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95GSXracer said:
Strangely, at 9.0 to 1 to 12.0 to one, I still get .92 volts :)
I guess that underscores Taboo's attitude about the inaccuracy of the stock O2 sensor. Seems like timing and knock are the key tuning tools, and the propane did help both.

May hit the track Sunday afternoon, since I seem to have the traction problems improved. Toying with turning up boost to 23-24, but worried about stock bottom end and trans. Any thoughts?

Joe
 
thanks for that info, it supports the data and logs that IMP got on his VR4. some track times or a dyno pull will tell us whether we are making any more power with it or not.

Joe- i wouldnt be too scared about your bottom end, do you have a 6 bolt? if not even the 7 bolts should be able to hold up to what the 16G can throw at it. the thing i would be a little more worried about is the head floating from the block at that kind of boost. i dont see any ARP head studs or a metal HG in your mod list. those may be something to think about over 20 psi.

thanks again
-Greg
 
6 bolt, no ARP studs or hg, I have read the stock hg is pretty good, but I do need the studs if I go past 22 I suppose. Will do that when I get the head race prepped- 3 angle, porting, etc.

Joe
 
Even on my shite 2g with stretchy bolts, I still ran 25 psi on both the 14b (dropping off to 24) and the 16g. So go for it. Not to say something cant go wrong, just keep your eyes and ears open. But I ran those boost pressures many times for countless 12 second passes. :) If you get any more numbers that would be great. Especially if you start with plain old pump gas. I'm living vicariously through you until I get a kit of my own. I just got engaged, and making my brazilian gf legal is going to cost me bigtime. But I might try to sneak it in with my bonus this month :D
 
Just ran the toluene mix down to empty Sunday night and filled up with 93 so I will log with 93 soon (tomorrow if no rain forecast) and advise. Still hoping to run Sunday afternoon if weather holds, I will need to get it down to quarter tank by then- with fwd every weight difference helps.

As to ARP's, vfaq says this, which makes me think on my 90 I could be ok with stock studs: "This is extremely important on late 92-up 7bolt blocks, as they use stretch-to-torque bolts, that must be torqued to a set value, then turned further to set the correct clamping pressure on the head. In doing so, the bolts stretch a bit." Am I ok since I am 6 bolt? Any other thoughts? In some older threads on studs Taboo has suggested that 12 second cars don't even need the ARP studs.

Also per Haynes and this site OEM are allen head bolts not studs so that makes it seem easier to get the stockers out, right?
http://www.turboclub.com/engines/4g63mods.htm
"M10 bolts with 8mm Allen heads (inset hexagon)." But ffwdconnection say they are 12mm. So does Alamo and everything else I have read. So are the stockers bolts or studs?

This thread makes my plan seem very possible:

http://www.dsmtalk.com/forums/showthread.php?s=&threadid=32799&highlight=arp+stud

It seems like stud replacement if I am not pulling the head but just doing the studs ought to be easy as long as I loosen and tighten incrementally and in the proper sequence. Aren't the stock mitsu head gaskets strong so they don't require replacement when studs are done?

I might put in cams at the same time using the shortcut method per http://www.roadraceengineering.com/instructions/webcaminstructions.htm. Leaning towards HKS 264/264 cams based on reviews. I just don't like the price and I am not sure they make enough difference to justify the $.

Thanks

Joe
 
Thats what I meant above by saying I ran 25 psi on teh stretchy bolts. Actually, a fellow NEDSMers did 410 WHP through a cat onb a frank 5 with stock stretchy bolts. Go figure. But the stock gaskets do have to be replaced once you release teh torque on them. I put a head on, and took it off and reused the same gasket. I never even started it. But the gasket still failed a few months later.
 
Then I will run the stockers since I am 1G 6 bolt, supposedly non-stretch, and just stay below 24psi and focus on tuning and traction setup. Maybe I should torque down the stock bolts if that is a good idea? Thanks.

P.S. Read some of your comments in the earlier cam threads, are you still liking your cams?

Joe
 
I did not go to the track today due to family visiting- maybe next week. I did some logging instead. All runs started middle of second, comments only address 3rd gear logs, which is where knock is worst. Full tank of 93 Octane, about 58* ambient.

Run 1, no propane- 15psi boost slowly creeping to 17, 6-7 counts knock 4800 to 5400, 13 to 16 counts between 5600 and 6300, timing 15 to 18, O2 .90 to .88. No second gear wheelspin these first two low boost runs.

