Holset Turbos, PART 3

[Slippi84]

When do HX40 guys with 18cm hosuing usually see full boost?

[dsm-onster]

There's really no DSM recorded with an hx40 running a holset housing. The small bep bolton housing on the hx40 has seen +650whp. With nearly the same spool speed as a gt30r.

[Slippi84]

Originally Posted by dsm-onster

There's really no DSM recorded with an hx40 running a holset housing. The small bep bolton housing on the hx40 has seen +650whp. With nearly the same spool speed as a gt30r.

Yeah but a bolt on housing isn't an option for me because one i'm not 4g63 and two I already have a t3 manifold.

[ceedawg]

Originally Posted by Slippi84

Yeah but a bolt on housing isn't an option for me because one i'm not 4g63 and two I already have a t3 manifold.

In the honda threads you will find quite a few guys using the the 16 and18cm housing on the even smaller HX35's and getting full boost in the 4k and higher range with a 1.8L motor.

Their mani's are non divided I wanna mention.

There is another honda guy with a 16cm housing on a HX40 6blade with a 1.7 or 1.8L Vtec that claims full spool at almost 5k but remember these V-tec motors don't have the bottom end grunt that our 4g63's have. I tend to think that our cars would have full boost earlier than the honda guys due to displacement and head design.

He also ran 11.00@134mph 2600lbs 25psi. mixture of 93/110 octane fuel no sleeves.

The guy in the links I posted show where he makes full boost in his honda with a 18cm housing HX40/35 setup if you go and chk out the link. He even has a dyno posted as well.

I say screw the .55 BEP turbine housing it just creates to much heat and back pressure which basically over the long hall kills the motor. They are prone to cracking as a result as well.

[ceedawg]

Originally Posted by dsm-onster

There's really no DSM recorded with an hx40 running a holset housing. The small bep bolton housing on the hx40 has seen +650whp. With nearly the same spool speed as a gt30r.

Because (which you already know), it's new to us but very popular with the honda guys.

[Slippi84]

Originally Posted by ceedawg

In the honda threads you will find quite a few guys using the the 16 and18cm housing on the even smaller HX35's and getting full boost in the 4k and higher range with a 1.8L motor.

Their mani's are non divided I wanna mention.

There is another honda guy with a 16cm housing on a HX40 6blade with a 1.7 or 1.8L Vtec that claims full spool at almost 5k but remember these V-tec motors don't have the bottom end grunt that our 4g63's have.

He also ran 11.00@134mph 2600lbs 25psi. mixture of 93/110 octane fuel no sleeves.

The guy in the links I posted show where he makes full boost in his honda with a 18cm housing HX40/35 setup if you go and chk out the link. He even has a dyno posted as well.

I say screw the .55 BEP turbine housing it just creates to much heat and back pressure which basically over the long hall kills the motor. They are prone to cracking as a result as well.

The ad says it's a v-band but it doesn't look like one to me and there aren't any other pictures showing teh exhaust side???

[dsm-onster]

Originally Posted by ceedawg

In the honda threads you will find quite a few guys using the the 16 and18cm housing on the even smaller HX35's and getting full boost in the 4k and higher range with a 1.8L motor. . .

If anything, the honda guys will get full boost earlier because of head design and high lift cams. Full spool to the average honda setup is 6-8 psi. By 5K? that's not good. Even for a 1.6L . That is what I've seen. Full spool by 4K or more with a MUCH smaller hx35 in an 18cm^2 turbine housing, is going to leave you at 5K for the hx40. NOT good. Not for the poorer flowing head designs we DSMers use.

The 4g63 won't get spool earlier. It will be about the same as any other 2.0 honda. Can you imagine only stock boost or less by 5000rpms? You'll have a peaky engine that will do terrible at the track.

TimG, a moderater here sees 20psi by 5200rpms with an hx35 in a 12cm^2 holset housing after porting the housing inlet. Non-divided runner exhaust manifold with 272s and stock intake manifold (better for spool). I see 20psi with my nearly identical h1c by 3500rpms with the bep housing, milar cams, the same intake manifold, and an evo3 exhaust manifold. My small bep housing isn't showing any signs of restricting my setup AT ALL. I've found out a little trick now to get the weak sprung ebay external gate to hold to whatever boost I want (a little different from the way TiAL recommends with a MBC). No blowing open or drop in boost at 8K so far.

Where would Slippi84 be?. . . with a much bigger turbine wheel, a much bigger turbine housing, a much bigger compressor wheel. And probably a little less flowing head. Likely with an intake manifold upgrade. Most imporantly for Slippi84, the small bep housing has proven itself with the hx40. Why don't you like it? Heat spins a turbine wheel. No one has recorded the backpressure. We don't know if it's too much.

I'd run a MUCH smaller divided housing with a non-divided runner manifold. Or get a divided runner manifold. Or get a bep housing. All would be better. Spool is overrated especially for a track vehicle. But NEEDLESS spool is a waste IMHO. And doesn't help you get down the track faster.

