85 IROC-Z tpi tuning limitations???
#21
So does the 730 ecm have just as much tunability parameters as the ls1 pcm? I never said you would need an ls1 pcm to go fast. My cousin's car ran 11.83 @ 116 on the old ecu which is not bad cosidering what H/C ls1 cars are doing. I already have hptuners so buying the EFI connection setup would be a breeze to put on and take on a big forced induction build we have planned for it.
Your buddys car must of made 461 on the bottle because we ran just as fast as you with less cam and less cubes on the motor plus it went 11.00 flat with just a 100shot. Full weight with A/C and 3.42 gears. Do you think that big cam was killing the 60ft or something? We are both down south so I doubt the D/A has much to do and the elevation is not a factor.
Your buddys car must of made 461 on the bottle because we ran just as fast as you with less cam and less cubes on the motor plus it went 11.00 flat with just a 100shot. Full weight with A/C and 3.42 gears. Do you think that big cam was killing the 60ft or something? We are both down south so I doubt the D/A has much to do and the elevation is not a factor.
No, I made 461rwhp on motor and 586rwhp on 150 shot with low bottle pressure with my 383 that has a Accel Pro Ram single plane intake I've personally been 11.4X @ 121 mph with a 1.58 60 ft. and 10.3X @ 131 mph with a 1.54 60 ft. on a 150 shot hitting the spray in 2nd gear not out of the whole. I just got a progressive controller and hoping for a 9.9X pass when I up the shot.
#22
TECH Veteran
iTrader: (11)
Sorry about the double post. Didn't think of this earlier.
How difficult is it to swap the flat tappet lifters for 87 roller lifters? Can we use the rollers on the flat tappet style cam? What about oiling, any port alignment issues, lifter to block? Am pretty sure that we would need to re-measure pushrod length. That's no big deal. Am thinking that the biggest issue could be whether or not the roller lifters work on the existing cam. If not, who makes a roller cam w/ very similar to the 85 flat tappet cam specs?
How difficult is it to swap the flat tappet lifters for 87 roller lifters? Can we use the rollers on the flat tappet style cam? What about oiling, any port alignment issues, lifter to block? Am pretty sure that we would need to re-measure pushrod length. That's no big deal. Am thinking that the biggest issue could be whether or not the roller lifters work on the existing cam. If not, who makes a roller cam w/ very similar to the 85 flat tappet cam specs?
To convert that block to roller would be a chunk of change and not worth it to me for a 305.
#24
OK, thanks.
BTW, am looking for a re-manufactured set of 305 heads, 64cc or a little smaller (76-85), (4) bolt radial valve covers (not center bolt). Will pay $200 shipped & provide you with a set of cores assembled (w/ valves, guides, springs) shipped @ my expense. Have Paypal & a perfect trader rating. Posted in the appropriate WTB sales section. Wanted to note here as well. PM, call or text 937-242-5493. Location North East, Ohio.
BTW, am looking for a re-manufactured set of 305 heads, 64cc or a little smaller (76-85), (4) bolt radial valve covers (not center bolt). Will pay $200 shipped & provide you with a set of cores assembled (w/ valves, guides, springs) shipped @ my expense. Have Paypal & a perfect trader rating. Posted in the appropriate WTB sales section. Wanted to note here as well. PM, call or text 937-242-5493. Location North East, Ohio.
#27
Making progress. Am replacing the crank. It's not completely horrible, but, new are $150 or less & makes selecting replacement bearing size easier. Boy, those stock cast ridges behind the inlet of each TB blade are huge. Unbelievable some of the stuff cast into stock parts. Can see how grinding them down helps. Oh, & 2 bolt mains...really??? Wow, thought even a little 305 would use @ least 4 bolt mains. Maybe that's why the crank main journals were exponentially worse than the rod journals.
#28
My current project is based off a 2 bolt block with splayed 4 bolt caps. It is stronger than the stock 4 bolt blocks. 2 bolt blocks have beefier main webs.You should check out Eagle cast cranks, they only run about $168 through Jegs.
http://www.jegs.com/i/Eagle/356/1035...oductId=755263
All american vehicles with 305's were 2 bolt. Some Canadian trucks got 4 bolt main 305's, but only for one or two years.
http://www.jegs.com/i/Eagle/356/1035...oductId=755263
All american vehicles with 305's were 2 bolt. Some Canadian trucks got 4 bolt main 305's, but only for one or two years.
#29
My current project is based off a 2 bolt block with splayed 4 bolt caps. It is stronger than the stock 4 bolt blocks. 2 bolt blocks have beefier main webs.You should check out Eagle cast cranks, they only run about $168 through Jegs.
http://www.jegs.com/i/Eagle/356/1035...oductId=755263
All american vehicles with 305's were 2 bolt. Some Canadian trucks got 4 bolt main 305's, but only for one or two years.
http://www.jegs.com/i/Eagle/356/1035...oductId=755263
All american vehicles with 305's were 2 bolt. Some Canadian trucks got 4 bolt main 305's, but only for one or two years.