Run 2, propane open 2 turns of needle valve, 2 turns on tank - 15psi slowly creeping to 17, no knock except 2 counts around 6000 , timing 18 climbing to 21, O2 .92 to .90. Car felt smoother. Mild IC heat soak.

Run 3, propane- 20 psi boost, 13 to 18 counts knock between 4900 and 6400, timing 14 to 16, O2 .90. IC heat soaking moderately due to stopping to check logs instead of keeping air flowing through. Second gear wheelspin has returned.

Run 4, propane open 3 turns of needle valve, no log.

Run 5, propane open 3 turns of needle valve- 20 psi, 2-4 counts knock 4800 to 5900, 9 to 13 counts between 6000 and 6450, timing 18 to 20 until 6000 when it dropped to 16, O2 .90 dropping to .88 at 6000. I was very pleased with the way the car pulled during this log. Engine sounded very smooth, and car pulled like it was running ~25% Toluene (about 97.5 octane), not quite as strong as 33% toluene (100 octane). This run was down a slight grade- not sure if that had an impact. I will need to do more logs anyway, hopefully at cooler temperatures to take heat soak out of the equation.

Joe
 
Greg- No doubt the higher boost with the propane makes significant extra power with 93 octane. Besides seat of the pants, the second gear wheelspin with propane is an objective indicator. But I will run the 15 psi creeping to 17 boost without propane and 20 psi boost with propane at the track to try and quantify the e.t. and mph difference. I just need to get my 60's consistent so there will be a valid comparison. My hope is that with the windo welded motor mounts and the VHT in a spray bottle applied before each run the 60's will be a lot quicker and more consistent, so the propane vs no propane will be a more accurate test. Hopefully next weekend if the weather is good. Slicks would help, which ones are you running?

Joe
 
i'm running some 15X8 goodyears i picked up off of ebay for like $80. they arent "drag" slicks so i have to heat them up a little more than if i had a wrinkle wall. then i went to VIP and picked up some 15X7 black steel rims for $15 each. i had a set of mounted slicks for $130...i couldnt argue that. i can't wait to see a few numbers here, wish i could be a help here but ur gonna have to wait till spring.
Greg
 
Even if the short times vary, the mph wil still be close enough to comapre. Especially with the change in boost making a significant increase in mph, so any variance will be a lower percentage. Good info, keep it coming :) My tbelt just skipped and cost me a head. Will be fixed thursday, but that money for the head was my propane money ;) Ah well.
 
Well it will get rid of the carbon build up that was the cuase of all my knock. The root cuase is the valve stem seals leaking while the car is sitting. The oil hardens, before it can be burnt off. I think I posted easlier in this thread about how that allowed me to run 3 psi more boost with no knock, at 22. So this "upgrade" will help the propane do its job, instead of just covering up the underlying carbon problem. :) Its just too bad the propane project has to get pushed out again. With DSMlink I can get some good info, along with other temp and pressure sensors I will be using. :)
 
Kevin-sorry to hear of your timing belt woes.

OK y'all- a short update. I took a quick 25 mile backroad spin tonight. Sorry no logs- left the palm at work. But I am happy to report that in the cool 40* weather with no heat soak the car ran well at 21 psi. It even spun 3rd gear from 65 to 75 without being initiated by steering input. This was 100 octane race gas performance. :)

I boosted as much as safely possible during the 25 mile excursion, and the propane was flawless. It was howeveer kicking in a little early, so I will adjust the Hobbs pressure switch.

It was interesting to watch the a/f blinky gauge shoot up into the green at low boost as soon as the propane kicked in. The effect was less pronounced at high boost, which makes sense due to the open loop pre set maps kicking in then and richening things up considerably even before the propane.

At higher boost I toggled the propane on and off and it changed the gauge by one light, meaning .03 to .05 volts difference. This was more than I saw with the logger based on back to back runs with and without propane, but it may be temperature related, since the denser air was probably more than the ECU and 450's could accomodate. Thus, the propane made more of a difference in the cold air.

I am very pleased so far. :) Anyone running close to the edge on 450s at high boost needs to consider this (or WI) if you plan to run high boost on 93 octane.

Still hoping to get to the track Sunday to quantify the gains. I really don't want to run over 17psi without propane due to knock, so I may test 15-17 without propane against 20-21 with propane. I think this is a fair apples to apples test from a similar knock level perspective.

Joe
 
Pre turbo at 22psi per pressure gauge. I compensate for the lower pressure by opening the needle valve 3 turns instead of 1/2 to 1 turn, so I suspect the amount injected is about the same.

Joe
 
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