reddragon71

Looking for critique and opinions/suggestions on my current bud...going for a streetable max effort pump gas 347 nitrous set up, its all about ready to go jn the car other than a few odds and end....just getting anxious and wanna hear some opinions on how everyone thinks it will run....specs are as follows

ls1 block at 3.905-
Polished ls1 crank-
Eagle h beam 6.125 rods-
Wiseco flat top forged pistons (roughly 11:1 static)-
Wiseco gfx rings-
Arp head and main studs-
Cloyes timing set and ported ls6 pump-
comp 239/250 .624/.619 114+4 cam
Cometic mls .040 head gaskets-
TEA Stage 2 243 heads flowing 325+cfm-
2.02/1.59 ferrea valves and .650 pac springs-
Comp trunion kit and hi tech chromoly pushrods-
Gasket matched edelbrock super victor-
Accufab 1350cfm 4150tb
Edelbrock stepped long tubes to a cutout to a catback-
Svo green top 42lb injectors-
Nitrous outlet puck system ( going to be spraying 200-300)
Ngk bp9es plugs at .027-
AES rmvb/tbrake TH350 and custom driveshaft-
Custom midwest billet nitrous stall (4000 2.44str)-
Moser m9 with 4.11s-
28×10.5 et drag-
3300lbs

TeEnAgE pHeNoM

iTrader: (6)

How high are you wanting to spin it? Also are you going to spray 200 or 300 because cam profiles will need to be different.

You'll also need a converter that goes to within a few hundred rpms of peak torque. It probably needs to go to 5400-5500 on the kit. Maybe more depending on how high you want to spin the motor.

reddragon71

The converter is being setup to flash to roughly 5000...and the whole setup is being built around 300...but it will see 200 or less on the street

reddragon71

And im planning to shift around 7400 max

TeEnAgE pHeNoM

iTrader: (6)

Setting one up for 300 and then spraying 200 is going to disappoint. Just get a progressive controller and leave on less power on the street.

I don't think 5k flash speed is enough with your combo. I have mine going to 5200 with a 3.06 first gear. You need a higher stall speed with the taller first gear.

Who spec'd the cam btw?

Sales@Tick

iTrader: (3)

Seems like a bit late of an intake valve close event for a 200-300 shot and a converter that is only going to flash to 5000rpm.

I'd want the converter to flash to around 5800rpm possibly even 6000-6200rpm with that intake closing event and a shift point of 7400.

In a "max effort" application you want your flash speed to be near to where your engine falls back to on the shift.

This doesn't make for a nice driving converter, but it will run it's tail end off at the track on the kit if it's done correctly.

I also think you need a lot more gear than a 4.11. I'd have a 3.70 in it to start with.

reddragon71

Yeah im certainly concerned with it being too much gear, going to try it out and have some 3.70s on the to do list for sure...ill speak with midwest about the converter (havent ordered it yet) but this car will see a lot of street time and will be driven to and from the track, so that was also a factor.....I really dont believe 200-300 is enough of a difference in this caliber of nitrous to make a lesser shot dissapoint in any way, but I could be wrong...its running a timing tuner currently but will eventually be set up with a leash progressive setup

reddragon71

The cam was my own spec derived from suggestion direct from comp cams and bullet cams

TeEnAgE pHeNoM

iTrader: (6)

If you're concerned with converter size being too large for street driving then you should have went with a cam that made more low end power. Also there is a pretty good difference when setting up gear and converter when you're talking about going from 200 to 300 shot as well as cam profile. Above 275 is when you start getting into needing a nitrous specific cam profile.

But what do Martin and I know about setting up a car. Lol.

reddragon71

The cam profile was chosen to avoid excessive low end (the car is regularly street raced) and I was under the impression a 300 shot would make up for the cams powerband down low.....should I call ptc and get their opinion on a converter?

TeEnAgE pHeNoM

iTrader: (6)

Yes, a 300 shot would certainly help a lazy engine in the low rpm range but are you going to spray all 300 out the gate? The converter still needs to be matched to the rpm range of the engine because even though it's a nitrous car the engine still needs to be happy going down the track (ie flash speed, and shift extension).

I've been through this. When I first swapped converters in my car the one I received was way too tight (2600 flash on motor and 2000 rpm shift extension). Even spraying an .088 jet and .093 jet and leaving on all power the converter still only went to 3800-4200 and had a 1300-1400 rpm shift extension. This resulted in a huge loss in ET and MPH on motor 12.20 versus 11.40 with the SS3600 I was running before and even with the spray it didn't pick up to where I wanted it. The car went from 1.58 60' on motor to 1.82 but still 60' the same on spray (1.38-1.42) however the large shift extension killed 330 and 1/8 mile time. It only went 9.92@132 on .093 jet when it had gone 9.84 on a .078 jet with the old converter. I had the converter restalled (3500-3600 on motor and 4800-5200 on spray with 750-800 rpm shift extension), changed cams, and did a little weight reduction and I went 1.23 60'.

Regardless of how much spray too tight of a converter can really kill a car as well as develop a ton of wheel speed and make it extremely hard to hook.

My advice is to set the car up for the size shot you're going to spray the most and let it eat.

Just trying to help you out and Martin and I have both been pretty quick with cam only and spray setups.

reddragon71

I appreciate the advice so far, im not against a looser converter, and I do spend a lot of street time NA playing around...but wouldnt a looser converter on spray have a theoretical tendency to blow through and lose mph?

reddragon71

Another advantage of midwest is they do free restalls, so I can try and dial everything in and test accordingly and if necessary send it in at the end of the season

TeEnAgE pHeNoM

iTrader: (6)

It won't necessarily be "loose" on the motor. You just want it to flash to the proper rpm on the spray. If the converter is setup right then you can get a high flash speed but still get killer efficiency (4-6%). Some of the guys making big power have converters that flash to 7k or higher but they are still getting 2-3% efficiency.

A good converter company can get one really close just based off the specs you give them as long as they are accurate specs. I'm not saying it won't need to be restalled to get it perfect but it will be close.

The truth is in most applications like ours (low hp and street driven) we don't have the proper means to collect the correct data in order to get a converter stalled perfectly.

reddragon71

So overall you guys would suggest lower gears and a higher flash on the converter? ill call midwest and double check the specs they quoted me

Dustin11

Bottom line. If you get a converter built for a 200-300 hit, it will be a slug NA. If you built it to run great NA, you will blow through it with a 300 hit. Pick something in between and it will work but will not be optimized for either. To go further than that, you will want an 8" converter to work great NA but it would be to loose for street driving. You can get away with a 9-10" converter that will work great on spray and will drive much better without overheating the trans.

reddragon71

The converter they have spec'd for me is a 9.5in

Dustin11

Most likely a GM245mm core. I like a 10" with a high flash stator for an application like this. They drive pretty well but will still flash well when hit with a healthy shot.

Sales@Tick

iTrader: (3)

Listen to this guy.

He does my converters.

reddragon71

Wilk the 9.5in and 10in perform much differently, though?