 70 percent of the time it takes now. If that pans out my 60' time should immediately drop by maybe as much as a tenth. That alone should get me into the high 6.30s.

One thing I didnt test today and something Pat was strongly suggesting is firing into intake at top end of track to pick up top end. The thought is since some of the intake air is supplied by the tanks is that air will be cold. The turbo will be working less and in a better part of the map so that will not add quite as much heat, so in theory it may allow for slightly more power due to cooler intake air and turbo doing less work.

I have an additional take though. If firing these together does spool as madly as I'm hoping I may up my turbo size or at least go up to the next a/r exhaust housing, which should add to the power pie as well.. Stay tuned fellers.

Newaza

So I quickly added another solenoid to the tank setup I was using and simply wired the solenoids together to fire at same time for initial testing. The larger solenoid is the one originally for firing into exhaust manifold. It is 3/4" npt with a 20mm orifice. The smaller one for going into intake pipe is 1/2" npt with a 16mm orifice. The tank is simply a 30lb steel propane tank.

Below is the contraption that gets mounted into trunk.


I tested to be in the worst possible conditions in so far as spool up goes. Current turbo is gtx 3576 .82 a/r. I used third gear which is 1:1 on my transmission from a slow speed of roughly 2900-3000 rpm when going full throttle with very little turbine speed at point of full throttle. Starting boost at point of full throttle was maybe 1 psi + or - a slight amount and measured to approximately 30ish psi on tests. So the timed measurement conditions as close as I could reasonably get were from 3000ish rpm, 1ish to 30ish psi in 3rd gear with around 140-150 psi starting tank pressures. With exhaust only it took 1.464 seconds. Firing into both it took a best of 1.201 seconds, so 2 tenths of a second or slightly better under these test conditions. The next thing I think I want to test is to control the solenoids separately rather than wire together.

The real test will be at the track where I can more properly test The "dual shot" capabilities. Last time at track it took 1.001 seconds to reach 30ish psi at transbrake release and launch from 6.4 psi and 3600ish rpm. I'm hopeful that the dual shot will allow me to get that down to maybe 8 tenths of a second under same conditions.

I quess we will see, but it did show a slight improvement on initial testing today, which makes me want to develop and push this a little further. Will be testing with more tank pressure and separate solenoid control soon. I may even add a second tank down the road to have two independent systems if it shows merit. I am hoping that I can get this working well enough to go up in turbo size or at least next turbine housing size.

shuiend

iTrader: (24)

One of these days I need to make the drive down to the strip to watch you run it.

Newaza

Hey fellows just a quick update. Also want to give a huge thanks to all the veterans out there!

So I went ahead and rewired the solenoids to where I can control them separately and independently of each other. I took out yesterday to run some more testing. It seems that firing them together does offer a small improvement over just firing into exhaust for spool time. The effect of firing together is not nearly as great as I had hoped though based off the data from firing them individually. I think firing them together reduces the flow from each branch as compared to when fired individually, but total flow is still somewhat better. Just not additive of the flow from each branch when fired individually. I think to do that a separate tank would be needed to truly run the systems independently of each other.

I will leave as is though and test at the track to get better data. I do believe the greater result will be from further increasing tank pressure. So far I've tested to 180ish psi. I will test up to 200psi next time at track, my solenoids are rated to 235psi but my pressure gauge and blow off valve are for 200psi so I'll at minimum have to change blow off valve to get over 200psi, which i will do eventually. I just recently found out the konegseg jesko runs 290psi tank pressure, so that alone makes me want to go higher pressures. If more pressure or firing together nets significant gains in spool up at the track I think I'll go ahead and try a clone gtx3582 or gtx3584 to test. My current turbo is a gtx3576 clone which is a 5862.

Also recently got a wild hair and spun up on the lathe another locating bushing for the cam dowel to once again try the exhintake cam, which I said I wouldnt do LOL... This bushing allows for about 2 degrees of change. It looks like the sweet spot on my setup is about 2 degrees retarded from where I had the original cam gear drilled. In testing with it I think it still shows slightly less boost response but possibly very slightly more top end. The differences are small and difficult to test in the small range in which I'm doing a dragy test. I will leave as is to test at track to get better data with it. I'm still not sure if its better or worse overall than stock cam, but data at track will tell.

I still want to test the vanes, and pre turbo water injection. I May test just the vanes next time at track since it only takes a few minutes to install. That would get me good before and after data with same conditions.

Newaza

Small update fellows.

So I went to track today to do some testing and was considering entering a bracket race. It was very hot, That combined with only a few hours sleep last night almost made me not to even go to track, But I wanted to get some solid data on that exhintake swap deal with the new bushing and cam position, so I went.

Well it is confirmed now pretty solidly in my mind that on my combo at least the stock cam is better for overall performance. Trap speed was off about 4mph or so from what it should be at this boost level. Of course the heat (it was 97f today) would account for maybe 1 to 2 mph, but not 4mph. So the cam swap would have to be responsible for the balance of loss. When I street tested new bushing for exhintake cam position with the dragy the difference vs stock cam was hard to measure since I only test for a narrow speed range. The track testing is over a much longer average speed and time which allows the difference to show.

Its kind of strange since the exhintake cam feels by seat of pants to be at least as good as stock cam. The exhintake deal in its current timing position feels to give a slight bump in power at top end. I believe the exhintake cam is down everywhere but at very top of rev range and that bump in power I feel is just going from lower overall torgue in low and mid range and just starting to pull up top. The track data is pretty solid to convince me to go back to stock cam and put this exhintake deal to rest in my mind at least on my combination.

That is really all the data point I have from todays track outing. I wanted to test higher tank pressures and the vanes as well, but didnt. I forgot to bring the vanes, and after the disappointment of the cam swap data combined with the heat and lack of sleep I was ready to call it quits for the day.

I'll get back to track again soon to test a couple more things and maybe start the drive again to push car a little harder to try and knock down some lower et's.

Newaza

Welp fellers, today ended the jatco era for me. Twas a sad day. I have the c4 back in the car and scrapped all the jatco stuff. The jatcos worked well but were just not quite strong enough. Got tired of breaking them. I broke an output shaft recently at my test spot and figured that was enough.

The c4 in the car currently is built with a manual valve body, h servo and extra clutches in forward and direct drum. Should be good to maybe 600hp in a light 4 cylinder car. Unfortunately I did not do a transbrake in this one, but I did just pick up another good c4 to build up. The next one I will build just like the first, but will do a transbrake and maybe a converter dump too.

Also gotta start doing the ford rear setup though as well.

The car currently has a rx7 rear in 3.90 ratio, but working on changing that i near future.

I do have a couple parts I am selling if anyone interested. I have a converter for a 94-97 automatic miata built by florida torque converter that has brazed fins, good bearings and maybe 200-300ish rpm more stall over stock. I also have an ign1a coil setup with bracket and plugs wires. Lmk if interested in those things.