Trying to tune my hx35/ ht3b combo.

[LandTug2]

No idea why it posted 5 times sorry for the clutter guys.

[Remps]

Collar still on the fuel screw?

[LandTug2]

No took it off a while ago. I hear the setup is slightly different with the intercooled vs non intercooled trucks and some need to be re indexed to get full fuel pin travel (close to run away)

[Remps]

I think most IC fuel screws bottom out before getting runaway. I don't think re-indexing is required unless you have a longer unclipped 4200 gov spring. Some re-index to get more throttle travel, I just chop the high idle stop off the linkage. It is possible to have too much throttle travel though, and actually lose power. As for your fuel screw, turn it in already! Always beware of runaway, and if you start to feel resistance turning in the screw, stop, and turn it back out a hair. If it were mine, I'd keep both turbos under 35 psi. If full fuel brought it over 70 psi total, I'd add a little more timing to try and bring it back to 70ish. Remember, max volume from the hx35 is around 30 psi, at 52-54ish lbs/min, down to 40-42 lbs/min at 43-44 psi, and nearly off the map on the compressor, with high drive pressures. 35-38 psi is just fine for a single hx35 though, and it'd produce more power than at 30 psi. With twins? MAYBE your secondary would be better off at 30 psi, I really couldn't say. Only one way to find out and that's to tune it and run it. Never seen a map for a 3b, but it's gotta be good for at least 35 psi of good air, maybe 40.

[LandTug2]

Well that's the thing, Its all the way in and bottoming out but no indication of run away. Was hoping re indexing will allow me to take it a bit further and get it closer. When it was screwing in it got really still all of a sudden so left it like that for a bit but didn't feel comfortable with it so backed it out half a turn. Think Ill back it out further. I searched High and low for a map for the HT3b and only came up with an HT 60 map. I agree through, I believe I found somewhere that it is good up to 52 pounds of air. Whether that's the case or not... I guess I am seeing about 30 out of the Hx35 but that's with that stupid boost leak out of the compressor housing. Any ideas how to fix that? Like I said above, thinking of getting some thin brass sheet and cutting out a gasket to sandwich in there. Plan is to put the fuel to it then increase timing until it cleans up full tilt smoke.

[oldestof11]

You're running a 2:1 ratio on the compressors which is about the sweet spot. You may see more with more fuel but I doubt it will run as cool

[LandTug2]

Yea that's true. Maybe need to seriously start thinking about port and polishing the head and exhaust manifold. Was really expecting the new intercooler and piping would help bring down the egts. Also hoping opening up the last 2.5'' restriction in the intake will help it breath better. I heard adding timing will make it look like the egt's are lower but instead its increasing the temperature in the combustion chamber correct?

[LandTug2]

Also, any of you guys running manuals? I have been reading around about launching with a manual transmission and seems the general consensus is to do a clutch dump with higher rpms for the best launch (short of doing a boosted launch) sound right? Sorry off topic but just wanted to know as I plan on hitting the strip soon at some point.

[oldestof11]

I held RPM at 3500 and did more of a controlled "dump". I was fully out and accelerating at 60'. However, I had a stock turbo.

[AHineman]

Dropping the clutch at high rpm sounds like a great way to get a chance to see the insides of a getrag.

[Remps]

You'll want to launch at mid to high rpm, 3rd gear good clutch, stock clutch..2nd at mid rpm. As oldest said, a controlled release. Slip clutch slightly before launching, just enough to take slack out of the drivetrain at least, this will greatly help avoiding gutbag/rearend explosions. You want to get the clutch engaged as quickly as possible without bogging the engine, In under 1.5 seconds. (2nd gear launch different story) Get in the throttle and get the clutch engaged. Boosted launches are possible with a manual and a good clutch, but don't expect it to last too many passes. And pointless with a 2wd anyway.

[LandTug2]

Good info guys! Thanks for the tips on launches. Plan on taking it to the local drag strip to do some test and tune pulls. I know I most likely won't be able to keep pace with the auto or 4wd guys but will sure fun trying . I would be happy to break 14 seconds so I would have an excuse to buy a helmet... haha. I am sure its a long way from that.

[LandTug2]

Remps, when you say "good clutch" would my OFEK do the trick or would a duel disk be what your referring to? Also, is a 3rd gear launch more efficient than a 2nd gear launch? What kind of rpm we talking about hear for the launches? I tried a 1500 rpm launch and it burned the tires starting in 2nd. I didn't mean to derail the thread. As far as the compounds tuning havn't had much time to get in there to work on it

[DMan1198]

It's your thread man. That basically gives you the right to derail the thread as much as you want

[LandTug2]

Haha good to hear! Going to try and get under the hood today some if possible. I put a little washer under my fuel pin to help push the ramp down just a hint as it looks like I wasnt getting to the lowest part of the fuel pin. Star wheel is about 4 turns out from stock. Was seeing a bit of fuel on the pin but since putting the THD pin in its gone away. Step in the right direction!