Originally Posted by Slippi84

Yeah but a bolt on housing isn't an option for me because one i'm not 4g63 and two I already have a t3 manifold.

There's a .70a/r t3 bep housing. The small .55 a/r housing on an hx40 is good for 650whp and you can still get them in various forms including t3 inlet. Call to be sure.

Like in my pm, the reason why you don't want to run a divided housing with a non-divided manifold is because the exhaust pulses will see twice as much turbine housing area. The 18cm^2 turbine housing is about twice the size of a .63 A/R housing. See some basics on twin scroll housings I've posted.

I could be totally wrong. That pic isn't very detailed. But, that looks like an hx35 to me. What is the compressor inducer and turbine exducer diameters?

[Slippi84]

Originally Posted by dsm-onster

If anything, the honda guys will get full boost earlier because of head design and high lift cams. Full spool to the average honda setup is 6-8 psi. By 5K? that's not good. Even for a 1.6L . That is what I've seen. Full spool by 4K or more with a MUCH smaller hx35 in an 18cm^2 turbine housing, is going to leave you at 5K for the hx40. NOT good. Not for the poorer flowing head designs we DSMers use.

The 4g63 won't get spool earlier. It will be about the same as any other 2.0 honda. Can you imagine only stock boost or less by 5000rpms? You'll have a peaky engine that will do terrible at the track.

TimG, a moderater here sees 20psi by 5200rpms with an hx35 in a 12cm^2 holset housing after porting the housing inlet. Non-divided runner exhaust manifold with 272s and stock intake manifold (better for spool). I see 20psi with my nearly identical h1c by 3500rpms with the bep housing, milar cams, the same intake manifold, and an evo3 exhaust manifold. My small bep housing isn't showing any signs of restricting my setup AT ALL. I've found out a little trick now to get the weak sprung ebay external gate to hold to whatever boost I want (a little different from the way TiAL recommends with a MBC). No blowing open or drop in boost at 8K so far.

Where would Slippi84 be?. . . with a much bigger turbine wheel, a much bigger turbine housing, a much bigger compressor wheel. And probably a little less flowing head. Likely with an intake manifold upgrade. Most imporantly for Slippi84, the small bep housing has proven itself with the hx40. Why don't you like it? Heat spins a turbine wheel. No one has recorded the backpressure. We don't know if it's too much.

I'd run a MUCH smaller divided housing with a non-divided runner manifold. Or get a divided runner manifold. Or get a bep housing. All would be better. Spool is overrated especially for a track vehicle. But NEEDLESS spool is a waste IMHO. And doesn't help you get down the track faster.


There's a .70a/r t3 bep housing. The small .55 a/r housing on an hx40 is good for 650whp and you can still get them in various forms including t3 inlet. Call to be sure.

Like in my pm, the reason why you don't want to run a divided housing with a non-divided manifold is because the exhaust pulses will see twice as much turbine housing area. The 18cm^2 turbine housing is about twice the size of a .63 A/R housing. See some basics on twin scroll housings I've posted.

I could be totally wrong. That pic isn't very detailed. But, that looks like an hx35 to me. What is the compressor inducer and turbine exducer diameters?

.

I really didn't know that they made a .55ar w t3 hook that could be my meal ticket

[dsm-onster]

Call Tim's Turbo first. Nick at The Turbo Trader said that BEP no longer makes the t3 flanged small housing. . . It's not that they can't make it. It's just that there's not enough demand.

Certainly after seeing what badman21 has done with the small housing, the dsm community would look at these housings with a different approach.

[Slippi84]

WHich is more effecient the 7 blade or the 6 blade hx40?

[Slippi84]

Originally Posted by dsm-onster

Call Tim's Turbo first. Nick at The Turbo Trader said that BEP no longer makes the t3 flanged small housing. . . It's not that they can't make it. It's just that there's not enough demand.

Certainly after seeing what badman21 has done with the small housing, the dsm community would look at these housings with a different approach.

I did and he said he's all out....... It's a bad housing anyway no one should even attempt to buy one lol

[andy4g63]

As I posted earlier my H1e/8blade/60mm inducer, with a 280'S and JMF SMIM gets 21-22psi @ 5100RPM IN 3 GEAR. My timing actually wasn't 17-`18*, as I thought, it is 13* at the redline. That is conservative, but there was litlle misunderstanding on my side. Even with a little more timing-17-18* by redline and a little more leaner AF ratio before full boost and something else that I don't know about it, I will get full boost MAY BE few hundred RPM earlier, but this is speculation. I don't know what BEP 0.70 AR turbine housing equals to in Holset"s own 12cm;14cm or 16cm, but anything more than that0.70 AR is appropriate only for a full drag race car.