Thanks for the comments. Have been thinking about what you said regarding the splayed caps since reading this afternoon...If ever an argument could be made for ARP main cap bolts, a (2) bolt main would be the candidate. Basically, am thinking about a main cap bolt upgrade as opposed to a splayed cap. I just wonder if adding a couple thou to the main bearing clearance would be required. Have not yet looked up the main cap stock bolt torque specs, but, measured 90 Ft-# before removing the main caps. Can't imagine that ARP's would require any higher. Guess I'll be looking up the specs to see. Am thinking that the ARP's are a higher tensile & yield strength than the stockers & required more torque. We will see.
#31
TECH Veteran
iTrader: (11)
Thanks for the comments. Have been thinking about what you said regarding the splayed caps since reading this afternoon...If ever an argument could be made for ARP main cap bolts, a (2) bolt main would be the candidate. Basically, am thinking about a main cap bolt upgrade as opposed to a splayed cap. I just wonder if adding a couple thou to the main bearing clearance would be required. Have not yet looked up the main cap stock bolt torque specs, but, measured 90 Ft-# before removing the main caps. Can't imagine that ARP's would require any higher. Guess I'll be looking up the specs to see. Am thinking that the ARP's are a higher tensile & yield strength than the stockers & required more torque. We will see.
#32
^^^
Yes, I know. Breakaway was 120 ft-# & I subtracted for an estimate. Am going to studs not so much for the higher yield stud, but more for the lack of twist or torquing within the block. The stud allows for just the vertical load to be transmitted into the block; not the vertical + torsional load that takes place when tightening a bolt into the tapped hole in the block. That's what was & is more appealing to me considering 2 bolt mains. Again ,the alarming thing was the difference between the condition of the rod journals compared to the main journals on the cam. Don't know for sure that it was 2 bolt main movement related, but the main journals were much worse.
Yes, I know. Breakaway was 120 ft-# & I subtracted for an estimate. Am going to studs not so much for the higher yield stud, but more for the lack of twist or torquing within the block. The stud allows for just the vertical load to be transmitted into the block; not the vertical + torsional load that takes place when tightening a bolt into the tapped hole in the block. That's what was & is more appealing to me considering 2 bolt mains. Again ,the alarming thing was the difference between the condition of the rod journals compared to the main journals on the cam. Don't know for sure that it was 2 bolt main movement related, but the main journals were much worse.
#34
#36
TECH Veteran
iTrader: (11)
Now if you putting the compression at 15.5:1 and putting on some 265cc 15* heads and a huge solid roller and plan on spinning it to 9600 rpms, then by all means 4 bolt splay it and use ARP hardware. I just don't see the need for ARP even if it was 29 bucks. 75 ftlbs is 75ft lbs no matter the fastener. Now if you are talking about bolt stretch, then thats different but I doubt you will stretch the stock bolts for what you are doing.
#37
Kids today..
#38
I'm no kid. Thanks for the replies, all the same. It's not about reaching the limits of the bolts, it's about limiting the deflection of the cap, thereby reducing the clearance between the crank & the bearing. I understand that it's overkill & do appreciate the comments. Everything has been ordered w/the rod studs being the only "overkill". Should be a good little runner.
We ended up w/ close to 10:1 SCR w/a mild cam & LT headers. As noted, don't want to move so much air through it that it can't be tuned w/ fuel pressure & timing. Don't want to spend another few hundred on a new operating system.
Thanks again. Will complete the build maybe by the end of this coming weekend. Won't be installed & running 'till spring.
We ended up w/ close to 10:1 SCR w/a mild cam & LT headers. As noted, don't want to move so much air through it that it can't be tuned w/ fuel pressure & timing. Don't want to spend another few hundred on a new operating system.
Thanks again. Will complete the build maybe by the end of this coming weekend. Won't be installed & running 'till spring.
#39
TECH Veteran
iTrader: (11)
No matter what fasterner you put in there you still have the same bearing cap that was put there 25 years ago. You are talking about cap deflection but no matter the bolt it won't stop what you are trying to stop. You can use a titanium kryptonite impregnated bolt and it still won't stop what you are describing you are trying to stop because you are still using the same ol'cap.
If you used aftermarket billet mains then we are talking a different story since the cap is now made of a different material that is stronger.
In other words you are building a road race car with all the best suspension mods but then you put p155/60/r14 tires on the car.
Good luck with the build anyways man. If I ever need to build a house in an earthquake prone area I know who to contact. You will build it to withstand a 11.5 richter scale quake!
If you used aftermarket billet mains then we are talking a different story since the cap is now made of a different material that is stronger.
In other words you are building a road race car with all the best suspension mods but then you put p155/60/r14 tires on the car.
Good luck with the build anyways man. If I ever need to build a house in an earthquake prone area I know who to contact. You will build it to withstand a 11.5 richter scale quake!