RiGs2G said:

For whatever reason my car knocks like crazy above 20psi on pump gas. It just doesnt like it. I dont have any timing control at the moment. I am running DSMchips EPROM to compensate for my injectors and then a SAFC to fine tune the A/F ratio on my wideband.

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You need timing control to run over 20psi. I had the same issue with my car. I am only running 13* timing max at WOT.

joyfil2001 said:

You need timing control to run over 20psi. I had the same issue with my car. I am only running 13* timing max at WOT.

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Ok, but my real issue is not being able to control boost under 20psi.

I would get the supporting mods to run more boost, as low boost just doesn't make sense anyways. You could always just put in a 1G cas and use it to dial the timing back a couple degrees.

If you want low boost, you should run a 16g.

. . .But I'm still confused. I culd run 5psi peak with my bolton h1c. . . It felt like a turd too.

RiGs2G said:

Ok, but my real issue is not being able to control boost under 20psi.

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Have you tried running off just the wastegate to see if maybe your boost controller isn't working?

Just FYI for anyone looking to buy an H1C, there is one with an 8 blade 46 mm inducer compressor wheel as well, so make sure you measure the inducer before buying one. There is a picture with measurement (not mine) here: Just Purchase my Holset HE351VE Turbo. I suggest it be added to the Holset FAQ.

We all know there is a 45-46mm h1c, the baby h1c. BTW the pic of the hx35 in that thread is actually of a small h1c. 52mm inducer. Bottem line, it is what it is.

We all know of the various size holset compressor wheels. Come here for the information. It's all there. . . Now when someone spits out a map of the baby/small/big h1c , since they have an "in" at holset, then we can add information. . . In the mean time, I have my speculation as to what the big h1c map is from another named map from holset. Like the hx30 maps represent the hx35 wheels.

Regardless, nothing there is fresh "news". . . Just more speculation and less accuracy. Than x for the pic of the small h1c. you can see how well it is shaped vs. other compressors like the evo3 16g and 18g and gt28rs compared.

We all know there are various sizes, yet it doesn't state it in the FAQ and I believe it should, hence why I brought it up. If one didn't know any better (me, for example, who doesn't bother to read through every 1000 post Holset thread) they would be led to believe that there is only a small and big H1C.

You now know

I will attempt to clear the air like I have been for years . . .

joyfil2001 said:

Have you tried running off just the wastegate to see if maybe your boost controller isn't working?

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Yes, right now Im not running a boost controller, just a line straight from the compressor housing to the WasteGate

RiGs2G said:

Yes, right now Im not running a boost controller, just a line straight from the compressor housing to the WasteGate

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It's got to be a faulty wastegate then. If you are sure there is a 10psi spring in there, it should not build any more than that.

I have an HX35 with a Tial 35mm. If I set it at 20psi, it stays at 20psi. If I set it at 17psi, stays there too.

Did you port out the wastegate hole or anything?I wonder if the housings set up for external are different (besides the obvious) from the internal?

I had an ebay 44MM external off the o2 housing on my 1G (bolton H1C), and it would creep to 27-30psi; the exact same setup now on my 2G instead creeps to less than 20.

Speaking of wastegates(my excuse to hijack the thread again, I apologize) I just got some pics:




Divider was filled down so it was the same profile as the bottom of the wastegate valve.

Holds anything past 13 psi like a champ, otherwise it will creep to 13 by 7k. Threw a different(better) boost gauge in and it was actually only hitting 22 psi, which is starting to push the 1000cc's on e85. Will try to eek out 25 psi at 12:1 AFR for the shootout and see what she'll do.

^That is awesome.

Mr Peepers said:

Threw a different(better) boost gauge in and it was actually only hitting 22 psi, which is starting to push the 1000cc's on e85. Will try to eek out 25 psi at 12:1 AFR for the shootout and see what she'll do.

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There's nothing wrong with running 12.5:1 if not leaner.

Agreed. I run at least 12.5:1 now on E85 with my 2.3l and 16g

joyfil2001 said:

It's got to be a faulty wastegate then. If you are sure there is a 10psi spring in there, it should not build any more than that.

I have an HX35 with a Tial 35mm. If I set it at 20psi, it stays at 20psi. If I set it at 17psi, stays there too.

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I pulled the wastegate off and took the spring out. Its the large red spring which according to Tials website is 11.6 psi. I hooked my air compressor up to it, after I got it all back together, and it opens just a little bit at 20psi and is fully open at 25psi. All the seals looked good and it didnt leak anywhere. What spring is everyone running on their tial? Thanks

RiGs2G said:

I pulled the wastegate off and took the spring out. Its the large red spring which according to Tials website is 11.6 psi. I hooked my air compressor up to it, after I got it all back together, and it opens just a little bit at 20psi and is fully open at 25psi. All the seals looked good and it didnt leak anywhere. What spring is everyone running on their tial? Thanks

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You just found your problem. Your wastegate should blow open at 11.6psi. You are saying it is only opening at 25psi with the air compressor. That is exactly what it is doing on your car too. You have a faulty wastegate.

How is it faulty? the diaphram is good and everything looks ok. What else could be wrong with it? Thanks

RiGs2G said:

How is it faulty? the diaphram is good and everything looks ok. What else could be wrong with it? Thanks

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My only guess is that spring isn't correct, or just not doing it's job. Was it modified in any way? You can order a new Tial spring and see if that solves your problem. Have you tried calling Tial?

It isnt modified in any way. Ill try calling Tial. Maybe the spring is bad? But normally springs go soft not stiffen up.. I can order a new spring but I hate just "throwing money" at it. Thanks

I know what you mean. But you definately narrowed down the problem to the wastegate. Is there anyone local to you that might let you try and use their spring?

Nobody local is running a Tial Wastegate that I know of. Ill see what I can find. I just sent Tial an email (they dont have a number listed on thier site) so hopefully they will get back to me soon.

Got two runs in yesterday at the shootout. 25 psi running around 12:1afr although I didn't really get time to do any logs. Street tires.

First pass left the line at 4.5k 2 step which was a bit low so I feathered it into boost.

[email protected] with a 1.75 60' Shifted into 5th(seemed like a good idea at the time)


Second pass I set the rpm to 5k and lost traction, bounced off rev limiter for a sec and short shifted into 2nd. Got a worse 60' but held out 4th this time and gained some mph. Left my passenger side window down on accident for whatever it's worth

[email protected] with a 1.78 60'

After that was qualifying and took slow motion videos for /J while he used his other camera. He wasn't set up when I ran so the second run is in slowmo from the stands and FenixTX got some video from the staging lanes.