You can't get it to spool earlier, and WHY would you need a car that makes boost by 6K, even if you make good power. As we speak my car is in TOP shape, there is no single thing that needs to be addressed. So I don't see any reason to doubt my motor for later spool.

I don't have any idea how these Honda gus get it to spool so early, but if any of you guys can, than in my opinion can use 16 or 18cm Holset housings, otherwise is going to be plain boring.

[ceedawg]

Originally Posted by dsm-onster

Full spool by 4K or more with a MUCH smaller hx35 in an 18cm^2 turbine housing, is going to leave you at 5K for the hx40. NOT good. Not for the poorer flowing head designs we DSMers use.

The 4g63 won't get spool earlier. It will be about the same as any other 2.0 honda. Can you imagine only stock boost or less by 5000rpms? You'll have a peaky engine that will do terrible at the track.

This is also assuming one would be using a non-divided exh manifold with a setup like this I would assume correct?

[ceedawg]

Originally Posted by dsm-onster

I see 20psi with my nearly identical h1c by 3500rpms with the bep housing, milar cams, the same intake manifold, and an evo3 exhaust manifold. My small bep housing isn't showing any signs of restricting my setup AT ALL. I've found out a little trick now to get the weak sprung ebay external gate to hold to whatever boost I want (a little different from the way TiAL recommends with a MBC). No blowing open or drop in boost at 8K so far.

Where would Slippi84 be?. . . with a much bigger turbine wheel, a much bigger turbine housing, a much bigger compressor wheel. And probably a little less flowing head. Likely with an intake manifold upgrade. Most imporantly for Slippi84, the small bep housing has proven itself with the hx40. Why don't you like it? Heat spins a turbine wheel. No one has recorded the backpressure. We don't know if it's too much.

Based on what I've been reading in the BW turbo threads here and the tests Steve93Talon has done on his BW's with the .55,.70A/R housings,the .55AR housing is a real choker and creates a tremendous amt of backpressure which will also create enuf room for detonation and severe heat under high boost. He picked up more mph and power with the 70A/R housing in the 1/4 mile.


I am going to go out on a limb and say that there has also got to be a reason why mitsu uses a bigger divided 10.5 cm housing (about equivalent to a 70AR housing) and not the old 7cm(48A/R) turbine housing with the 20g on the Evo 9 because it is a more efficient set up or am I off base here??

[dsm-onster]

Good point about BW turbos. As BEP sells them with their housing. But remember that a turbine housing can perform very different with a different turbine wheel. I agree that there COULD be lots more back pressure than advisable with an hx35 turbine wheel. But, it seams not to be enough to hinder an hx40 turbine wheel. After all isn't the turbine wheel the primary deteminant of backpressure? It uses a certain amount of exhaust gases to keep the turbo spooled. A more efficient wheel will allow more gases to be wastegated, lowering backpressure. And a larger wheel is a "bigger hole". So back pressure builds later.

Don't forget that the twinscroll turbines like the evo8 and evo9 have the larger TOTAL area because each pulse only sees half the turbine housing a/r. Each pulse is seeing about the eqivalent of a 5cm^2 housing. There is a longer time between pulses in each division so there's way more time to expel the gases before the next pulse builds on it, keeping backpressure build up down.

[ceedawg]

Originally Posted by dsm-onster

Good point about BW turbos. As BEP sells them with their housing. But remember that a turbine housing can perform very different with a different turbine wheel. I agree that there COULD be lots more back pressure than advisable with an hx35 turbine wheel. But, it seams not to be enough to hinder an hx40 turbine wheel. After all isn't the turbine wheel the primary deteminant of backpressure? It uses a certain amount of exhaust gases to keep the turbo spooled. A more efficient wheel will allow more gases to be wastegated, lowering backpressure. And a larger wheel is a "bigger hole". So back pressure builds later.

Don't forget that the twinscroll turbines like the evo8 and evo9 have the larger TOTAL area because each pulse only sees half the turbine housing a/r. Each pulse is seeing about the eqivalent of a 5cm^2 housing. There is a longer time between pulses in each division so there's way more time to expel the gases before the next pulse builds on it, keeping backpressure build up down.

Yes you r 100% correct about the turbine wheel and backpressure especially if the turbine wheel is smaller than the compressor wheel.(bad thing)

So your agrgument is very possible about the .55AR 's efficiency with the bigger HX40 turbine wheel,but I'd still like to think that the benefits gained as far as power,less chance for the car to detonate under high boost ,etc, etc are better and more reliable longterm with a bigger housing no?


Definitely you will see more topend power as well I believe. But yes the turbine wheel can have a lot to do with a turbo's efficiency and backpressure. You r definitely correct.

[1gDSM4g63]

Well the wings on the blade were minorly bent on my HX40 and while it was at the rebuilt shop I decided to switch to the t3 .70 a/r housing. Hopefully if I can accepted the top-end power versus the lag.