Toys4Life C5

I respect your opinion & that is what this forum is for.

BUT - It pulls so hard at 6k - even with a stock cam, heads & without headers. It would take a ton of willpower IMO not to pull to 6500 (plus you are leaving a TON of HP on the table. Some people pull to 7k - seems risky to me - even with the later & better rod bolts....

Toys4Life C5

Totally agree about the clutch. I think I am going to go with the RST. Good MN winter project. NO 4th gear tuning on the street for me (:-). I only get into 4th WOT at the track. I think I saw knock in 3rd and 4th at the track because the longer you are in WOT, the hotter the combustion chamber temps (and inlet air temps) will get. On the street I am never in WOT that long so I can get away with a little more timing with 93 octane. I am going to mix up some E40 next spring (instead of going to meth) and see if that will keep me from being knock limited in 3rd and 4th in the quarter.. Dyno would work, but I have never had to resort to paying to tune so far... Appreciate your input on springs and P rods. Thoughts on trunnion upgrade? Thanks for all of your input these past few months!!

tabbruzz

So I see what both you guys are saying. So for arguments sake, if I only have my shift points set to 6000 1-2, 6000, 2-3, and 5900 3- 4 should i be concerned with my rod bolts? Do you guys really weld your water pump pulley and replace you power steering pulley? Would I really need to if I limit my shift points as mentioned? I did buy new valve springs, power bond balancer and new alternator bracket just as precations... Again I and shooting for a conservation tune. Not race much if any....

Smoken1

As for the water pump pulley some ppl weld them or you can get one from Jeg's (PRW) and for the P/S pulley go with the C6 pulley

Podium

I agree. Thats why it helps to have tuner that will do a good job and ask questions about the build. I dont change shift points unless the car is built for it.

My car seems to really take off around 4k.

Podium

I replaced my power steering pulley with one from Turn One. The c6 is cheaper and metal. Pin the crank for sure. I did not weld my water pump.

Just leave your shift points where they are and tune the fuel and timing. 75 Lambda WOT (11AFR) and set timing to 12 degrees WOT would be conservative start. I would read plugs and throw it on the dyno if you have time to see what the car truly wants.

Podium

Yeah, 4th WOT is 156mph at 6.8k with the c5z trans lol.

Youre, in MN. Just go full E85. Holiday is the most consitant in terms of E percentage. I never have to adjust the tune if I stay with Holiday Ethanol.


Call up Shardon Performance in Hugo. They will rent their dyno and you can do your own tuning. I got 10 pulls in under an hour. Really nice guys and rates. Ill be going there this spring if I can swing a new engine from TRES this winter.

Toys4Life C5

Good advice. I go to Holiday all the time for my E85 Fiero (11.85 @114). With the Eaton m-90 on it and no intercooler, it needs all the ethanol it can get. For the Vette, I do not think the stock FP and KB BAP will flow enough for E-85 (not positive about this though). I thought I would start with 50/50 mix of E85 and 93 octane and see if the fuel pump can provide enough additional cooling and octane at WOT for the lambda's I am looking and allow for more timing advance no longer be knock limited. Sounds like my combo should run a 125MPH or so fully optimized.

I like tuning at Rock Falls on a test day. $70 and I can let the car cool between runs and tweak the tune making a nice day out of it. More real world for the car too.

What is TRES?

Sounds like you live in MN too. We should get together and make a trip to Rock Falls in the spring?

Podium

The Race Engine Shop. Mike knows his **** and a great dude on top of it. MVP@TheRaceEngineShop is his screen name

That would be fun. Im hoping to go alot next spring and summer. I could only manage 11.2 @136 mph.I couldnt hook in 1st or second at all. Looking forward to trying out the new Viking coil overs.

tabbruzz

sounds good...I plan to have it dyno tuned and checked on the street. Thanks for the advice

tabbruzz

I thought the A&A kit did not have restrictor plates.....Do they??

neutron82

no they don't but you can easily make one... personally I don't think you need them and I'm not really a fan of them but they do allow you to run a smaller pulley to gain more in the midrange since you are spinning the blower harder and limit peak boost on the top end

Toys4Life C5

Neutron - usually you are pretty vocal but you steered clear of the question about the 1999 rod bolts. Do you have an opinion on that matter? Curious what you think...

tabbruzz

Guys, what's your take on speed density? I read different things. Some articles say a SC with 10psi is when you want to start using speed density, others say up to 15 psi before the stock maf is out of range. What are your experiences? I believe if J do end up err on the side of caution I may go 7-9 psi and possible keep the Maf. Andy from A&A has not responded to me yet. I will speak to my tuner to ight as well to see what he can do..

aaronc7

The LS1 PCM has a hard limit of 512 grams/second of MAF air flow, which is ~ 67 lb/min or air ~ 670 bhp. It's not strictly related to boost pressure.

I've read about guys scaling a bunch of other tune tables to get around this limit and keep the MAF in place. Much more common is to ditch the MAF when you get into the 500-600+ hp range and just go speed density. A good speed density tune should be fine and have very minimal downsides.

One downside to speed density in my experience is any sort of airflow mod, you would want to re-tune the fuel/VE tables... a MAF is much more flexible in this regard.

MAF vs SD for me would come down to what your power goals are.

Podium

Speed density all the way.

tabbruzz

are you saying that the 3.6 gives you more midrange then the 3.8? Then perhaps this is the way to go since I want to keep my shift rpms to a max of 6000 or 6100.....Do I have this right? My next question would be how much can the stock a4 with a 3200 stall handle? Now I do not plan on racing much at all, if any and not on drag radials since I dont own drag radials. The car is a weekend toy..thoughts?

neutron82

sorry I must not have seen it, the posts are getting a little busier in here haha... well I'm kinda in the middle on that issue... there's no doubt that putting in some arp rod bolts is a good thing but on the other hand it is quite labor intensive and at that point why not yank the whole engine out and forge it, but keep in mind it gets more and more expensive the further you go down the rabbit hole... it really depends on the person though, some will be super conservative and never rev the car that high because of the bolts or other worries and others are willing to take a risk, personally I don't mind taking a little risk but you also have to understand what you're dealing... heck, I've seen people have more problems with very expensive built engines than they did with the stock one and for the cost of another stock engine it might be worth the risk as opposed to forging and hoping the machine work and assembly was done properly... but like I said, it just depends on the person

the smaller the blower pulley the faster you are spinning the blower which causes it to move more air at a given rpm... some people like to use a restrictor plate when they want to use a smaller pulley to move more air but do not want high peak boost numbers, essentially you will get the gains down low but caps them off at the top... if you restrict the blower too much it can cause your iats to climb, that is one negative... adding an overdrive balancer will accomplish the same thing as a smaller blower pulley so that's one reason you see many supercharged guys running them... here's a cool little calculator you can use to determine how fast you are spinning a given blower in relation to your balancer, blower pulley size, and rpm, https://928motorsports.com/services/selectingpulley.php... my car is a 6 speed and I really don't know enough about autos to recommend anything
, hopefully someone will chime in on that

neutron82

I like speed density, my car has been tuned that way since my blower went on and it runs great... you just really need a good knowledgeable tuner to get it done right... most go to speed density when their power exceeds the maf scale, you also eliminate the risk of breaking the housing apart when you remove the maf haha... a&a actually makes a billet maf housing to prevent that also... from what I understand the maf is more accurate though, maybe an ls3/7 card maf would work better than the stock c5 maf but I don't know the power capabilities of those and what it would take tuning wise to change over to one of those... if you ever plan on spraying meth and keep the maf that is something to think about as well because of the nozzle placement in regard to the maf

tabbruzz

ok, thanks for the info